I have a 2013 F250 diesel, two wheel drive, single wheel, with a 1000Lb added spring. I pull a Grand Design Solitude which is 38 Ft 11 in. When on the interstate and passing over bridges or uneven roads, I seem to get porpoising on the trailer. Would a set of air bags eliminate some of this? would appreciate any advise. Is it worth the $700 installed cost? We have a trip planned from central florida to Yellowstone and other parts of the western USA scheduled for August, and would consider installing them before then if they work.

I installed a set of firestone ride-rite air bags on my 2013 Ram 2500 and they do buffer some of the porpoising. I also have the Reese Airbourne Pinbox on my 35' 5th wheel and that helps as well.I installed the airbags myself in about three hours so the cost was only $300.00. Very easy to do!The air bags have done an awesome job of keeping the weight off the springs and supporting the load....but I've been thinking about the added benefit of adding an extra spring like you did.Is that a big project and expensive?Thanks,Tony

Waste of money. What you really need is more truck. There is nothing you can add that will cure overloading. If you dont believe me, load up and go to a set of scales for some accurate weight numbers. Compare those numbers to your trucks factory GVWR, GCWR, RAWR and you will have the answer.The only model that I see that comes close is either 37 or 41 feet long. The 37 footer has aa GVWR of just under 14,000 pounds, meaning you likely have a pin weight close to 3000 pounds.

Sorry, you need more truck for that load, not more springs. Have you ever run across a CAT Scales.

Yes I have. I'm over a little on my truck's GVWR but under on all other weights.My truck handles the 5er very well and the couple of additions I've made have worked out well.I don't know what the OP's weights are but airbags will definitely make a difference for him.

Some RVs just ride bad no matter what's pulling them! I had a small hybrid that jerked my Chev dually around.Between the air bags, the 5th AB hitch and the air adjust Rancho shocks, mine rides really good. Each of those gadgets uses air psi to adjust and I can do the bags and shocks from in the cab and each one REALLY makes a difference. The hitch can be adjusted but I keep it set to the indicator line on the hitch. The mfgr. says it might help to change it a little but I haven't tried it yet. I drilled a cross hole thru the hitch moving parts so I can stick a big pin in it and lock it in a level position so I can use my tripod. I took off one day and forgot to pull the pin out and it rode terrible. I knew in less than a block something was way wrong so I know the hitch helps a lot too. I don't think any one thing is a cure-all unless you get really lucky! Craig

air bags on truck to prevent porpoising | Good Sam Community

75 Replies

rgstarnes
Explorer
Jun 12, 2015
RCMAN46 wrote:
To the Op.

When I take the weights you supplied I get a trailer weight of 14140 Lbs.

With a pin weight of 3020 that gives a pin percentage of about 21%.

With long trailers and depending on how much overhang you have on the rear 21% is probably on the low side.

If you were to redistribute some weight if possible and get the pin percentage close to 25% you may see a dramatic change in the amount of porpoising.

Will try that when we load the trailer to go to Yellowstone in August. I would guess with the airbags and load distribution it should help.
RCMAN46
Explorer
Jun 11, 2015
To the Op.

When I take the weights you supplied I get a trailer weight of 14140 Lbs.

With a pin weight of 3020 that gives a pin percentage of about 21%.

With long trailers and depending on how much overhang you have on the rear 21% is probably on the low side.

If you were to redistribute some weight if possible and get the pin percentage close to 25% you may see a dramatic change in the amount of porpoising.
rskeans
Explorer
Jun 11, 2015
FWIW, I have zero porpoising/chucking etc towing my 39' 19000 lb 5ver with the RAM Dually. However, I do have Bilstien 5100 shocks installed. When I had my heavy dual slide truck camper mounted on my F350 dually, I also had air bags. Whenever the road was rough or bumpy we would crank up the air pressure to 80 lbs or so significantly improving the ride. But that would also make it top heavy so the pressure had to be reduced when in the mountains. Airbags do have their place.
krazymatt
Explorer
Jun 11, 2015
I can't tell you nor is it my business if you're overloaded or not but I recently installed a set of Airlift 5000 airbags on my 2014 Ram 2500 with on board air to help alleviate the porpoising/chucking/ roughness on the rear whatever you want to call it and I took it on a 20 mile test ride. I can tell you that the improvement was about 80%. You can still feel it but at least it is much more tolerable. It seems like the longer 5ers over 32' seem to have the problem whether you're overloaded or not.
rgstarnes
Explorer
Jun 09, 2015
07PSDCREW wrote:
RCMAN46 wrote:
If the OP will give us the CAT scale numbers I am betting we may find his pin weight percentage is way low.

Number one cause of porpoising is low pin weight percentage.

After we get actual CAT scale numbers then we can intelligently discuss if he has enough truck. Right now we are only guessing.

I didn't read all 7 pages, but I agree here. I discovered that by adding water to my front mounted fresh tank made my truck ride soo much better than when we ride with the tank empty. We were going to a park with no hookups and I filled the freshwater before leaving. What a difference!

Here are the CAT weights with trailer:
steer axle---4480
drive axle--6500
trailer axle--11020
Gross weight--22100

without the trailer:
steer axle--4480
drive axle--3480
gross weight--7960
Trailer gross weight--14040
Pin weight--3020

truck rating on sticker
steer axle--4800
drive axle--6800
gross weigh--11000
tire rating-- 3620 each
gross pulling weight of 5th wheel--16,300
rgstarnes
Explorer
Jun 09, 2015
eightball1974 wrote:
Oldme wrote:
TXiceman wrote:
Oldme wrote:
TXiceman wrote:
Quiet frankly, an F250 is not enough truck for your trailer. The added 1000# springs do not increase the trucks weight rating.

Some times the truck bouncing is cause by too light of a pin weight.

Ken

I think ypu missed the part where the truck was RE-CERTIFIED
for the new capacity.

Tampa Spring, where his was done, is licensed to RE-CERTIFY
for the change in load capacity.

The only true certification is by the original manufacturer or a factory certified upfitter.

Ken

Correct.
That is WHY Tampa Spring can re-certify.

Hello I had a question for you since your from Tampa. I just got a 35ft Impact toy Hauler, I noticed my 2015 F250 sags down just about to the yellow bump stops on the frame. I was thinking about adding the leaf spring but then figured that would just give me a rougher ride when not towing so thinking about air bags and noticed you were getting them soon. Wanted to know if you don't mind me asking where you were going to for them. Thanks.

I did not get a rougher ride from the added spring. It was firmer, but not rough.
rgstarnes
Explorer
Jun 08, 2015
I also just purchased new tires to replace the original ones, and I got tires rated for carrying about 3620 lbs each. The current weigh on the rear axle loaded was 6600. The original tires were rated at 3416 lbs each. The truck is rated for 6800 lbs.
rgstarnes
Explorer
Jun 08, 2015
Eight ball, I got the spring from Tampa spring and the airbags from Mullins 4x4 in Ocala. My truck didn't have a level issue, just that I wanted to take some bounce out over bridges.

I think I accomplished that goal and am confident that the truck is capable of handling the 5 th wheel. All my weights were in the safe zone for the specs on the truck, so I will test the airbags soon and let you know.
gtsum
Explorer
Jun 05, 2015
Haha. Touché!
Cummins12V98
Explorer III
Jun 05, 2015
gtsum wrote:
Cummins12V98 wrote:
With only 3,200# pin you should not have need to do anything to "level" your truck. Blisten's would have helped and not running over 55 psi on your rear tires. Airbag kingpin also helps!

I have about 4k in the truck with me and family and hitch and misc and the pin weight. I squatted about 4.5 inches when hooked up without timbrens. I am just under the 7k axle and gvwr of 12400. She is loaded down pretty good. I have a srw and with almost 7k on the drive axle I need my rear tires at max pressure (80). Tired r rated at 3640 at 80psi each, so not sure how I could run lower psi?

I have a 6'4" bed and went with same hitch you have so I needed a sidewinder pin box. The air ride sidewinder is only rated to 16k...my rig is 16500 gvwr so I went with the 19k non air ride sidewinder

I might well go to a ram dually with air ride and get a ts3 hitch and call it good....even though I just ordered my truck last year....will see how it does on a 3k mile trip this summer:)

Sorry, my mistake for some reason I thought you had a Dually.

Now I can say a Dually would probably been better for your load.:B