New 5th Wheel Rough Ride

[JRHERE]

Could the condition of fresh water tank (full vs empty) allow one to experiment with biased weight to pin?
Assuming forward of axles? Be interesting to try for S&Gs.
Suppose any holding tank forward of axles could be utilized?
Easy to weigh before and after truck drive axle. Get an accurate pin weight.

[Worthmo]

My fresh water tank is in the rear of the camper. I haven't put the camper on the scales yet, but the PIN weight from the factory is 1,428 which is 16% of the dry weight. We have our belongings in the camper. Most are packed away in front of the axles but wouldn't add up to much weight.

[JRHERE]

Originally Posted by Worthmo

My fresh water tank is in the rear of the camper. I haven't put the camper on the scales yet, but the PIN weight from the factory is 1,428 which is 16% of the dry weight. We have our belongings in the camper. Most are packed away in front of the axles but wouldn't add up to much weight.

Interesting place for a large fresh tank? And so I'd assume adding water to an aft tank would add to the problem.
Accurate weights will be interesting.

[Aeross]

Hi Worthmo,

I purchased the exact 5th wheel in May this year and we've had the same issues with severe bouncing. I'm pulling it with a 2020 Ram 3500 with rear air suspension and we camped for 2 months, 4,300 miles and the unit has been in the repair shop for the last 6 weeks fixing all the things that broke loose on our trip (fireplace glass, oven pulling out, countertops pulling away from wall, cable wires disconnected, drawer locks not holding, bunkroom pocket door broke off hinges twice, ceiling fan broke from shaking, etc.).

Out of necessity, we did make some modifications on the road that helped to some degree. The Ram 3500 bed height is high and the front of the RV was higher than the rear so I had a 2 7/8" Torflex lift kit installed on the RV. I wasn't that enthusiastic about adding more height to the 5th wheel but couldn't find any alternative. That improved the drive some, but we still experienced significant bouncing. After reading and getting some advice from another RV forum, I bought 500 lbs. of water and salt and stored under the front bed and front hatch to increase the pin weight. That slightly improved the ride, but only a little. The last change we made was to swap out the hitch. Originally, I was pulling with an Andersen Ultimate Hitch and I replaced it with a much more expensive (and heavy!) Hensley airbag hitch. The Hensley hitch improved the truck ride by isolating us from the RV, but we found that the RV was continuing to be damaged by the bouncing.

So I'm starting to think this may be a design issue with the RV itself. I'm sure the fact that we opted for the 148 lb. washer/dryer that sits against the far back wall of the RV has contributed to the issue along with the bikes we're loading on the hitch. Once the RV gets out of the shop, I'm going to try adding even more weight on the front to see if that helps (from 22% up to 25%). I've also been investigating if there's any way to reduce the bounce (maybe the rebound) in the Torflex suspension, but have been told that these axles aren't engineered to add shocks or supersprings. I've also priced out replacing the axles with spring axles, but not ready to make that move yet on a brand new unit.

So - I'm very eager to hear if you or others on this forum come up with any ideas as we're planning on heading out on another long trip in a couple months and ideally I'd have this issue fixed before we leave.

I did stop by the scales to independently weigh the truck and RV. Here are the numbers (and this was before I added 500 lbs weight to the front):
Truck only: Front Axle: 4,940, Rear Axle: 3,740, Gross: 8,680
Truck & 5er: Front Axle: 5,160, Rear Axle: 5,680, Trailer Axles: 9,800 Gross: 20,640

Thanks,

Anthony

[Worthmo]

Have you tried lowering the air pressure in the tires? I'm going to try that on my next trip out. According to your scale weights and the goodyear chart below I believe the PSI should be around 50. I also noticed that according to your scale weights your pin weight is around 19% which I would think is good.

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

[cc102bob]

I have the exact same unit as the OP and I pull it with a 26 year old truck and basic Reese hitch. I have not experienced any real problems with rough ride. I have one drawer under the dinette that likes to pop open, but no other issues.

Caveats:
1) I am still running the original Castle Rock tires inflated to recommended levels.
2) I haven't traveled great distances, so perhaps I haven't encountered the kinds of roads that cause these kinds of problems.
3) The trailer rides perfectly level behind my truck.
4) I don't have any heavy items in the rear of the trailer when I travel (full fresh water tank, washer/dryer, etc.)

I have towed three different fifth wheels with this truck. The first had standard leaf spring axles and a towed weight of approximately 12K lbs. The second weighed the same, but had torsion axles. When I got that trailer I could immediately tell that it was a much smoother towing experience. I attributed that to the torsion axles. This trailer weighs a couple thousand less than my previous unit and I feel that it tows about the same. I've never thought that it was bad enough to try and do anything to make it better.

[Aeross]

I've been running all the tires at the max pressure of 80. I had questioned tire pressure as well and the majority of the feedback I was given on another Rv Forum is that ST tires should be run at the max to avoid damaging the sidewalls and increasing the internal heat in the tire potentially leading to a blowout.

I'm not a tire expert so am open to ideas. I'll certainly try lowering the pressure to see if that helps. CC102BOB - what pressure have you been running your tires? (I'm assuming you also have the Goodyear Endurance ST tires)

Thanks!

[cc102bob]

Originally Posted by Aeross

I'm not a tire expert so am open to ideas. I'll certainly try lowering the pressure to see if that helps. CC102BOB - what pressure have you been running your tires? (I'm assuming you also have the Goodyear Endurance ST tires)

Thanks!

I still have the Castle Rock tires that came from the factory. Unfortunately, I can't remember exactly what pressure I use. The last time I checked them was Labor Day weekend and for my old mind, that's a looooonnng time ago. I'm pretty sure I run the recommended pressure, I just don't remember what that is.

I will be towing it home from our seasonal campsite this weekend, so another check will be in order.

[Worthmo]

I called Goodyear to aske them about the PSI in the tires and they said they need to be at 80psi. The 80psi is needed for the (E) rating, and the (E) rating is needed for the camper. After that talk I'm not going to change the pressure on my next trip.

[cc102bob]

I don't disagree with listening to the advice you received from GoodYear, but it makes me wonder why they would go through the effort of creating a Load/Inflation chart if they always advise people to run max pressure:



I'm guessing it's because the "E" rating specifies that the tire be able to carry "x" amount of pounds and the only way the tire is safe at that load is when it's inflated to max pressure. If you run less than max inflation, then the tire can no longer carry the load specified to get the "E" rating.

The Load/Inflation chart indicates to me that the tire can be run safely at lower pressures as long as you don't put more weight on the tire than what is indicated in the chart. The trick, I suppose, is to figure out just how much weight you are putting on each tire.

[Bhrava]

Originally Posted by Aeross

Hi Worthmo,

I did stop by the scales to independently weigh the truck and RV. Here are the numbers (and this was before I added 500 lbs weight to the front):
Truck only: Front Axle: 4,940, Rear Axle: 3,740, Gross: 8,680
Truck & 5er: Front Axle: 5,160, Rear Axle: 5,680, Trailer Axles: 9,800 Gross: 20,640

Thanks,

Anthony

I do wonder about your front axle weight. On my F350 hitched and unhitched has no change to the front, but on yours the weight increases 120 pounds. Is that from some added stuff to the cab, or is your hitch a bit forward of the axle?

Your pin weight is roughly 16.5%, which seems a bit light and that can be a potential cause. If you can get it closer to 18%, I wonder if that will reduce some of the bouncing. I know when I brought mine home the first time it was light on the pin, just under 16% and it bounced around a bit, which is uncomfortable being it is 43' long, but once I got it wet and ready it was up around 18.3% and it smoothed out a lot. Now it doesn't bounce, but does let me know I need new shocks on the truck as it woopidy doos, and makes the truck seesaw, at least that is how it feels, but everything inside the trailer stays put, and it has basic sprung axles with no cushioning.

[kirkp]

Originally Posted by DieselDrax

80psi is the pressure needed for MAX load, it is not the recommended pressure unless that is the pressure listed on the trailer's tire placard. What I asked is if the tire pressure is higher than what is listed on the trailer's tire placard. If the trailer has a relatively high CCC and the trailer hasn't been loaded with much then running with the tires at sidewall pressure unnecessarily will contribute to a harsh ride. Just like if you ran the tires in your truck at sidewall pressure with little to no load.

For trailers you should be running them at the pressure shown on the tire. You should not be lowering the pressure to “match” them with the trailer weight (aka under inflation “Doing so will contribute to flexing of the sidewall and increase heat contributing to tire failure. These two items are the biggest problems with trailer tires failing.

[DieselDrax]

Originally Posted by kirkp

For trailers you should be running them at the pressure shown on the tire. You should not be lowering the pressure to “match” them with the trailer weight (aka under inflation “Doing so will contribute to flexing of the sidewall and increase heat contributing to tire failure. These two items are the biggest problems with trailer tires failing.

Patently false, the tire sidewall pressure is not the recommended tire pressure for all loads. You’ll find no tire manufacturer that says this, either, and is why they produce tire inflation charts. Running tires at the pressure needed for a a given load is 100% safe and will not cause tire failure. Please stop spreading misinformation.

[B and B]

We had a Rockwood 8289WS. It bounced all over the road whether a F 15O towed it or a F 250. I found a full water tank helped.When the trailer was fully loaded to max capacity it settled down more. Adding shocks helps a lot!

[JRHERE]

Anyone pulling the above trailer with a 1 ton dually?
How does it feel?
Could be some harmonic with SRW between the truck and trailer are allowing the bucking.
If not, the trailer suspension becomes suspect.
Once owned a 5ver. Pulled it with SRW F-350. On some older roads, the truck and trailer would try to destroy each other. Louisiana and Texas had old tar seam concrete that encouraged bucking. . Had to drive below 50 to stop the bucking. The problem was resolved with the new CC long box dually 350. Maybe wheelbase? Weight of diesel in front? Dunno.
Some recent years Chevy 2500s are known to be less stable tow trucks compared to Ford and Ram. And Ram's new 2500 air ride isn't exactly a gift to towing large either. I sold a nice K2500_6.0 due to loose feeling when towing my toy hauler. Moved the trailer great, but not in a straight line. Bumps such as bridges on interstates would pucker your bum. Bought a Ram 3500 and what a difference two more tires make. A pleasure to travel again. I'm sure any diesel or gasser dually would do the same.
Part of my Chevy problem was the 1200 lb tongue weight. Still, had air and good tight suspension.
I'd definitely try a bigger truck if for no other reason, to rule out your 2500. Borrow or steal a long CC dually for S&Gs.
With the tall trailer box, unlikely the trailer is flexing. The torsiflex axles could well be the culprit. If it bounces behind a dually, the trailer suspension is incorrectly designed. Or incorrectly matched to the load.

[GmaB]

We purchased a 2019 31ft Rockwood Ultralight Signature. I hated it. 5er was beautiful but I couldn’t stand the bucking with every bump. We also purchased an Anderson Ultimate hitch. We pull with a F-350 flatbed with a recessed ball. The Anderson hitch has been the best hitch we’ve ever had. I sure hope you can resolve the problem and can enjoy your adventures.

[jadatis]

Originally Posted by Worthmo

Have you tried lowering the air pressure in the tires? I'm going to try that on my next trip out. According to your scale weights and the goodyear chart below I believe the PSI should be around 50. I also noticed that according to your scale weights your pin weight is around 19% which I would think is good.

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

As long as you did not weigh, we will have to use the GVWR and GAWR'S and number of axles.
If you give me that together with the tirespecifications, I will calculate a highest pressure for that,with no bumping( as far as tiresepressure is the cource. It will be higher then the 50 psi you read from the lists, but lower then 80 psi. My prediction is 65 to 70 psi, lets see if I am right.

Weighing is always better, but mayby in this case it will give the explanation of the bumping.

Also in Europe, where I live, for TT's maximum of tire is standard recomended, but to laws of nature not always needed.

Sometimes even higher then "maximum pressure", wich is in fact the reference-pressure.

Continental-group tyres in Europe often give maximum pressure of 10 psi higher then reference-pressure , so both on sidewall. Not important here, yust " nice to know" information.

[brewnut44]

Pull the tires, Pull the drums, look at the brakes, bearings, torsion equalizers, leaf springs & shackles balanced all tires. As stated make sure the 5er is level when hooked up to your truck, hitch adjustment required? With the above understood and as stated Prior a 5er will ride way smoother then any bumper tow, period.

[DieselDrax]

Originally Posted by brewnut44

Pull the tires, Pull the drums, look at the brakes, bearings, torsion equalizers, leaf springs & shackles balanced all tires. As stated make sure the 5er is level when hooked up to your truck, hitch adjustment required? With the above understood and as stated Prior a 5er will ride way smoother then any bumper tow, period.

Pretty sure the OP’s trailer doesn’t have equalizers, leaf springs, or shackles as they said in their first post that it has torsion axles.

It’s also a brand new trailer under warranty, they shouldn’t have to be trying to dig into anything themselves to try and find out if there’s a problem.

[Anders]

Originally Posted by Worthmo

This summer I upgraded from a 33' bumper pull to a new 36' Rockwood 2891BH 5th wheel. One thing I have noticed is how rough the ride is with my new 5th wheel. The day I drove off the dealers lot with with my camper the heavy glass insert popped off the fireplace on my 30 minute ride home. I have the Andersen Ultimate hitch so I don't feel it is a chucking issue but the camper is bouncing and causes the truck to bounce. I had air bags installed on the truck but the bouncing continues to be an issue.

We went on a camping trip this past weekend that was 1.5 hours from our house. When we arrived the fireplace insert again had popped off, I had several drawers that opened, TV arm swung out, and items in the cabinets had fallen over. The camper has the torsion axles so I was expecting a much smoother ride. Any thoughts or ideas are appreciated.

2018 Chevy Silverado 2500 Duramax, 2021 Rockwood 2891BH, Andersen Ultimate hitch

Consider buying a Glideride Pinbox. We got one for our old trailer and the difference was day and night