My service truck (03 F-350 DRW 11' utility body 4x4) Has a bad wheel hop @ 35 MPH. I have stock size tires (235 or 285 can't really remember) Pirelli Scorpions. Anyone have similair thing going??? any other MPH and the thing is like riding in a car...

 

Wheel hop is usually refered to when you are stationary and hit the gas, the rear tires achieve/lose traction quickly for few seconds. Making the vehicle "hop". What your explaining sounds like bad alignment.

 

Had it aligned at three different shops... @ 35 MPH the truck is bouncing in the rear...

 

have you had the tires balanced. that would tell you if it is something in the wheel or tire that maybe you just dont notice at different speeds (maybe a knot in the tire or something)

 

Balanced twice, Checked U-joints center joint new rotors, still have no idea

 

Do you have a 2 piece drive-shaft? Try to lower the center carrier bearing with a spacer. It did help my truck....

 

I remember reading a thread either on this site or another about your same situation. balancing and aligning and new tires didnt fix... anyway it ended up being that the hub piloted wheels werent centering on the hub correctly.
the fix was to use a few lug nuts used for stud piloted wheels to center the wheels by the studs.. on remaining studs put regular lugnuts on and tighten, remove stud piloted nuts and install remaining lugnuts.. maybe worth a try since its cheap.. wouldnt think in a million years this could be a problem, but it was.
Assuming you've checked for the obvous stuff like bulges in tires, bent rims and such

 

Few questions you can look at to help.

1. Whats the new vehicle weight with the utility box?
2. Whats the condition of the rear springs?
3. When was the last time the rear studs were checked?
4. Is there any visible damage (chips or bends) on rear studs?
5. Is there any visible damage to the wheels themselves? Chips can cause hub center wheels to center improperly
6. What is the condition of the rear shocks?
7. How is the load on the rear in terms of equipment. Shifting weight around can cause odd behavior in rear suspension with aged parts.

 

I had the same type truck years ago. We had that thing loaded to the max, thinking it weight 3 1/2 tons loaded. When I first got the truck after adding the crane, welding machine and air compressor, I went ahead a bought an air ride kit due to the truck riding the overload springs. Might not be a bad idea to invest in something like air bags so assist the rear suspension in your travels, think they're running around $300-500, and it's a good investment for the company

 

Is it possible that the "hub covers", would cause the wheel to not center or be off center a little bit.

 

Not really. Hub covers go on after the wheels are mounted.

 

Not in my case Mickey Thompson classic locks. I have to put my hub covers into the back of the wheel then mount the wheel.

 

You're using lug centric then. My Eagle 101's were the same way. My hub covers went in behind my wheel, then my lugs were acorn shaped to center my wheels.

 

The truck in question is a service truck with dual rear wheels....doubt seriously that he has any kind of hub covers that fit to the rear. We ran simulators on ours and they lugged up on the front.

 

Exactly. If anything he has the stock rears which have hub covers that snap onto the lugs. So it's still hub-centric and not lug-centric like 99% of the aftermarket wheels.