[PTNOUT]

I have 2011 crew 6 inch lift running 35's. When driving down the road and hitting bumps at highway speeds this trucks rear end will jump to the right. It will jump to the point of having to catch it with steering wheel to keep from going into other lane. Have changed shocks and everything is tight. It always goes to the right. Any ideas?

 

[skiingengineer]

This is an absolute shot from the hip, but are you sure the rear shocks are the right length? If the rear shocks are too short at the top of the bounce they would "top out" and the rear end might pull a stunt like that... any difference with loads in the back? I would assume it only does this empty?

Jumping right just might be from the right rear having the least weight on it since the driver and gas tank are on the left side.

Mine use to be more jumpy (usually to the right) on the freeway but after I lowered it with stiffer shocks (KYB MonoMax) and it calmed right down.

 

[ShredSled]

Yeah, I'd second the proper shock length question. Double check that. Your spring rate didn't change.
What shocks did you put on there? May not have enough rebound damping.
It is also possible you purchased some cheap twin-tube shocks and mounted them upside down and they are cavitating and losing damping, turning your rear end into a pogo stick.

If the bouncing is only under acceleration it may have to to do with lifting using a large block under the leaf spring and experiencing leaf wrap and wheel hop.

 

[Tim W]

did the lift come with rear springs? perhaps they're too stiff and need to break in :shrug:

 

[ShredSled]

did the lift come with rear springs? perhaps they're too stiff and need to break in :shrug:

yeah that's true, in which case the spring rate would have changed and may be overcoming the damping with no load in the back. Or shackle/hanger bolts overtightened and restricting movement of the leaf.
I was just assuming blocks were used.

 

[PTNOUT]

No it is stock springs, and have not noticed wether it makes a difference loaded or not. Guy that put on my lift ordered shocks not really sure what they are. He does it for a living and is my father-in-law. I will check shock travel and see if they are going out all the way or not.

 

[beckmand78]

Also check tire pressure.

 

[PTNOUT]

update... Changed shocks and put on Rancho 9000 solved problem. Shock were only a year old but left side shock was shot. explains why when hitting bump right side was staying planted and pulling it to the left.

 

[beckmand78]

update... Changed shocks and put on Rancho 9000 solved problem. Shock were only a year old but left side shock was shot. explains why when hitting bump right side was staying planted and pulling it to the left.

schkagbvlzmklzdxfcn;>

 

[PTNOUT]

schkagbvlzmklzdxfcn;>

???? ummmmm well maybe. LOL

 

[beckmand78]

???? ummmmm well maybe. LOL

I gave up on what I was thinking lol