Driving & Towing 5th wheel

[Not Very Happy]

I have a 2011 F350 SWLB 4x4 and tow a 40ft 5th wheel that weighs 14500lbs. The truck has more then enough power and gets great fuel mileage empty and towing. My problem is the truck seems to bounce while empty going down the road. The dealer has had my truck for 5 weeks total to fix the problem. A field service engineer from Ford told them to do a road force balance. They did and it still accures.
When I hook up to my 5er 1st & 2nd gear rattle your teeth out. I was told that there is so much torque that it is causing the driveshaft to wrap.
With 1000's sold someone else must have this problem.
Hitch weight is 2100lbs

 

[DaveBen]

I will address a complaint of yours. My truck bounces going down the road empty. I have stiff springs from the factory in my truck. This is the fourth truck that I have owned that bounces going down the road. It is the stiff springs that Ford puts in so you can tow a heavy load. The rest is up to you or anyone who wishes to respond.

Dave...

 

[Dogman]

My 04 F350 would kill you with the bounce while empty. But backing the air in the rear tires to 55 psi when not towing would help some. I also put a better tire on it too. If you have the tow package then theres not much more you can do. Also It's a new truck everything is going to be stiff for a bit. How many miles do you have now on it?

 

[Stroked68]

Agreed with checking your tires. I put about 65psi in my tires when towing my heavy loads. Then when not towing, 50psi. Makes a big diff in ride quality. Our heavy trucks arnt made to ride like a Lincoln haha.

 

[Not Very Happy]

I've had a '99&'04 SD not my first rodeo. I expect the truck to ride like a truck not a caddy( I have a 05 sts also). The 04 had factory springs rode great put leveling springs on still rode fine. Ford is saying that all the new SD bounce going down the road. I find that hard to believe.

 

[Stroked68]

Well with not very many newer superduty's out there, I personally havent read anything about having a bounce prob. Well since yer not a newb when it comes to the good ole superdutys, i'd say this is a new one on me and you.

 

[powerboatr]

I will address a complaint of yours. My truck bounces going down the road empty. I have stiff springs from the factory in my truck. This is the fourth truck that I have owned that bounces going down the road. It is the stiff springs that Ford puts in so you can tow a heavy load. The rest is up to you or anyone who wishes to respond.

Dave...

yup
my 350 towboss killed you empty so i ran 30 lbs of air in each rear tire when i was emtpy. helped some
Ford also had a TSB for bouncing trucks at 45mph they add a big dampener on the rear frame that took some of resonance vibes down a notch

only other cure is to rip out the springs and go full air ride.

 

[Seismic Truck]

I think I have this as well (havent had my truck long, and only pulled my fifth-wheel twice). I dont have the bounce while empty though. The vibration seems to be in phase with the engine and only happens in first 2 gears. My truck is a SRW-LWB and I constantly run 70 PSI in the back and 65 in the front (20 inch wheels). I have a friend that has a 350 DRW-LWB that I'm going to email (has a friend at FORD).


About the drivehshaft wrapping, I can't imagane that is the culprit.

 

[iracemine]

I too get a bad bounce when I leave my tow pressures up when empty (65ft/70r). So I back em down to 55 when race season is over.

I would imagine you would have more axle wrap or trans shudder when pulling your 5er. My money is on a bad tire.

 

[Not Very Happy]

Ford engineer already road force balanced the tires once they are going to do it again, and adjust the body mounts.