Why does it tow so well?

[jsms264]

Hey Hutch!

Thank you for the link to your post and info on the CAT scale. Great detail to tell me how to properly weigh the entire set-up. While reading your weigh post I saw a mention that you too are an engineer? I guess that explains all the great detail and information, Thank you!

Off the subject, but much more exciting...how about this weather in Rochester....won't be long now and we'll be able to hook up and go!

[PTHutch]

Originally Posted by henryj

... Another thing I'm working on is the slight attraction a tt feels for passing semis. I think ours is stable enough--some semis don't affect it at all--but the shape, size and speed of the semi does make a difference. I think the presence or absence of cross winds also plays into this. Does anyone have a magic bullet here, or is this something we all live with to a certain extent when we drive 60 mph on just about any Interstate in the country?

Hi Henry

I addressed the semi pull & push by getting a Hensley hitch.

Ya, I know this is extreme and I’m not recommending you or anyone else to go out and buy a Hensley hitch.

Just sharing that in my specific situation, the Hensley has totally eliminated all pull & push from semis passing me when driving on expressways regardless of the semi's size/shape, the wind, or speed.

Hutch

[PTHutch]

Joe,

You're welcome, glade it was of some help to you.

Originally Posted by jsms264

Off the subject, but much more exciting...how about this weather in Rochester....won't be long now and we'll be able to hook up and go!

I definitely have the itch to get out, but don't hold your breath - I hear it's supposed to snow this week-end. I was planning on de-winterizing the trailer this Saturday, but with what’s forecasted, I think I’ll wait a week.
That's Rochester / WNY weather for you.

Hutch

[henryj]

Interesting that a Hensley cures that. One of the dealers we shopped at was an Airstream dealer and they seem to sell a lot of Hensleys. Pullrite also makes an interesting tt hitch that is like a swinging drawbar on a tractor--it's also mounted close to the rear axle so is supposed to be very stable like a 5th wheel. I've always kept my eye out for one, but have never seen one. Now I can't even get onto Pullrite's website. Did they go broke too?

Henry

[PTHutch]

Originally Posted by henryj

... Pullrite also makes an interesting tt hitch that is like a swinging drawbar on a tractor--it's also mounted close to the rear axle so is supposed to be very stable like a 5th wheel. I've always kept my eye out for one, but have never seen one. ...

Hi Henry

I've also heard the same thing of the Pullrite hitch.
And like you, I have keep my eye for someone that has one just to talk to them about it, but have never come across an individual that has it.

Hutch

[larry818]

Years ago I had that idea, after a nasty fishtailing experience with a car trailer. I went and designed it up, and only then checked to see if anyone else was making them. I found, pretty quickly, three companies already selling them.

I've never seen one in the wild either.

[henryj]

Pullrite's website must have been down yesterday. Here's a link to their tt hitch:
http://pullrite.com/pullrite.htm

It's a really good looking concept, but not cheap either, although less than the Hensley. You can find lots of people who'll endorse a Hensley, but I would be reluctant to spend this kind of money without talking to someone who had used this hitch.

If anyone is interested in this concept, here's a good link to a personal page with excellent photos and he also points out some of the disadvantages.
http://www.serenitysys.com/rv/techni...ite_hitch.html

Henry

[Mooney]

The vacuum effect of bigger vehicles is even felt when driving one.

That's one of the reasons you'll often see commercial drivers pull WAY to the side of their respective lanes to maximize the gap between them, minimizing the pull.

It's not often, yet not unheard of, to have two trailers nearly get sucked into one another (especially wiggle wagons (double trailers)).

A great way to score big points with us big-rig guys (not in my off-time, but my job...23 feet of coach isn't that big) is to pull toward the side of your lane when you see us coming up. If we know what we're doing, we'll repay the favor 99% of the time (as long as it's safe).

[JohnB]

Originally Posted by jsms264

John,

OMG, wow! Thank you, I am humbled by the amount of information, you are amazing! Did you say your an engineer! I never have put that much thought into the whole set-up, this post and your response in particular has been eye opening. You asked what tires I have on my TV, they are Goodyear Wrangler pro series load range E, 16".

One more question...I promise! Where do folks go to weight their set-up, in particular some place that will let you spend that much time getting all the weights?

Joe

Thanks. No problem and hope it helped. A number of years ago I bought my 1st WD hitch with the TT thru the dealer. The dealer never went into very much if anything about it. I even asked are there instructions with these things? Nope. They have been selling Reese for 25 years and never had any. They stock all the hitch in parts and they bolt them together as needed. The only hitch talk I got was, well if you want more weight moved up front, take up a link. That was it. And they where as sincere as can be. They really did not know any more and at that time I did not know better either.

So after more time went by and I started digging into the camper and the truck, h’mm this does not add up. And the more I dug the worse it got. So I set out to educate myself calling the manufacture direct, writing them letters on my issues and even Sunline at the time. What I found out is, no one ever really takes the time to explain this simple thing called a WD hitch, and what is all going on with this thing that has 3 main parts. A hitch head and 2 WD bars. How mysterious can it be?? And then there is the one set of instructions that is suppose to fit every TV/TT ever made.

Also doing more digging I found out there are a lot of good folks who really had no idea either and the many of them where dealers. The dealers do not want to or can’t afford to, take the time to optimize a WD hitch setup for every TV/TT combination. If they are charging $65 to $80/hr and selling a $450 hitch, well it does not take many hours to ever run up a very high % of the price of the hitch in labor and how do they explain that to a customer. Plus the rig is not loaded ready to go camping and the adjustments are wrong when you go to use it.

Some times a rig will dial right in quick. Maybe 30 minutes of fiddling in the exact right spot. And the owner was fortunate and never realized why it came in so easy, so why are you having such a hard time?? Other times you have to work at it as the 1 size fits all instructions do not always yield the same results across every TV/TT combo.

And then there is the miss-information about your exact setup. What works for one person does not always work for the next. And then there is, well everyone gets a little wiggle when semis pass? Right? No not really. And when you ask deeper they are talking about having to do steering corrections every time a semi passes, the rig is not setup right. They are on the edge of a sway event and have just been lucky enough to not get in a bad situation yet. Sway is not normal. Most can be corrected thru optimizing the hitch setup, some need a few things upgraded along the way and then there are limits that are pushed that can’t made up for and an TV upgrade may be in the works or a smaller TT.

So along the way a I have made number of new friends helping them with there setup and the continued learning each time. Once someone explains this to them, they most times they can help themselves.

I see you are coming to the M & G in June. I’m putting on a Hitch talk to help explain about WD hitches, TV setups and sway controls on how to optimize what you have from my learnings. Sort of a campfire talk on hitches. Again taking the time to explain what you want to end up with. And I see you are 2 campsites away from us. Come on over and we can do some one on one as needed after or before. A number of people have helped me, so I return the favor when ever I can.

To weighing your rig, you have some good replies, dead on. I’ll add a few things.

I have used both the Cat scales at Pilot and other truck stops and also the scales at Flying J trucks stops.

Before doing a TV/TT weighing, go inside and talk the manager. Explain to them you want to weigh your TT and TV all axle by axle and it is going to take at least 3 weight slips to accomplish most of this to determine if your WD hitch is set up right.

If you have a set of walkie talkies, bring them. Give one to the scale person inside and explain to them what you are doing and you will call them when your are ready to approach the scale. And then tell them to take a reading and they tell you back they got it and not waiting on a customer inside and just missed it. Basically communication is king in the frustration factor here.

Know your TV and TT license plate tag. They are going to ask for your truck and trailer numbers. Tell them this is a private sale and give them the truck and trailer tag numbers. This way you have a weight slip you can show to a state trooper if needed

At Flying J, they have what they call free re-weighs if you never leave the yard. At Pilot with the Cat scales, it costs about $1 for each reweigh if you never leave the yard. Point is, tell them you are needing to do a reweigh after load adjustments. If not they will charge you full price ~ $8 each scale weigh. I’m sure all places are slightly different, but ask about reweighs and the costs to the manager. The help at the counter may not allways know.

Using truck stop scales. Many truckers make a living by time hauling. And Time to them is money. A semi can scale in and out in less then 3 to 5 minutes. They are not fiddling with a WD hitch, they are after axle and GVW to stay legal for commercial trucking. And as such some times they get a little upset with someone tying up the scales for a long time. (10 minutes) Find the off hours that are less busy. And let the semi’s go first. Most truckers are very respect full and will not give you any problem, just be understanding of their situation.

I have several times spent 2 ½ to 3 hours at a truck scale getting 4 weighings the first time. From time in to time out. But I got my data and all was good. After you do this enough and know the truck loaded weight, making tweaks on others trips is quick. You are then sort of like the semi then, Roll in, get weighed, and on your way. The 1st time is the hardest.

Also, take a tape measure with you and a pad. Write down the truck fender heights before each weighing. See here I use a small piece of electrical tape so I can get a more accurate reading and come back to the same spot. This way when your back home, that height does repeat for a certain weight within reason. You can tweak in your yard and have a good idea on weight. Also measure the TT hitch height with each set of scale numbers/fender height so you know what that was. Just find an easy spot to remember off the frame.





And didn’t worry about asking 1 the last question. Ask away. If I can’t get back to you fast enough, we have a lot of other good folks here that will chime in. If you want I have MS word file I have used with pic’s t help others on how to setup a TT and TV with Reese DC I can email you. PM/email me if you want a copy.

Good luck and hope this helps

John

PS Oh the engineer part. Well I get accused of that at work often. Especially when the production line machinery will not cooperate. Then we really get accused of it…… Darn engineers messed with my line and now it won’t work…. I can hear it now. When it runs great, we are a forgotten bunch.

[JohnB]

Originally Posted by henryj

So, John, my experience is also to return the loaded front height and weight to the unloaded, despite what Equal-i-zer says. I wasn't aware that this was better for a torsion bar front end so that is an added bonus.

Another thing I'm working on is the slight attraction a tt feels for passing semis. I think ours is stable enough--some semis don't affect it at all--but the shape, size and speed of the semi does make a difference. I think the presence or absence of cross winds also plays into this. Does anyone have a magic bullet here, or is this something we all live with to a certain extent when we drive 60 mph on just about any Interstate in the country?

Henry

Henry, Yes I know Equl-I-izer has preached the equal compression message for a long time but has finally changed it’s tune about a year or so ago. They actually changed the directions too. They now at least admit returning to unhitched height is OK and they give an option to go lower if you so chose to. Progress Mfg is a good company and they make a really good hitch. And now they have caught up to the way the newer GM’s and Ford’s recommend you set up your TV for WD.

From page 19 http://www.equalizerhitch.com/pdf/eq...structions.pdf

“IDEAL ADJUSTMENT:
There is no way to call any one setup correct as weights are constantly changing (gas tank full/empty, water tanks, packing habits). The most ideal assumption of correct weight distribution setup is to follow the rule that weight distribution is achieved when fender height measurement (C) approaches original fender height (A)”

The big 3 TV makers have different WD setup requirements and all 3 have different front end suspension. So who do you go by? The company that sells you the $450 hitch or the TV manufacture that sells you the $30K TV? This has been a really confusing topic to many as they read the hitch instructions and feel that should be right. And in many cases they are just fine for the TV, but all TV’s are not created equal. Especially in the ¾ and 1 ton range. Draw-Tite use to the one of the only WD hitch makers that actually admitted in there directions that 3/4 and 1 ton trucks do not have to squat the front end. See page 4. http://www.bsaohio.com/instructs/N7901.pdf

“3/4 - 1 ton and / or long wheelbase vehicles will typically settle with the front wheel opening “F” at the original dimension to 1/2” higher than original. This is will still allow acceptable front wheel loads, good handling and the desired load on the rear axle and trailer axle.”

Reese sort of leaves it open for a lot of interoperation. http://www.reeseprod.com/fitguides/pdf/N66022.pdf Page 3. They state TV should settle evenly or within a 1/2”. ??? Getting a Chevy 3/4 ton year 2000 or newer to settle evenly is not an easy or doable task.

OK so what does GM say about all this? Well I had a 2003 K2500 Suburban. And in 2003 they did not say a lot about WD in the owners manual. I have a 38 page post on RV.net a number of years ago when many kept telling me I had to get equal squat front and rear. So I tried to get it and could not. And finally we proved why. The Torsion bar front end suspension does not like it when it get’s over compressed from normal ride height. You can actually crack your jounce bumpers if you run that way long enough.

So what’s a jounce bumper…. Well if you crawl under your truck look for this yellow bumper stop on the lower control arm.

This is what is looks like “unhitched”


Now here it is with TT tongue weight of 1,200# dead weight, no WD engaged.


And now once I engaged WD and returned the front end to unhitched height. Looks like unhitched.


The GM’s like to ride around at there normal spec ride height. They call it Z trim height. See here, I measured mine and had to tweak it into spec, then go get it aligned.


And a rear view


If you use WD to over compress the front end, that jounce bumper get’s over compressed. And then when the truck takrs a nose dip while towing, it really get’s strained. The truck also feels stiff as the springs are not working like normal as they are fighting the jounce bumper. This however will only last so long as you can crack the bumper I have seen these cracked in half on PU’s but never rode in one when it was.

THEN in 2004,. GM added this page to all PU and SUV owners manuals. My 2003 never had that.


That pic is from my brothers 2005 Silverado manual. That page should be in your 2007 Serria manual too. So GM came right out and said for WD to only return the TV to unhitched height. If that page had existed in the 2003 manual it would of save me a ton of posting on RV net trying to convince the older school WD setup masters that the new TV’s don’t like there front ends over compressed. However if it ws there, I would not of learned so much about setting up WD. So it was a good thing to talk about this.

Since you did what Equal-I-zer told you on the older setup rules, and found that you ride better at unhitched height, you have just revalidated the findings. I could not get mine to drop so I could not even test riding around 1/2" or more compressed.

Now to your questions about semi’s passing and you feeling it. Need more descriptions here to what you are feeling. A wiggle or rocking motion or do you have to do steering corrections and it feels liek the back of the truck is wagging around left to right?

Also what brand and size tires are on the front and rear and what air pressure do you run towing?

Hope this helps

John

[henryj]

Originally Posted by JohnB

Now to your questions about semi’s passing and you feeling it. Need more descriptions here to what you are feeling. A wiggle or rocking motion or do you have to do steering corrections and it feels liek the back of the truck is wagging around left to right?

Also what brand and size tires are on the front and rear and what air pressure do you run towing?

Hope this helps

John

The feeling is much like driving in a crosswind and having to make minor steering corrections when entering and leaving sheltered areas like underpasses. I get a smaller version when driving my car, and maybe, as Mooney said--don't crowd the center line when a semi is coming up is the solution.

I still have the factory Bridgestones--LT245/75R16--which I run between 45 and 50 psi on the front and 65-70 on the rear.

Henry

[JohnB]

Originally Posted by henryj

The feeling is much like driving in a crosswind and having to make minor steering corrections when entering and leaving sheltered areas like underpasses. I get a smaller version when driving my car, and maybe, as Mooney said--don't crowd the center line when a semi is coming up is the solution.

I still have the factory Bridgestones--LT245/75R16--which I run between 45 and 50 psi on the front and 65-70 on the rear.

Henry

Henry,

The push/suck of a large mass is there, however something in your post sticks out that you might be able to help.

You said cross winds do this too, which tells me you there is a slight instability still in your rig setup that you may be able to help. As a point of reference, Flags fly striaght in a 30 mph wind. Look at the flags around when towing to get a feel for the wind spped. This is out of the Boy Scout Field book and I have used it many times.

I’ll ask first to see if these areas are optimized.

TV WD on the front axle. I’m assuming the WD is set so the front fenders are returned to unhitched height when fully loaded. You said this before, just checking.

On the Equal-I-zer, are the trunnion sockets where the WD bars fit into torqued to the spec? 45 to 60 ft lbs? On this hitch, this is part of the sway control action by being tight.

On the Equal-I-zer L brackets, are you running grease or using the plastic pads they provide? While grease and the pads lower the noise in turns, it also reduces the anti sway.

Knowing you have a T2499, just confirming you are in the 13 to more then likely 15% tongue weight per loaded GVW range?

TT towing height level or slight nose down?

I’m pretty sure the above are all in line but just asking to check as the next one may be your issue if all the top are right.

Tire pressure. The LT245/75R16 are 80 psi tires correct? That was what my 2500 Suburban had.

Try this. On rear, use max cold side wall pressure: 80 PSI.

The front, here is going to be an experiment. You said you go 45 to 50. 5 psi can be a lot when you are on the edge. Start at 55 psi. Try it. If the front end does not seems like it is bouncing, go to 60 psi. Feel and then try 65 psi. Most likely 70 psi you will start to feel a bouncing wander, 75 psi might be jsut as bad. but 60 to 65 psi most likely will work on that suspension/ wheel base

In your case the tire pressure can be/might be a global shift to being more stable. I know you have LT tires, but all LT tires are not created equal. They can still be semi soggy at the lower pressures as they are built for 80 psi. And that soggy can create this effect:

On a cross wind, the Equal-I-zer is holding the TT/TV connection stiff. The truck and TT are stable up to the point the hitch can’t hold it any more. The wind gust hits the front of the TT hard, if the tires on the truck have flex to them, especially the front, the front of the truck will kick slightly. Actually the tire is flexing on the rim in the side wall and slightly giving way. The tire is still on road but flexed in the side wall. Once the tires give way from side flex, the hitch has to flex in the trunnion sockets and L bracket area as it can’t hold the rig because the front of the truck moved. In the truck driver seat it feels like the back end of the truck took a twitch/shift to the left or right pending the wind just, but really it is the front end shifting left to right. And you do slight steering correction because of it.

If the wind gust is doing this, the semi will have issues most likely too. It is amazing what tires and side wall flex can do. I first hand experienced this on my K2500 the first time I put new Michelin LTX tires on. It was so bad that Cindy said, wow, what was that!!. On those LT 245/75R16’s it took 60 psi to stop it. I ran 65 psi to give me extra saftey cushion. On my older Steel Tex, they where a stiffer tire and I could run 50 psi. On the Michelin, I could never think about towing at 45 psi. My goodness no. It would be like going back to P rated tires. Your Bridgestone I’m thinking are cushior then my Steel Tex where. And cushy and towing stability do not really go together.

You can also start this tire experiment by doing 80 psi rear, and just leave the rear at 80. Put 70 psi front to start with. Tow with it. If it is too hard, pull over and let just 5 psi from where ever it is out. The heated pressure will be higher, but you will be 5 psi lower then the initial reading. Most likely 70 psi will give you the hard bouncing I was referring to on your wheel base length. I know I have a camping buddy who run LTX at 75 psi on the front of their F250 with a diesel under the hood but on that weight set and longer WB, it is not a problem. Your 6.0 does not weigh as much.

From what you describe and knowing the suspension of your truck and the T2499, I think that will seriously help your problem. Then when semi’s come by, yes do pull to the right close to the white line it will help too.

PS. If the rear is soft, it can do this too. 65 psi can be a problem pending tire brand.

Hope this helps

John

[henryj]

Thanks for the ideas, John. I'll definitely work on the psi. I think everything else you mentioned on my towing setup is as it should be. I do carry a torque wrench mostly for adjusting the wd bar socket bolts, but confess I should do that more often--like every day as it only takes a minute.

Henry

[JohnB]

Hope it helps Henry and I do suspect it will. It was an eye opener for me when I had a rock solid rig on the older OEM Steel Tex, No sawy, semis did not affect me and wind was a non issue. Then I bought premium tires that rode really nice non towing and was a real shocker the first trip out heading west in I 70 west toward Indy. We can get good cross winds there and OMG, while semis still did not affect me, I felt wind gusts non stop. It was truly a global shift to an unstable rig in my opinion. Then after 2nd guessing myself and rechecking everything in the WD and hitch setup, and I thought the Quadrasteer was acting up twitching the rear end so I locked it out and it made no difference.

Then came the tire pressure experiment. I went up 10 psi to 60 on the front. I figured rather then fiddle with 5 psi increment I would try a 10 psi jump and see if it would do anything. WOW. It was like you flipped a switch, it was that noticeable. I almost had my old rig back. Once I was onto that the 5 psi test continued all the way to 75. and then back down to 65 where I towed with it until I traded it.

Non towing I aired them back dowe to 50 front, 65 rear.

Also since this I had 2 other buddies I helped set up their hitches have tires issues. Once was on a Yukon (the shorter one) There he upgraded from P to LT’s but he also found out with BFG’s that even with LT's, you have to run them up in the higher pressures to get stiffness above his P tires. His first trip out was worse then his P tires until he aired them up to create the stiff.

Then I had a buddy I helped with his 2007 ½ ton Suburban. He had an older 2002 Burb he towed with and was fine until he got his new one. Now in his case he had hitched setup issues going from one TV to the next. I helped him fix that but them came the test drive as he was still complaining about the oscillations. The hitch and weights where right, he even was to the scales. So we test drove it and I told him while doing 25 mph, take the wheel and do a small left to right steering action out on the back roads near my place I watched the rig in the mirror. As soon as he did that the whole truck started going left to right along with it. Not good. They changed the tire types on the new style Burbs and they ride like a cream puff non towing. Really nice.

But for towing, cushy ride and towing stability are not really to be used in the same context.

Once you try out the tire experiment, please report back.

Good luck on your trip.

John