Axle flip

[MikeW]

Got my other kit today. Have everything in hand to do the job. Trailer comes home two Sundays from now and the following week I will dig into it. What does have me curious is why the axles are designed with a drop in them? Most axles I have ever seen or just straight axle to the spindles. But the axles on my trailer have a few inches of drop from the spindles to the actual tube. I wonder why that is?

[vcrt]

Good question Mike, I'd like to know that too. Seems that we are adding this flip kit to bring the spindle to about the point it could have been had a straight axle been used in the first place. Not only that, but it would make brake adjustments a whole lot easier as that dropped spindle is always in the way of the brake adjuster tool.

Anyway, isn't a straight axle stronger than a dropped axle? Must be a reason I'm not aware of.

Rich

[MikeW]

Originally Posted by vcrt

good question mike, i'd like to know that too. Seems that we are adding this flip kit to bring the spindle to about the point it could have been had a straight axle been used in the first place. Not only that, but it would make brake adjustments a whole lot easier as that dropped spindle is always in the way of the brake adjuster tool.

Anyway, isn't a straight axle stronger than a dropped axle? Must be a reason i'm not aware of.

Rich

exactly my thoughts!

[JohnB]

The drop axle is an option Dexter and other axle mfg'ers offer. This allows the trailer to be lower then the straight axle.

Now to why did Sunline pick that option? Here is a guess. Sunline made most all of their travel trailers as lower riding trailers. Even the larger slide campers are lower then the most of the industry and they have straight axles. Our big camper has a straight axle but is still lower then many of the other brands. Our tire to wheel well bump clearance is less then the industry norm. Sunline at 2.5" and the rest of many other brands is at 3" and more. And our springs are on the bottom of the axle tube where many other brands with higher campers have the springs on top. Basically non flipped springs.

I believe they set up the TT line as being lower to help reduce towing wind drag, create a slightly lower center of gravity and less steps to get in the camper.

As to is the straight axle stronger then the drop axle, well they engineered the drop axle to meet the same ratings as the straight axle. A 3,600# straight axle holds the same loads as a 3,600# drop axle. They may have had to beef up the drop section to meet it. From an axle manufacturing standpoint, the drop axle costs may more to make. There is more steel on the drop axle stub, a little bit more difficult to machine and then a little more difficult to weld the left and right side in sync with the other side.

Those are my 2 cents on the topic. What ever the reason, they carried it across the line of campers from way back when until the last 2007 models. They made the campers lower on purpose.

John

[MikeW]

Well let me tell you the reasoning for my interest in doing the over/under swap. The number one reason is that with the trailer being so low to the ground that my grey and black water tank drain valve is so low to the ground that I almost always have an uphill run to either my portable tank or a sewer hookup at a campground. I need to get that valve higher off the ground to eliminate that issue. My fluids should not have to run uphill to drain from the tank. I have not had any dragging, parking or towing issues in its current factory condition. But the drain issue is my #1 reasoning for doing the axle flip procedure.

[JohnB]

When we had our T2499, there were times at full hook up campsites I had to back the camper up on 2 x 8 boards on both sides of the camper to raise the camper high enough to allow the dump pipe to be higher then the dump hole at the campsite...

It seems in the state of Ohio, there is a regulation the dump hole needs to be 6" above grade to pass inspection. Something about concerns over ground water getting into the sewer system. Well that 6" is a real problem on an under slung axle camper. The good news or the reality of this, a lot of folks had issues with this 6" high dump pipe too. So some were trimmed by the CG later after the inspections where done. But not all so I always carried enough lumber with me to raise the camper up.

[vcrt]

We stay at state parks almost exclusively and there's no sewer pipe issues because most don't have full hookups. (Some don't even have electric.)

Our concern is scraping the back end of the camper when the road surface is uneven like coming out of a gas station. Last year, we stayed at Cowans Gap SP in PA and even though we'd been there before, it was dark when we arrived and I missed the turnoff for the entrance. That brought us on a narrow road where we looked for a turn around place. After about 2 or 3 miles, I found something and pulled in. But when I started to back up, sssscccrrraaaaappe!
I got out and found that the pitch of the road had our trailer wheels in the low spot at the edge of the road and the bumper was laying right on the high center of the road. Well, with some back and forth action, we were able to get it turned around, but that's just the kind of situation that arises suddenly and can cause some real headaches with a low-slung camper.

I agree that a lower camper gives all the benefits you listed John, and that's why I've hesitated to do the axle flip, but I haven't heard one negative from others who have done it concerning towability.

I am always amazed at the height I see on many of these newer campers though, they look so unstable to me.
Rich

[Jtrobbins13]

Originally Posted by vcrt

I am always amazed at the height I see on many of these newer campers though, they look so unstable to me.
Rich

We were just camping this past weekend with friends of ours who just bought a 2017 Keystone 32 footer which sits really high... The sights we were on had a pretty good slope from front to back so he had to use 6 blocks and extend his rear stabilizers near fully extended... Didn't matter how soft you walked in his camper you could feel it move with every step you took... I only had to use 2 blocks and I could have done jumping jacks in our Sunny (except I am 6'2" and just barely miss hitting my head on the ceiling as it is, lol) and you wouldn't have felt a single wobble or anything...

[vcrt]

That is a concern also jt, I've seen folks at campsites with a stack of lumber under their jacks because of a slope.

You know what would work perfectly? Hydraulics, like they use on the lowriders! You'd keep it at stock height for fuel-efficient towing and when you encountered a rough road or one that had a sharp slope, push a button and swoosh! instant clearance.
I do think it would be pricey though. Although an economical alternative would certainly be something I'd be interested in.
Rich

[johnnybgood]

Originally Posted by Jtrobbins13

We were just camping this past weekend with friends of ours who just bought a 2017 Keystone 32 footer which sits really high... The sights we were on had a pretty good slope from front to back so he had to use 6 blocks and extend his rear stabilizers near fully extended... Didn't matter how soft you walked in his camper you could feel it move with every step you took...

I'm not surprised. My daughter and son-in-law have a 2017, 39 ft Keystone Bullet and and that thing's like being in a boat. It's no wonder as the stabilizer jacks aren't mounted directly to the frame. They're mounted to flimsy L brackets that are mounted to the frame.

[mainah]

I watch these huge 5th wheels go down the road the top of the camper towering over the one ton trucks easily twice the height talk about wind drag than once parked it's like 4 steps up into the camper! It's no wonder they flex.

[Tkch88]

Ive been considering raising my trailer since I've owned it. My back guards were bent and mangled the first year. But I've learned to live with the low clearance. My main issue is the low pitch sewer tank on my 2470. I have to use a wand and hose to clean it out thoroughly. I avoid non-sewer sites as cleaning at a dump station might take too long. So I've considered raising the trailer to put in a better tank. Has anyone done that?

[JohnB]

Originally Posted by Tkch88

Ive been considering raising my trailer since I've owned it. My back guards were bent and mangled the first year. But I've learned to live with the low clearance. My main issue is the low pitch sewer tank on my 2470. I have to use a wand and hose to clean it out thoroughly. I avoid non-sewer sites as cleaning at a dump station might take too long. So I've considered raising the trailer to put in a better tank. Has anyone done that?

Hi,

Can you explain some on what you mean by a better tank? Trying to figure out what your thoughts are for being better. Larger capacity, easier draining etc. Do you mean both the black and gray?

Thanks

John

[MikeW]

Trailer is home from our summer spot. A full cleaning in the next couple days and then the task at hand of installing the axle kit. My issue now, after having my mind completely made up for weeks is that a friend and fellow camper suggested NOT doing the job until after our trip to upstate NY in 3 weeks. He fears I will have issues and will surely rear it's ugly head on my longest tow of the year. While I am not so easily intimidated myself, can I ask your opinions on this theory? Again, I don't forsee any issues but he does have my wheels turning with his thoughts on this. Someone please keep me on my path and assure me that I am correct in my thinking all will go smoothly. What could go wrong?
LOL

[Tkch88]

By a "better tank", I mean one with a larger pitch (more slope) to the drain. Gravity only does so much for me. When I proceed to rinse it with a hose and wand, I see many solids continue to flow out. One think I now do that helps is use a small jack to raise the opposite side, at dump time.

Dave

[JohnB]

Originally Posted by MikeW

While I am not so easily intimidated myself, can I ask your opinions on this theory? Again, I don't forsee any issues but he does have my wheels turning with his thoughts on this. Someone please keep me on my path and assure me that I am correct in my thinking all will go smoothly. What could go wrong?
LOL

Hi Mike,

The axle flip is a somewhat straight forward mechanical change. That said there are some things you could run into that will take an amount of time to ring out. I do not know your time line but here are some things to think through. You will have to make your decision to wait or not. If you have gone this long with the original setup, will it hurt to leave it for one more trip? And on the other side of this, it would be great to have the added clearance for this trip.

Regardless of how well the install goes, you should take it for a test tow to make sure everything works right in enough advance to allow time to correct something. Here are a few things that might crop up.

1. Rusted bolts. They are almost a given, do you have the equipment to deal with them being frozen on? One badly frozen on bolt can turn a few minutes into many hours.

2. All new U bolts and nuts, do you have them?

3. There is a pilot pin in the middle of the spring pack that pilots in the axle seat. This helps align the spring pack to the axle seat before you tighten up the U bolts and an added safety to keep it from slipping out of location. If the nut on that pin is solid rust, find some spares before you start. You really need them in there. If the head pops off trying to get it out, it needs to be replaced.

4. Brake wiring. I think your camper is a 1996 model, right? That is a nice 21 year old camper. If you are still running on the original axles and the original wiring for the brakes, odds exist when you disturb that older wiring you may create a insulation gap/crack that rears it's ugly head as a short and one or more brakes stop working.

It is a camper text book failure to have the double wire inside the axle tube that crosses over from the left to right side that the insulation becomes brittle, cracks and or chaffs through it from bouncing down the road and creates a short. To get out of that ordeal, install new wire but on the outside of the tube or better, run a new brake hot and ground wire direct from the front of the camper down each side of the camper to the front axle brake and rear axle brake. Again do this on each side of the camper and not cross over on the axle tube.

5. When was the last time you had the brake drums off to check the brakes? If this was not so long ago, then great. If it was a real long time ago, you may find some brake issues that need to be addressed while you are working on the axle flip.

All the above are some of the larger things that pop up in my head thinking on this quick like. All are very fixable, they just take time. This comes back to the time factor. Do you have the time to deal with them if they come up?

Hope this helps and have a great trip.

John

[JohnB]

Originally Posted by Tkch88

By a "better tank", I mean one with a larger pitch (more slope) to the drain. Gravity only does so much for me. When I proceed to rinse it with a hose and wand, I see many solids continue to flow out. One think I now do that helps is use a small jack to raise the opposite side, at dump time.

Dave

Hi Dave,

OK got it now and understand the issue. While I do not know of someone doing a tank change on the dump port, I may have a few ideas to help the solids flow issue.

On our first Sunline, a 2004 T-2499 it had a somewhat wedge shaped bottom. Means it had a fairly good down hill angle to the dump valve. Stuff naturally wanted to flow down hill.

On our second Sunline, our current 2004 T310SR, I have one of the unique enclosed tank setups on a Sunline travel trailer. While the 5th wheels had them, mine may be one of the few that ever had an enclosed and heated tank compartment on a TT. These tanks are very flat due to the enclosed tank setup. The dump valve is right on the end of the tank outlet up inside the tank compartment. Then a 90 deg elbow on the dump valve and a 3 to 4 foot pipe to the dump port you put the hose on without a lot of down hill slope.

This black tank setup just plain drains slow as molasses in January.... and as such solids and paper do not want to leave on their own. To combat this, I added 2, rotary tank sprayers inside the black tank. Also put 1 in the gray tank. This made a world of difference. It allows me to flush the tank out well. I can close the dump valve with the sprayers running and it will fill water in the tank and help float solids and paper in the corners to the outlet. For sure you do not run the sprayers with the dump valve closed and walk away, but having them run for 2 to 3 minutes is not a problem on my larger tank size. I'm only putting in approx 5 gpm if that. Doing the fill and flush really helps it run clean and I do not have to pull the hose wand tank wand inside.

And yes, I either go early or later to the dump station to not hold up the dump line on a Sunday leaving camp when everyone else is. If I do have to dump and run as there is a line, I dump quick and then at home I have a sewer outlet to my septic system I can flush and clean up with.

See here for the Camco rotary sprayers on my T310SR. I used a straight non rotate flush nozzle on the T2499 even though it had a good sloped tank. After having the sprayers in a tank, I will not go back to not having them on a camper. They help me clean up really good. http://www.sunlineclub.com/forums/f6...pics-9496.html

Hope this helps

John

[MikeW]

Originally Posted by JohnB

Hi Mike,

The axle flip is a somewhat straight forward mechanical change. That said there are some things you could run into that will take an amount of time to ring out. I do not know your time line but here are some things to think through. You will have to make your decision to wait or not. If you have gone this long with the original setup, will it hurt to leave it for one more trip? And on the other side of this, it would be great to have the added clearance for this trip.

Regardless of how well the install goes, you should take it for a test tow to make sure everything works right in enough advance to allow time to correct something. Here are a few things that might crop up.

1. Rusted bolts. They are almost a given, do you have the equipment to deal with them being frozen on? One badly frozen on bolt can turn a few minutes into many hours.

2. All new U bolts and nuts, do you have them?

3. There is a pilot pin in the middle of the spring pack that pilots in the axle seat. This helps align the spring pack to the axle seat before you tighten up the U bolts and an added safety to keep it from slipping out of location. If the nut on that pin is solid rust, find some spares before you start. You really need them in there. If the head pops off trying to get it out, it needs to be replaced.

4. Brake wiring. I think your camper is a 1996 model, right? That is a nice 21 year old camper. If you are still running on the original axles and the original wiring for the brakes, odds exist when you disturb that older wiring you may create a insulation gap/crack that rears it's ugly head as a short and one or more brakes stop working.

It is a camper text book failure to have the double wire inside the axle tube that crosses over from the left to right side that the insulation becomes brittle, cracks and or chaffs through it from bouncing down the road and creates a short. To get out of that ordeal, install new wire but on the outside of the tube or better, run a new brake hot and ground wire direct from the front of the camper down each side of the camper to the front axle brake and rear axle brake. Again do this on each side of the camper and not cross over on the axle tube.

5. When was the last time you had the brake drums off to check the brakes? If this was not so long ago, then great. If it was a real long time ago, you may find some brake issues that need to be addressed while you are working on the axle flip.

All the above are some of the larger things that pop up in my head thinking on this quick like. All are very fixable, they just take time. This comes back to the time factor. Do you have the time to deal with them if they come up?

Hope this helps and have a great trip.

John

Thanks John. As I mentioned before I am a mechanic by trade and our family has our own repair, towing, body shop facility. Any issues mentioned above that can pop up are easily fixed or replaced with in stock items (wiring, frozen bolts, etc). Brakes have not been checked since I took ownership 2 years ago but I bought it from a long time friend and I am aware of his maintenance practices. He cared for it well. If brake systems are an issue I already am prepared to just replace them all with new bolt on fully equipped backing plates. Simple and quick fix if needed. We have a local trailer service center we do biz with and they stock parts if needed. Bearings will be repacked during the flip process. I trust all will go fairly easy and I am well prepared with the Dexter axle under/over kits and research that has been done. Thanks for the time and tips. To me it seems easy. We shall see. Tomorrow after work the progect begins. GIT ER DONE!

[JohnB]

Hi Mike,

Thanks for the note. Sorry, I forgot you were an auto mechanic. There is no rocket science in this camper axle setup. Think 1950 to late 1960 auto setup with drum brakes. Actually they where better then these trailer brakes... While a bugger of a bolt may flare up, it is no match for a 4 1/2" grinder with a cut off wheel on it.

Good luck and let us know how it goes.

John

[MikeW]

FLIP IS FINISHED!
Still have to rewire the brakes and pull the hubs for inspection but all went perfectly. So glad I got the Dexter kits with all new hardware. Tack welded the new saddles in place. Got about 5 more inches of clearance now!