2010 F450 Jerking/Bucking

[flyncold]

I have read several posts throughout the internet stating violent jerking and bucking on the F450. I found these posts because i am a victim of the bucking and jerking. Looking to see if anyone has an update on what is taking place. Here is my situation

2010 F450 with 55k miles on it. Pulling a 4 horse gooseneck16ft Short Wall weighing about 16k empty. i have tested the trailer with and without trailer brakes hooked up. doesn't matter so trailer brakes are not the problem. I just bought this trailer and it is much heavier than my previous trailer. Previous trailer weighed about 5500 pounds empty and never even knew it was behind me. even when it was loaded with 4 horses it didn't phase truck. This trailer has done it since I pulled off the lot. has to be associated with the weight but have not pulled this trailer with any other truck. Only happens with my truck during the braking and mostly below 15 mph.

I hope someone has found a solution other than trading the truck off.

Thanks

[Cummins12V98]

Capt Skup wrote:
I have got a hell of a load and those numbers come from the sticker that Ford was nice enough to place in the door sill of the truck. I am not an arm chair mechanical engineer, I will go with what the manufacturers recommends. Been working fine for 5 years that way. I have used those pressure for 32,500lbs GCWR on down for the boats and toys, works just fine.

The reason I ask is the MFG will post psi based on max load the truck is rated for. That may or may not be the case with your load. Up to you, might be worth weighing the axles and compare to weight charts for your tires.

[Capt_Skup]

I have got a hell of a load and those numbers come from the sticker that Ford was nice enough to place in the door sill of the truck. I am not an arm chair mechanical engineer, I will go with what the manufacturers recommends. Been working fine for 5 years that way. I have used those pressure for 32,500lbs GCWR on down for the boats and toys, works just fine.

[Cummins12V98]

Capt Skup wrote:
'08-'10 19.5 tires, rear duals proper air pressure is 75psi, 80 on the steer wheels. I had this happen once. I have a Reese Signature Series 24k fiver hitch using one plastic disc. Looked to be too much play so I added a second disc, stacking them together. Never had another issue since. Maybe you have some movement in your gooseneck latchup, allowing the hitch to move vertically during braking.

What is your load? How does that compare to the tire inflation chart and your psi you say is proper?

[Engineer9860]

Some of the other posters brought up a point that reminded me of when I first bought my flat bed gooseneck utility trailer.

My hitch was adjustable and had set screws that tightened against the hitch in the neck to take out the slop in the adjustable neck. I had to tighten the bolts really tight to take out a whip effect.

[wittmeba]

Personally I believe it is inherent to a fifth wheel/gooseneck design trailer. With a TT (bumper pull style) the trailer frame is pushing/pulling right at the level of the tow vehicle frame.

With a 5th wheel/Gooseneck the push/pull point is elevated and adds leverage to the action of the Tow vehicle - both stopping/starting and when you hit joints in the road. I dont think you can ever get rid of all of it, but there may be some ways to reduce the effects.

[Capt_Skup]

'08-'10 19.5 tires, rear duals proper air pressure is 75psi, 80 on the steer wheels. I had this happen once. I have a Reese Signature Series 24k fiver hitch using one plastic disc. Looked to be too much play so I added a second disc, stacking them together. Never had another issue since. Maybe you have some movement in your gooseneck latchup, allowing the hitch to move vertically during braking.

[Cummins12V98]

Engineer9860 wrote:
How many miles are on your shocks? Tires properly inflated?

I have about 250,000 miles combined on two different F-450s and have never experienced the issue you describe.

I have towed more than the weight you listed behind my Chevy 2500HD, so the F-450 should be more than up to the task.....

I think too many people inflate their tires to Max Psi and wonder why the ride is so bad. I have over 4,500# pin weight and run 60 psi in the rear Duals. Plenty of air for the load.

[alboy]

Trailer frame flex??

[Engineer9860]

How many miles are on your shocks? Tires properly inflated?

I have about 250,000 miles combined on two different F-450s and have never experienced the issue you describe.

I have towed more than the weight you listed behind my Chevy 2500HD, so the F-450 should be more than up to the task.....

[MichaelC]

I have an 08 450 that did the same thing at about 30,000 miles towing a 16,000# 5TH wheel. We were on a 7,000 mile trip when about half way through I was making a real slow stop for a red light, and at about 15 MPH it started bucking Very Violently. Felt like it would tear the 5th wheel hitch right out of the bed. Did the same thing again on a slow easy stop before we got home.

Took it to my dealer. He said I need to duplicate it with him along before he could diagnose the problem. They had no clue

I towed the same trailer 100,000 miles with a SRW F-350 with the same hitch with no bucking.

I found a Ford service center in a small town in Eastern WA, that suggested that maybe the hitch was not robust enough. It was a 20,000# Reese. After checking it out, there was some slop in it after 10 years and many miles, so I replaced it with a new 22,000# reese, and has not bucked again in 14,000 miles.

Hope this helps.

[Golden_HVAC]

So it happens when braking?

What about if you apply the brake manually, does it happen?

You might try strapping a video camera pointed to the hitch, and try to duplicate the problem, and see if it has something to do with the hitch, it might be cracked or wiggling or something?

Just tossing out ideas. Normally the truck should not be pushed around by a trailer of nearly eual weight.

Fred.

[Home_Skillet]

Any reason you don't think it's the trailer?

Could be something simple as not enough weight on the goose neck.