Sunline RV Forum
Sunline User Photos

Go Back   Sunline Coach Owner's Club > Technical Forums > Towing and Tow Vehicles
Click Here to Login

Join Sunline Club Forums Today


Reply
 
Thread Tools Search this Thread Display Modes
Old 10-08-2019, 12:57 PM   #1
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
New Truck with old Trailer, Sway issues

This is a problem that I was asking JohnB about, more specifically about my trailer leaf springs, and he asked me to start a new thread. So I will give some basic background, but so I don't have to rehash everything twice, I will give a link to the 5thGenRams forum where I have been posting about this issue.

The new tow vehicle is a 2019 Ram 1500 crew cab, 5.7' bed, Bighorn with the 5.7 Hemi, 3.21 gear.
The trailer is a 1997 Sunline T2670 Solaris.

My first thought was it was an issue with the truck, but after doing some digging, I'm going to check some things on the trailer before I blame the truck. So I don't have to go through the details twice, if you have interest in this, see these 2 links. Some of the info is in the posts, but some info about truck is in my signature.

https://5thgenrams.com/community/thr...-rating.14333/

https://5thgenrams.com/community/thr...control.14349/

I will start a new thread about my trailer suspension to try to address potential trailer issues under "Repairs and Maintenance" that may be part of my sway problem.


An interesting side note is back in 2002 when I bought the Sunline used and bought a new truck at the same time, both the truck and RV dealer said the 2002 Chevy Express 1500 would do fine for pulling the T2670. Well after making my 1st trip to South Dakota and almost burning up my transmission, I believed that GM didn't do a good job on trailer towing and testing. I thought you needed to de-rate the factory rating by 20-25% because I thought the rating were only good for flat grades and didn't do a good job in hills and mountains. I got a little more confidence recently that the truck manufacturers are doing more testing and following a fairly new standard, SAE-J2807 that was written about 10 years ago that all of the manufacturers use. If you are a information junky, than watch this link that shows some of the testing on a Ram 3500. It looks like they are more serious about getting the tow rating right and allowing comparisons across the board.

https://5thgenrams.com/community/thr...-dually.14371/
Attached Images
File Type: jpg 20191002_104630_resized (002).jpg (62.4 KB, 14 views)
File Type: jpg 20191006_110828_resized (002).jpg (85.5 KB, 135 views)
__________________

__________________
RRS2670 is offline   Reply With Quote
Old 10-08-2019, 04:41 PM   #2
Senior Member
 
Join Date: Sep 2011
Location: Connecticut
Posts: 308
SUN #2943
Tod Osier is an unknown quantity at this point
My first thought is that is a lot of camper for a 1/2 ton, a real lot for me. P rated tires are not ideal for tow vehicles. When we bought our tundra it came with p rated tires and they were gone after the first test drive with the camper (a t1950).
__________________

__________________
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


2006 Sunline T-1950
2019 Ford F-250
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tod Osier is offline   Reply With Quote
Old 10-08-2019, 05:32 PM   #3
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
My Ram's GCWR is 13,900 lbs, the truck has 7100 lb GVWR. I'm only weighing in at 11,400 and 5900 lbs with ~675lb tongue wt. Not close to either truck axle rating. Trailer weighing in at ~5500lbs, with a GVWR of 7k lbs.

I didn't realize they make a tire that is between P and LT tires. If the size doesn't have a P or LT, it is considered a SUV/light truck, aka 1500's (no letter in front of size). I was looking the size up going what kind of tire is this? They make a SL (standard load) and an XL (heavy load) that adds a little bit to the tires to allow higher air pressure ratings on the tire. Technically the tires I have, a Bridgestone Dueller HL Alenza's have the correct load index for the axles, but lack the extra rating of an LT (used on 2500 and 3500 trucks) that has the C-G sidewall and pressure rating.
__________________
RRS2670 is offline   Reply With Quote
Old 10-08-2019, 11:15 PM   #4
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Hi Russ,

You have done a lot of good work trying to sort out your issues. There are many variables in the truck, WD hitch and camper that have to be optimized to create a stable towing rig. You hit on a lot of them, but yet there is still something still not cooperating. I suspect it's not going to be as simple as, just adjust this and all will be good. Especially since you have dialed in this same camper with 2 prior trucks and all was good.

I'm willing to help you dig into this and review if you can bear with me. The only way I know how to sort out these kind of issues is to step back, review and check each setup item. Come at it with an open mind as somewhere there is an issue or a combo of issues creating your noted instability.

Here is a start on some questions as I cannot find them on your 5th Gen site links.

1. You listed these weights from your WD adjustments and the scaled weights.

Quote:
A. Ram 1500 Bighorn with me, some tools and hitch, trailer disconnected: 5900 lbs

B. Ram & trailer with WDH hooked up, 4th link: Steering axle - 3240 lbs, Drive Axle - 3240 lbs , trailer axles - 4880 lbs

C. Ram & trailer with WDH disengaged, 1st link, chain loose: Steering axle - 3000 lbs, Drive Axle - 3600 lbs, trailer axles - 4720 lbs
Can you provide the front and rear truck axle weights split from your scale ticket for item A above? The truck is listed as 5,900# loaded and unhitched. I need to see the unhitched axle weight to figure out the front axle loading. If you have any new weights, please add them too.

2. What are the front and rear axle ratings from the truck door sticker?

3. I can't get the PDF to fire on the 5th gen site that seems to be something on the tires. Says I need to be a member. I don't know what is in that PDF, it may help. You can attach a PDF to post reply here. Scroll down in the advanced posting mode and see "Attach files" That will allow you to upload a jpg. or pdf to your reply.

4. What size tires are on your truck?

5. What are the door sticker air pressures listed, and what were they when you were towing?

6. Just confirming, when you say "WDH hooked up, 4th link", is that counting links from the slack end of the chain? Meaning it looks like this in your pic. below. Your snap up hook is on the 4th link from the slack end of the chain.


7. The sway event you are feeling. Can you try and describe what you feel in the truck when the towing instability starts, what event around you acted on the truck & camper, (semi passing, hard wind gust etc) and the speed when it happened? Also, did the sway event require you to make steering corrections, and describe magnitude of the correction if any. Mild correction, medium correction, many steering corrections to get stable. I'm trying to get a feel for what you are feeling inside the truck.

8. How is the towing stance of the camper when hitched with WD engaged when the sway event started? Camper nose high, camper level, camper nose down. If nose up or down, about how much in inches when measured at the ball coupler or just behind it.

This will help fill in some of the missing pieces for me and I'm sure prompt more questions.

Hope this helps

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-09-2019, 10:39 AM   #5
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
Hi John,
Here's some answers to your questions. But I'd like to also clarify one of my statements about towing this trailer with my other 2 vehicles. My short term memory isn't as good as my long term memory. When I said I towed this trailer with 2 other vehicles and didn't have any issues, that's what I remembered. But in 2015 when I got my used 2011 Silverado, my wife was going through some health issues and I only took 2 long vacations with this vehicle. I looked at a log I keep (more of a to do list after each trip) and I noted on the first trip in 2016, that the trailer swayed to much. It looks like I repacked and adjusted bearings, brakes, rotated tires and added a Hellwig rear sway bar to truck before my trip last year to Estes Park CO with the Silverado. I make no mention after the trip of having any issues, so I'm assuming I didn't experience any sway.


Trip to truck scale is a 40 miles, one way trip on fairly flat land, with elevation change of only ~100' from my home to truck scale facility, This is mostly freeway driving, probably only 5 miles on stop and go roads to access highway.

1. First my weigh-in, (10/2/19) inexperience on the scales showed (what my Ram forum observation post was based on), I pulled up and had both truck axles on first pad. I went back again for round 2, 4 weigh-ins done 10/6/19.

A. Truck by itself w/hitch, Steering Axle - 3280, Drive Axle - 2620, GW - 5900

B. Truck and Trailer, WDH chain on 4th link - SA - 3220, DA - 3300, Trailer Axle - 4860, GW - 11,380

Note: this is just to see how much WD changes by changing chain links (less force) to the 3rd link.

C. Truck & Trailer, WDH chain on 3rd link, SA - 3120, DA - 3460, TA - 4820
GW - 11,400

Note: on Ram Forum, some discussion of about tongue wt and how it affects handling, I decided to change my tongue wt for ride home (Weigh station 40 miles away from home). Looking back at some trailer info and notes during setting up trailer on 2002 Chevy Express, I see that in 1997 the Hitch weight was 485 lbs on the UVW of 4784 of new trailer, which is only ~10% tongue wt. 2001+ model years on a T2670, Sunline upped the tongue wt to ~15%. Not sure if they changed the axle locations on the newer models. Since all of the issues I had setting up the Chevy Express originally, I've always targeted 650-700lb tongue on the ~5500 lb (GCW 11,400 - 5900 truck wt) Sunline, or ~12-13%.

For this test, I removed the 2 -30 lbs (nominal size but the mostly empty cylinders actually weighed 32 and 29 lbs, ~61 lbs total) LPG cylinders from the tongue to inside trailer. Placed one in extreme rear and one over axle.
Measure tongue wt before, ~675, after LPG move, ~630 using Sherline scale.

D. WDH back on 4th link for drive home, SA - 3260, DA - 3200, TA - 4940, GW - 11,400.

The trip home with the change tongue wt, had much more unstable feeling then the 40 mile trip to weigh station.

2. Axle ratings, FA- 3900, RA - 4100, GVWR - 7100

3. The PDF to large to attach to this forum, here's link. This just talks about tire load range vs load index.
https://www.discounttire.com/learn/l...nge-load-index

4. Bridgestone Dueler H/L Alenza 275/55R20 113T M&S

5, Truck sticker front and rear tire pressures 36 psi.
1st trip for weigh-ins for the post made on the Ram Forum, I used listed tire pressures.
2nd trip to scales noted here, I raised the rear tire pressure to 41psi (44 is max listed on tire), 38psi front.

The trailer tire are Goodyear Marathon with 50 psi max pressure.
1st trip to scale, 36psi since I wasn't at full 7k GWVR.
2nd trip to scale, raised all pressures to 50 psi.

Higher tire pressures on 2nd trip, along with the upgraded solid Hellwig sway bar on the truck made a noticeable difference, was more comfortable going 68-70mph.

6. Confirmed, I count the link hooked up from the slack end.

7. This is were it gets very subjective. I have to say this is more of a oscillation or wallowing of the vehicles if that makes sense. It is unstable feeling from a very slow speed. It doesn't require any steering corrections, it just makes you hold your speed down, as the higher the speed, the more un-stable it feels. The vehicle just doesn't feel planted or secure. Both of my scale/test runs were light traffic and low winds. I could feel that the trailer was there, where my memory says with my 2002 Chevy express, after much work, I never hardly notice a trailer behind me. I could go 75-80mph on occasion and it felt rock steady. I feel uneasy with the current setup. The 2nd trip with the raised tire pressure was definely better and I drove at higher speeds, but not perfect yet.

8. After re-setting my hitch height and angle, the trailer and truck are as close to level as you could probably get. The trailer is with in a 1/2" difference from front to back measuring the frame to asphalt in picture. The picture in my first post of the other side taken at same time. One difference from my previous trucks is my WDH spring bars are on the 4th link on the Ram. I always used the 3rd link on 02 and 11 Chevy's setup. That's why I got weights at both settings.

I hope this answers all of your questions. Thanks Russ.
Attached Images
File Type: jpg 20191002_104556_resized (002).jpg (57.0 KB, 5 views)
__________________
RRS2670 is offline   Reply With Quote
Old 10-09-2019, 11:36 PM   #6
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Hi Russ,

Thank You for the great info. This helps to rule out certain setup parameters.

I checked over your scale numbers and the truck WD settings, and they look in line with a good setup. And your side pic of the WD hitch shows it is setup well with the trailer. So that is good too. Here is a recap, maybe done a little different than yours, but outcome the same.

From your scaled weights, and using the 4th link on the chains from the slack end, your truck front axle (FA) is 60# less than unhitched weight. This comes out as:

Truck FA unhitched is 3,280#,
Truck FA with dead weight on ball (hitched but no WD engaged) is 3,000# from the 5thgen post.
Truck FA on 4th link with WD engaged is 3,220#

Truck GAWR FRT: 3,900# Frt axle with WD engaged 4th link: 3,220 680# excess capacity
Truck GAWR Rear: 4,100# Rear axle with WD engaged 4th link: 3,300# 800# excess capacity
Truck GVWR: 7,100# Truck GVW with TT & WD engaged 4th link: 6,520# 580# excess capacity

Truck GVW no trailer: 5,900#
Truck GVW with trailer hitched but no WD engaged: 6,600#
Trailer TW using scale numbers: 6,600#-5,900# = 700# TT Loaded TW.
Trailer axle weight with no WD engaged: 4,720# + 700# TW = 5,420# TT GVW.
TT Tongue weight percentage: 700#/5,420#= 12.9%
TT dry weight from 97 brochure: 4,455# (Ideal is to get this off the camper weight sticker if it has one)
Cargo added to camper: 5,540 loaded TT GVW – 4,455= 1,085#

Summary:

700# TT loaded TW removes 280# from truck FA.
4th link on hitch chains restores 220# to truck FA.
Front axle load restoration: 79%
TT loaded TW: 12.9%

All truck axles and GVWR on truck under ratings with excess capacity.

Your WD hitch setup looks in line. Good job.

Your TT towing stance is level. Good job.

Your camper loaded TW is 12.9%. This is acceptable. Just watch it does not go a lot lower. Lighter trailers are easier to have larger drops in TW percent with common gear changes.

We need to dig deeper now. Your good responses and seeing the above setup data brings these 3 questions to the forefront.

1. Does your truck have the air suspension system? Some of the new Dodges do. I suspect not as you were talking about adding airbags in the 5thgen post. Need to confirm.

2. How many miles were on the truck tires approximately when you did your last towing test with the higher air pressure in the truck and camper?

3. You have owned the camper long enough that I am assuming you have had to change trailer tires a time or two. On the tires on the camper now, or past tires, have you looked at all 4 tires for wear patterns on the inside or outside edges of the tire tread? Wear pattern meaning a tire that is not wearing even across the face of the tire. If you have wear patterns, please describe which tires have them and which don’t?

Before I give you a summary of the rest of what “might” be happening, I need to understand the 3 items above better.

Hope this helps.

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-10-2019, 06:01 AM   #7
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
John, thanks for the summary, here's the 3 answers to your questions.

1. No Air suspension,

2. 4500 mi

3. Yes I replaced the tires but they are over 10 years old now. I am not replacing them until next spring since we aren't taking trailer out anymore this year. The tires have no side wall dry rot and the treads are just starting to show some small cracking. Wear is even on all tires, and plenty of tread left. I'm going with Goodyear Endurance tires that are the replacements for the Goodyear Marathones that are currently on there. Goodyear upgraded the load rating from a C to a D on the Endurance.
__________________
RRS2670 is offline   Reply With Quote
Old 10-10-2019, 01:16 PM   #8
Senior Member
 
henryj's Avatar
 
Join Date: May 2008
Location: Ontario
Posts: 641
SUN #597
henryj
I wouldn't be too hasty to blame the RAM for your problems or throw money at it messing with the hardware on a brand new truck. My scale numbers are very similar to yours except TW is closer to 15%. Given that you've previously towed with 2 different trucks, the change to RAM may be part of the issue, but not all of it. While TT's are more susceptible to cross winds and semi bow waves than 5th wheels, they should still tow straight with occasional minor corrections for gusts with no nervousness on the driver's part. These minor twitches are not speed related and the TT should be rock solid at speeds up to 75 mph. While I don't recommend sustained travel at these speeds, I try to pass quickly and don't hesitate to exceed 70 if necessary. It sounds like you can't do that and have more of a speed related back and forth oscillation--anti sway is not working--rather than an occasional single twitch--that the anti sway is catching--which requires a minor steering correction.

IMHO the hitch you are using with 2 friction bars is a kludge and you successfully masked its ineffectiveness with mods to the van. While the big$ Hensley would certainly solve your problems, I would switch to Reese DC, arguably the best of the rest, for a much more cost effective solution.

Where the RAM does have an issue is that it, like our '19 F!50, comes with mediocre factory tires that are ill suited to towing a trailer. I won't go into the rationale, but I replaced our factory GY with BFG All-Terrain LT255/70R18 LRD. This is an excellent tire on tirerack.com and the LRD suits a 1/2 ton much better than LRE. It also happens to be available in your size. We have approximately 10,000 mi on this tire with 8000 mi towing and I will definitely buy it again. It is very quiet despite the aggressive tread and has the "3 mountain peak snowflake" symbol on the sidewall. It doesn't have the ice friendly rubber compounds of a Blizzak, but I'm hoping it will be good enough for year round use. There are other even more highly rated tires, but not in the 255/70 size I was looking for, so check the other brands in the ratings tables for your size.

A couple of things to watch for on any replacement tire is that tire shops from Costco on down will not mount a tire with a lower Load Index than is on the door sticker. Also, while tires are supposed to have common sizes, there can be some significant differences in tread and section width when moving from P to LT. Check that you have the clearances and Load Index needed to mount the tire of your choice.

Bridgestone Alenza

Alenza ranking

BFG All-Terrain T/A

All-Terrain T/A ranking

Henry
__________________
2019 F150 3.5L Max Tow
2015 Silverado 1500 NHT
2014 Arctic Fox 22G
2005 Sunline T-2499
henryj is offline   Reply With Quote
Old 10-10-2019, 10:21 PM   #9
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Hi Russ,

I got tied up, and I can't get to your summary until after Sunday this week.

I would like a clarification on this paragraph below. The blue highlight below about the very low speed. What approx mph is the very low speed where the instability starts and builds from there?

Quote:
Originally Posted by RRS2670 View Post

7. This is were it gets very subjective. I have to say this is more of a oscillation or wallowing of the vehicles if that makes sense. It is unstable feeling from a very slow speed. It doesn't require any steering corrections, it just makes you hold your speed down, as the higher the speed, the more un-stable it feels. The vehicle just doesn't feel planted or secure. Both of my scale/test runs were light traffic and low winds. I could feel that the trailer was there, where my memory says with my 2002 Chevy express, after much work, I never hardly notice a trailer behind me. I could go 75-80mph on occasion and it felt rock steady. I feel uneasy with the current setup. The 2nd trip with the raised tire pressure was definely better and I drove at higher speeds, but not perfect yet.
I'll explain more on Sunday, 2 years ago I experienced a feeling like you are describing on my F350 and T310SR. I did manage to work my way out of it and the rig is once again stable as it has always been. The learning never ends. Before I go to that suspect, I want to make sure what approx. speed this unstable feeling on yours, starts.

Thanks

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-11-2019, 09:57 AM   #10
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
Hi JohnB,

I don't really know what speed I start feeling this very slight swaying, but I think it starts under 20 mph, and that's a guess. I had a friend (someone that has a TT) along on one of the trips to the scale, and he noticed it and commented it didn't feel right. Coming back from the 2nd trip I was watching the trailer in the mirror, you could see a slight movement at the back of the trailer. It was like the trailer wasn't tracking straight. The feeling almost feels like if something was off balanced.

The reason I started wondering about the leaf spring bushings was when I park the trailer in the driveway, I have to make a tight cut to get it where I want it. I back in with the truck and trailer straight inline for a bit, but cut the steering hard to push the nose of the trailer in a kind of cutout in the driveway. After I parked, I noticed that the axles had shifted, because the front one is probably being pushed more and the back axle kind of pivots. The tires just after parking looked way out of line with one looking toed in and the other toed out (from drivers side, didn't look at the other side). When I later moved the trailer out in the court, the wheels seemed to get back to their relaxed position and seemed inline. Just wondering if there is enough slop in the bushing and maybe the tires over the years have got out of balance, even though I see no wear indication of this. Just throwing ideas out.
__________________
RRS2670 is offline   Reply With Quote
Old 10-14-2019, 09:02 AM   #11
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Hi Russ,

Reviewing what you have posted here so far, and on the 5thGen Dodge forum, this is my summary. Consider it an “opinion.” I can and will expand more on each topic if you need/want it, ask. Glad to expand on this more. This kind of problem would be easier to troubleshoot if I could ride in the truck with you, but I hope this helps.

I want to point out, when towing trailer trailers (TT) on the ball many feet behind the rear axle (rear overhang), there are many factors in the truck, WD hitch, and the TT that have to optimized to create a stable towing rig. You cannot just look at one or 2 factors; you have to look at all of them and optimize each. Every truck, WD hitch, and truck combo can have its own personality. Interactions between factors also exist making some towing combinations even harder to become stable.

I’ll start with a summary and then some backup details.

Summary: Below is several key areas of your rig (not all, but the normal ones) which need to be optimized to create a stable towing rig.

Positive contributors to an optimized rig.
- The loaded tongue weight (TW) of the camper is 12.9% loaded of the trailer GVW.
- Your WD hitch is set up in an optimized state. Front axle load restoration comes in at 79%.
- All truck axles and GVWR’s are under the truck ratings with reserve capacity.
- The trailer towing stance is very close to level and in an optimized.
- The TT is not in an overloaded and has reserve cargo capacity.

Acceptable contributors to an optimized rig.
- Anti-sway used is qty, 2 friction sway bars on a 26’ 10” long TT with a 5,540 lb GVW.

Negative contributors to an optimized rig.
- New tire break-in mileage, (new rubber compounds)
- Soft flexing sidewalls on the OEM tires

Other items which can be a factor to towing instability on the camper,
- Low tire pressure. For both stability and tire life, run TT tires at max cold sidewall pressure. You stated in your last test to you aired them to 50psi.
- Trailer wheel alignment. In a gross wheel alignment condition, the trailer can dog track to the left or right. If this dog tracking is bad enough, it can aggravate a stability issue in the. In your case, your 10 year old tires are not showing signs of irregular tire wear. Trailer tires that are out of alignment can wear the tire in a pattern that can be seen in 2,000 to 5,000 miles pending how far out the alignment. You reported
Quote:
Wear is even on all tires, and plenty of tread left.
I will list some highlights from your various replies below as it talks to the truck not being stable, which at this juncture, the descriptions you list appear to be pointing to the tires as the most significant area. I have not yet seen a rating on a tire for sidewall flex. This makes it even more challenging to find a tire that meets the needs of towing but allows acceptable ride when not towing. I have found a way when the tire is unmounted how to help find a tire that has stiffer sidewalls then others when comparing brands. More on that when needed.

Details on the instability feeling in the truck.

You are using the words “trailer sway” and the feeling going on inside the truck. At this point, I’m going to use the wording, towing instability, which is a better fit for what you are describing. You are not yet describing you are doing steering corrections at any speed. Please confirm that I have that correct. That is a crucial observation with not doing steering corrections.

I agree with you; you can feel the truck being unstable and it can give you the feeling it’s going to start getting worse. It is sort of like driving on ice, and you sense when you are going to start losing it. This feeling can come from two different areas or a combo of both.

Two years ago I bought new tires for my F350. For the last approx. 5 plus years I have read reports on 3/4 and 1-ton trucks that were previously stable towing rigs. Then they started to experience towing instability when buying new tires. The findings did not single out a truck brand or tire brand so far in my research. Dodge, Ford and GM’s have all reported this.

In my case, I am not on my 3rd set of Continental Conti Trac TR’s LT275/70R18 LR E tires. They are the OEM tire for the truck, and they had always worked. The first set had 25K miles on when we bought the truck used. The truck and camper towed stable. The 2nd set came at the 50K mile mark, had a nail in one tire, decided to replace all 5. On that 2nd set, we set out on an 8-hour camping trip, in the rain no less, and the truck was stable from the get-go until 2 years ago as the tires had wear and were aging out. We had a big 1,600-mile camping trip coming up, so I changed them. I, on purpose, stayed with the same brand and style. More on why if needed. Non towing, everything was okay. Then after about 300 miles on them, I started towing. Now towing is not good. The rig reaction is very different.

You described this when I asked you how it felt inside the truck.
Quote:
7. This is where it gets very subjective. I have to say this is more of an oscillation or wallowing of the vehicles if that makes sense. It is unstable feeling from a very slow speed. It doesn't require any steering corrections, it just makes you hold your speed down, as the higher the speed, the more unstable it feels. The vehicle just doesn't feel planted or secure.
What you are describing can be caused by tires. OEM’s are now outfitting trucks with very cushy riding tires. They even have them tweaked to ride better than what you can buy in the aftermarket on the same tire. While a cushy riding truck helps sell it, it does not help when towing TT's.

I have personally had 2 different tire events in my TT towing career and both came when I changed to new tires. I also have helped others with tire issues. My first event was on our 2003 K2500 Suburban. In this case, I was up against soft flexing sidewalls of the first generation Michelin LTX LT truck tires.

The 2nd event was 2 years ago was with the F350 Continental Conti Trac TR’s LT truck tires. These had no sidewall flex issues, but they had what some call new tire squirm. I have not been able to get a technical explanation of what is going on with the rubber, but it feels like a shift in friction to the road. The truck feels like it is not firmly planted on the pavement. It is hard to describe. It is like driving on ice, and you know the feeling the truck wants to break free and start sliding. I do not have to make steering corrections, but I can for sure feel it. It is like I’m driving on slippery road conditions. Sure enough, I ended up with this new tire wear in issue that after 3,500 to 4,500 miles, the problem went away, and now the truck is stable once again. This is the same new break-in problem others have been reporting. This was not a tongue weight issue as I have 16% loaded tongue weight (1,600# on a 9,950# GVW camper). It’s not sidewall flex, as I can’t rock the truck by hand. The suspension is very stiff, being a 1-ton truck. I have the dual-cam WD hitch. The only area that changed was the truck tires. At first you suspect the WD hitch or the DC. So you check it. Nope, not there. It has to be in the truck. It seems the newer tire molding process or rubber compounds used causes this break-in issue on some brands of tires.

You also stated this:
Quote:
I don't really know what speed I start feeling this very slight swaying, but I think it starts under 20 mph, and that's a guess. I had a friend (someone that has a TT) along on one of the trips to the scale, and he noticed it and commented it didn't feel right. Coming back from the 2nd trip I was watching the trailer in the mirror, you could see a slight movement at the back of the trailer. It was like the trailer wasn't tracking straight. The feeling almost feels like if something was off balanced.
The low-speed note and your estimate or 20 mph help point to some things. The trailer not tracking right could be from this same issue. It’s tracking to what the truck is doing. If you had a mechanical towing imbalance, like low tongue weight, it takes vehicle speed to set the sway off. From my towing research, 45mph is a critical speed factor where in that range of speed, ~ +/- 5 mph an improperly balanced trailer will start acting up if nothing stops the reaction. If you start feeling this effect towing at low speed, ~ 20 to 30mph, you are not necessarily into a sway event yet. But that does not mean you’re not having feeling instability inside the truck that something is about to start happening.

In 2007 GM redesigned the Chevy Suburban. I helped a friend who was towing his camper with the 2004 prior generation Suburban for 3 years and had no issues. When he hooked the same camper up to the new 2007 Suburban, he had significant towing stability problems. Yes, GM changed the front and rear suspension, but they also changed tires. He brought it over to our place, and I fixed his WD hitch setup that was all out of whack. WD was wrong; the DC settings were way out, and the trailer was 2 ½” too much nose high. He had OK tongue weight, 13%. We set out on a test drive. He was driving, and I was in the passenger seat. The speed was at 25 to 35 mph. He stopped at a stop sign and went into a 90 deg turn. The back of the truck did a full wag back and forth. He said it felt better but was still there. To me, this is not good at all. This is bad. The tires were already at max cold tire pressure, but the side walls were way too soft. The truck was flexing in the side walls. The ride of this truck non-towing was excellent, but towing it was bad news with those new tires.

Your 5th gen post stated this:
Quote:
Today I installed the Hellwig solid sway bar, I used the second hole, which is supposed to be a little stiffer than the stock position. I took truck for a ride and honestly couldn't tell much if any difference. I plan on taking out the trailer again to see if it's any different. One thing I noticed while under the truck and just pushing on the receiver, all of the flex is coming from the tires. You don't need much force and you get some sway in the sidewalls. This would be amplified with a 5500 lbs trailer on it. The suspension does seem pretty tight though.
Here is a test you can try. Go to the back of the truck, on the rear bumper/fender, push hard from the side of the truck to get it rocking left to right. While pushing back and forth, or trying too, look at the front tires. Hone in on the edge of the wheel/rim to the tire sidewall. If you see the front of the truck rocking in the tire sidewall, ( the rim is fixed rigid, the tread to the pavement is fixed rigid, the truck is rocking in the sidewall flex, then you can see that is part of your issue. The front and rear tires have to hold the truck stable. There is no brand high friction WD anti-sway hitch that will fix soft flexing sidewall tires.

You stated this:
Quote:
5, Truck sticker front and rear tire pressures 36 psi.
1st trip for weigh-ins for the post made on the Ram Forum, I used listed tire pressures.
2nd trip to scales noted here, I raised the rear tire pressure to 41psi (44 is max listed on tire), 38psi front.

The trailer tire are Goodyear Marathon with 50 psi max pressure.
1st trip to scale, 36psi since I wasn't at full 7k GWVR .
2nd trip to scale, raised all pressures to 50 psi.

Higher tire pressures on 2nd trip, along with the upgraded solid Hellwig sway bar on the truck made a noticeable difference, was more comfortable going 68-70mph. 5, Truck sticker front and rear tire pressures 36 psi.
1st trip for weigh-ins for the post made on the Ram Forum, I used listed tire pressures.
2nd trip to scales noted here, I raised the rear tire pressure to 41psi (44 is max listed on tire), 38psi front.

The trailer tire are Goodyear Marathon with 50 psi max pressure.
1st trip to scale, 36psi since I wasn't at full 7k GWVR .
2nd trip to scale, raised all pressures to 50 psi.

Higher tire pressures on 2nd trip, along with the upgraded solid Hellwig sway bar on the truck made a noticeable difference, was more comfortable going 68-70mph.
Your tests reported that increased tire pressure helped create a more stable and notable difference.

After you try the truck left to right rocking tire sidewall flex, test, air up all 4 tires to max cold sidewall pressure. Test again if there is still excess sidewall flex if so, you ran out of adjustment. You need a stiffer sidewall tire.

You may be suffering from new tire wear in issues along with sidewalls flex at the same time.

When you changed suspension bushings on your prior truck, and it helped towing stability, I agree on the “truck” that can help as it is the tow vehicle. On the trailer, it is being pulled by the truck. The trailer suspension dynamics are different than truck dynamics. Remember there is a slow speed component to your issue. Slow speed and even a dog tracking camper does not induce truck stability issues. Unless your braking hard, all the play in the TT suspension when towing is pulled in one direction. On the truck, bushing play goes on both directions affecting towing stability. As to worn leaf spring bushings and equalizer bushings/shackles, I have had to rebuild several trailer suspensions that were totally shot. All the spring pins spinning, the equalizer center pivot was heavily worn badly, shackle links holes heavily worn, all bushings gone, but the trailer still towed well. The heavy worn suspension will leave you stranded on the side of the road with broken shackle plates or an equalizer. Just they normally do not affect towing stability. That said, if you have a cracked leak spring, that can cause towing issues.

To your comments on adding airbags to the truck, airbags do have their place. But this is not a good use of them to correct truck stability issues. Your WD hitch is doing what it is supposed to do, move weight back to the front of the truck from the rear axle. The airbags will not transfer weight to the front axle or TT axles and can make WD settings more complex.

Read this over and let me know your thoughts. I can expand more on this as needed.

Hope this helps

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-14-2019, 09:05 AM   #12
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Also to add, I see HenryJ has joined in the discussion. This is good. Henry and I go back a long time. He has a lot of towing experience across various trucks and campers and his input to towing issues is always good conversation.

Glad to see you back posting again Henry.
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-15-2019, 08:56 AM   #13
Senior Member
 
Join Date: Apr 2011
Location: Maine
Posts: 2,990
SUN #2097
mainah is an unknown quantity at this point
Me, I would try a shorter tow bar.
__________________
mainah is online now   Reply With Quote
Old 10-16-2019, 11:16 PM   #14
Moderator
 
Sunline Fan's Avatar
 
Join Date: Dec 2006
Location: Michigan
Posts: 5,994
SUN #123
Sunline Fan is an unknown quantity at this point
'97 Sunlines just look sooo good being towed!

While I don't have much technical stuff to add, I can add my own experiences.

My previous Excursion had Bridgestone Dueler AT Revo2s, which were an LT tire. Even aired up, this tire caused a lot of sway with the trailer. It was a bad experience even though I didn't tow with it much.

The original tires on my current Excursion, BFG Rugged Trail LTs, were awesome towing. Could even run them at 65 psi (out of 80) and still have a comfortable towing situation.

After those aged out, I switched to Michelin LTX M/S2, also an LT tire. On the Excursion forums, it's the best tire you can buy and is the longest lasting, with people getting like 70k easy out of a set. I only have maybe 15k on them and they still look brand new, despite being almost nine years old now. They should be replaced soon due to age, but I don't even put 1k a year on them, so I'm not in a hurry to.

Last year, I made the trip from Michigan to the SunlineClub meet and greet in NW Ohio for the first time, with my '97 Sunline. The above Michelins on the Ex, and fresh Goodyear Endurance on the trailer at 65 psi (out of 65). Excursion also running at 65 psi. With my single friction sway control that I've used for years, the whole rig was all over the highway. Granted the side wind was a bit strong on the trip down, but it was not trailer sway. When someone passed, I could tell it wasn't the trailer swaying, it was the combination of both moving around in the lane. I remembered my conversation with John previously about his experience with Michelin LTX and told him that my experience was mirroring it.

I've pretty much given up towing my '07 Sunline with the Excursion because it's an awful experience. I borrow my dad's dually when I do. The higher profile makes everything even worse.

This year, I returned to the SunlineClub M&G in Ohio again, same setup with same tires. The only change is I increased the tire pressure in the Michelins to 75 (out of 80). It made for a much more enjoyable trip with minimal movement within the lane. Even passing trucks caused almost no movement, and I was able to stay around 68 mph the whole trip. Granted this is with the low profile trailer, but I would hope the high profile Sunline to be much more under control too.

Even though it was a bit long winded, my vote is to change to LT tires.
__________________
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR
Sunline Fan is offline   Reply With Quote
Old 10-17-2019, 02:25 PM   #15
Junior Member
 
Join Date: Sep 2016
Location: Maine
Posts: 9
SUN #8805
dtcaswell is an unknown quantity at this point
Forum members: I'm done towing for this season, but will need to purchase new truck tires before the 2020 summer tow season. Current tires are not LT and I to feel what Russ and JohnB have explained as instability feeling of on ice in the lane at low speeds and high. So any suggestions on a good solid sidewall LT tire would be appreciated. 2011 RAM 1500 Big Horn and 2004 Solaris 2553. thanks, Dave
__________________
dtcaswell is offline   Reply With Quote
Old 10-17-2019, 07:22 PM   #16
Junior Member
 
Join Date: Apr 2007
Location: New York
Posts: 15
SUN #250
HurleyMan
I'm not reading this looooong thread but I did skim through and see your picture close-up of the hitch. I initially had a little more sway than I liked with my truck when I bought it. I resolved it by shortening the drop hitch going into the receiver. I had to drill a new hole for the pin and cut some length off of the drop hitch so it wouldn't hit the spare tire under the bed.This brings the ball hitch in a few inches closer to the truck. Resulting in a noticeable improvement in sway. Good luck!
__________________
HurleyMan is offline   Reply With Quote
Old 10-18-2019, 04:51 AM   #17
Senior Member
 
jim44646's Avatar
 
Join Date: Jul 2012
Location: Ohio
Posts: 1,008
SUN #4040
jim44646 is an unknown quantity at this point
To bad tires don't give a sidewall flex rating. Different tires even marketed as LT tires have different side wall flex. A good test of this is to have tires inflated to proper psi and have a buddy push sideways on the back of tow vehicle and watch how much your tire sidewalls flex. It's amazing how different tires respond.
__________________
jim44646 is online now   Reply With Quote
Old 10-18-2019, 08:59 PM   #18
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Quote:
Originally Posted by dtcaswell View Post
Forum members: I'm done towing for this season, but will need to purchase new truck tires before the 2020 summer tow season. Current tires are not LT and I to feel what Russ and JohnB have explained as instability feeling of on ice in the lane at low speeds and high. So any suggestions on a good solid sidewall LT tire would be appreciated. 2011 RAM 1500 Big Horn and 2004 Solaris 2553. thanks, Dave
Hi Dave,

I have a good friend, who tows his 27' Coachman and 34' Cougar camper with 2012 1500 Ram, Crew cab, short bed, rear coil springs, no air suspension. He has the 5.7 Hemi. He is using Cooper Discover 275-60-R20. I helped him with his hitch and I even road around the block in it. He has not reported any towing issues with the Cooper tires.

On LT tires, Henry J had some suggestions on brands. And I agree on a 1500 truck, see if load range D is available. Jumping all the way to LR E can be a hard ride jump in some cases.

In my search and by close towing friends & family using 3/4 ton trucks, these brands have been shown to have side walls that work well towing.

Cooper Discover HTP
Mastercraft Courser HXT (also part of the Cooper tire co)

Firestone Transforce.

Continental Conti trac. (but the new ones need approx 4K miles break in)

When I went to NTB for my last Continental Conti trac, I was worried they may have been discontinued. I also has a flat on one of them. They had a very well seasoned manager and we were talking tires as I needed 5 of them. He started talking about the Michelin LTX and I quickly dismissed this as the side walls for me, were too soft.

He agreed, the Michelin were the softest side walls of all the tires he has. He said we can go feel the tire sidewall and tell. So with my flat off the rim, we pulled on the sidewall/bead and felt an unmounted tire sidewall flex.

Then went into his storeroom and started pulling on LT tire sidewall/beads for stiffness. For sure, the Michelin hands down was the softest by a long run. Since I knew the Continental Conti trac feel and it works on my truck, which was very stiff, we tried many brands which felt the same stiffness. Some lots stiffer, almost solid, some softer.

We ended up with BFG Goodrich Commercial TA All Season 2 having the closet side wall stiffness. Just BFG does not make my size.

What I learned is, a way with an unmounted tire that works for towing stability, to gain a feel for sidewall stiffness in finding a replacement. Never had that before. Then you can compare brands for other attributes as all season, tread pattern etc. For towing, you need a stiff enough tire with a ride you can live with and the tire life and cost hopefully align.

You may be able to do the side wall feel test on yours to help sort this out. Talk to the tire dealer manager and explain your problem. Ask them if he has a new tire of your existing brand/style that has issues, get a feel of it and then see if in his store room you can find then stiffer. You still do not know if it tows well or has the tire break in squirm, but you know more than you did before.

Hope this helps and let us know what you come up with and how it works.

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-18-2019, 10:57 PM   #19
Moderator
 
JohnB's Avatar
 
Join Date: Nov 2006
Location: Ohio
Posts: 10,145
SUN #89
JohnB is on a distinguished road
Something to add to the folks who may be considering shortening their WD shank to help reduce trailer instability.

The first thought is, yes, by reducing the rear overhang of the truck from the rear axle to the tow ball is something that may help. How much it reduces your current issue is not as simple to know short of trying it.

Also to note, all truck receivers are not created or mounted equal on how far they extend behind the truck. What can work for some, may not work on your truck. By shortening a WD hitch shank overhang distance, or a non WD drawbar, it can affect the turning clearance of the truck to the camper. Meaning, if you shorten the shank extension length by a few inches, (1" or 2") when you turn sharp backing up into a campsite or your driveway, you may now hit the camper body with the rear tail light or back fender of the truck that use to miss on the the original length hitch shank. The front wall knee bend of the camper sticks out the furthest on many Sunline TT's.

Suggest before drilling a new hole or cutting off the shank end, do a very slow backup to almost a jackknife maneuver as a test with a spotter. Have them tell you when to stop before you hit something. Then get out and see how much clearance between the camper outermost body is, and the truck fender/tail light. That distance may change by shortening or lengthening the hitch shank. You can then make a decision to try and shorten the shank length or not.

If your truck and camper combo can tolerate a shorter distance, then reducing the rear overhang is a benefit.

When I setup WD hitches, I always do a back up test to tell what is the crash point in a turn and memorize what that looks like in your truck mirrors so you never go that far. In most cases, the truck bumper will hit the LP tanks first or the WD hitch head arm hanging out for the mini ball of a friction sway bar will hit the trailer frame. Part of what will hit on the frame, is hitch brand dependant.

When the LP tanks or the WD hitch head are your truck crash point, that is still a lot of turning radius. If the camper front wall hits the truck, that crash point is not much of a turn and something has to change in the setup or you will some time, hit the camper by accident as the turning radius is so small. On my truck, hitch and Sunline, the truck fender clears by 1" before hitting the camper front wall, but it is clearance and it works in my case. I do not choose to make that clearance anything less than the 1". Shortening the hitch shank may reduce the front wall turning clearance. How much clearance is lost, depends on your truck setup and WD hitch.

I also do not recommend you alter a cast steel contoured shaped WD shank. A 2" solid steel bar that some WD hitches use, is different and a lot less issues altering them.

John
__________________
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC

Google Custom Search For Sunline Owners Club
JohnB is offline   Reply With Quote
Old 10-19-2019, 09:15 PM   #20
Junior Member
 
Join Date: Jul 2012
Location: Illinois
Posts: 23
SUN #4147
RRS2670 is an unknown quantity at this point
Hi John,
Sorry I didn't respond earlier, I've been out of town with no computer access.

Thank you for the detailed summary. At this point I'm waiting until next year to do anything else as the trailer will be stored in the next week or so. I am probably going to look into the tire's as my problem. It seems that there have been several people that have had similar issues and the tires seem to be the problem. I have been looking for LT tires with a D load rating and it seems that most of the ones I've looked at are all Terrain. I don't do much if any off road and really want a decent all season tire that isn't to aggressive because I want a quiet tire for my normal everyday driving.

My tires and many other 1/2 ton pickup tires, have no letter prefix in front of the tire size. As per this link, my Bridgestone Dueler tires
are passenger tires built to the European Standards. What I've found is that most of the tire manufacturers list my 275/55R20 size tire, as Light Truck, even though the tire doesn't have the LT designation. This can be really confusing for people wanting to buy a true "LT" tire, which are usually designated for 3/4 and 1 ton pickups. I am attaching following links to further describe the difference for those that might not know. The next 3 links explain the different tire types and specifications.

https://www.discounttire.com/learn/r...-tire-sidewall

https://www.discounttire.com/learn/e...-pmetric-tires

https://www.discounttire.com/learn/l...nge-load-index
__________________

__________________
RRS2670 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Capilarry bulb thermostat for old truck camper furnace, pic inside UPbuilder Wanted 7 09-27-2013 08:46 PM
Old Sunline Truck Camper JTurner Classifieds Archive 5 10-23-2012 08:18 PM
Tires /Trailer Sway apackoftwo Repairs and Maintenance 22 06-25-2012 04:32 PM
Trailer sway bar and leveler ed_wilson475 Repairs and Maintenance 10 08-24-2010 08:57 PM
To Sway or Not To Sway? murc Towing and Tow Vehicles 11 04-05-2007 09:41 PM


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Sunline RV or any of its affiliates. This is an independent, unofficial site.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:57 AM.


×