Rear end stabilty?

[94toy22re]

My 2007 Sport V8 in feels very unstable going over rough surfaces at highway speeds, its especially bad when going over expansion joints while on on/off ramps. It hard to describe the feeling but it feels like the rear end is bouncing/shifting around. But going 30-50 MPH on a grated gravel or dirt road is no problem. I originally thought it was the XREAS shocks needing to be replaced so I installed new 5100's all around but the problem still persist. Front and rear sway bars are still attached, any ideas?

 

[Code2]

My 2007 Sport V8 in feels very unstable going over rough surfaces at highway speeds, its especially bad when going over expansion joints while on on/off ramps. It hard to describe the feeling but it feels like the rear end is bouncing/shifting around. But going 30-50 MPH on a grated gravel or dirt road is no problem. I originally thought it was the XREAS shocks needing to be replaced so I installed new 5100's all around but the problem still persist. Front and rear sway bars are still attached, any ideas?

tires

 

[94toy22re]

It has 265/70/17 Cooper At/3 with less then 15,000 miles on them, i have varied the psi between 32-45 psi and nothing has made a difference!

 

[Onefastchevy]

Did you do the springs as well?

 

[Onefastchevy]

Could be worn bushings as well. Just because things are attached does not mean they are doing their job.

 

[94toy22re]

Stock springs, Sway bar Bushings?

 

[Civiceg94]

You should start checking all the bushing start prying try to move them to see if you find bushing that are worn. Sometimes it helps to take off the weight of the suspension.

 

[Code2]

It has 265/70/17 Cooper At/3 with less then 15,000 miles on them, i have varied the psi between 32-45 psi and nothing has made a difference!

Have you have them looked at for abnormal wear? Lets not forget they are all terrain tires so that may has some effect also. Check the tires along with what the others have suggested.

 

[ecally]

Check sway bar end links as well.

 

[07V8]

How old are your tires?

 

[CXS]

I'd suspect the springs, good shocks with bad springs don't help much. As others have said sway bar bushings are suspect. How many miles on your truck?

 

[JB.]

My 2007 Sport V8 in feels very unstable going over rough surfaces at highway speeds, its especially bad when going over expansion joints while on on/off ramps. It hard to describe the feeling but it feels like the rear end is bouncing/shifting around. But going 30-50 MPH on a grated gravel or dirt road is no problem. I originally thought it was the XREAS shocks needing to be replaced so I installed new 5100's all around but the problem still persist. Front and rear sway bars are still attached, any ideas?

What are you comparing it to?

If your truck has changed, you have something to investigate. If you're comparing it to an SUV with independent rear suspension, it may simply be that.

 

[94toy22re]

My 1984 22r 4x4 pickup with a solid front axle and spartan rear locker feels more stable then the 4runner so i am pretty sure their is something wrong! I purchased the truck with the cooper a/t3 tires so not quite sure how old they are but the tires still had the nipples when i purchased the 4runner but i will check the manufacturer date this evening.

 

[t-man]

My guess would be bushings too. You have upper and lower arms, sway bars and the trac bar under there. If any are worn and bad it will shimmy. My front had that issue when the bushings went out. Wandered and felt very unstable. Replaced them all and it is tight as a frogs butt!