Body Movement / Sway?

[DrCheeto]

Ok, I tried searching, but I don't know exactly how to word the issue i'm having.

I got a 96 XLT 5.0 AWD from a friend (it's been sitting for a year. Trans is borked, is stuck in forward gears, probably a fused forward clutch)

When I got it, I looked underneath and was shocked to see (amongst an ungodly amount of rust behind the rear axle) original shocks, ball joints and shackles (I use the term shackles lightly, they were completely rusted away.)

I replaced All 4 shocks with Monroe Reflex (I happened to have a new set I never installed on my previous 97), new lower ball joints, and replaced both rear shackles.

The truck drives MUCH MUCH better now, but I'm still dealing with a sway issue. It drives over bumps fine, but any imperfection, dip or crown in the road makes the whole body sway side to side, It's hard to explain, like being in a boat on choppy water. At highway speed, it's unbearable, it makes you sick after a while.

The sway bar end links are both intact, and the bushings don't look that bad.

If I park the truck and rock it side to side, it rocks a good 2-3 seconds after I stop doing it.

I'm at a loss here. I'm not fixing the trans if it's going to keep driving like this, and i've NEVER had a second gen ride this rough.

Any Input?

 

[gmanpaint]

Rebound is controlled by the shocks, so I don't know what else it could be. This is all I can think of.....

Both sway bars are intact? End links to the frame rails are all good in the back?

Leafs have all 4 in good shape? No cracks?

Tire sidewalls are in good shape and not soft or dry rotted?

 

[Carguy3J]

Yeah, I agree w/ Gman. It sounds like shocks. How long were those"new" shocks sitting around? How were they stored? Did you hand test them before putting them in by trying to cycle them through there full compression and rebound stroke? They could have gone bad while sitting. Most shocks come with instructions telling to cycle them a few times, before putting them in , in order to eliminate any air bubbles.

That said, given that the truck sat, and it's so rusty, I would go over EVERYTHING underneath, looking very closely. Look at all the bushings and suspension/leaf spring mounting points to see if something is moving around under load. Also, I was thinking; what about the body mounts? I suppose if they were bad enough, the entire body could shift around, causing a pendulum-like effect; kinda like when heavy stuff slides/slams around the truck or bed, and you can feel it move the whole vehicle.

 

[joecrna]

Did you replace the "fifth" shock. That would be the transverse one in the rear.

 

[my98nnj]

What tires are on the truck? What PSI are they set to?