Front End Shifting on Right Turns

[1999montana]

Has anyone ever encountered this issue with the Pontiac vans?

Ours is a 1999. I had the trans rebuilt last year. The trans shop dropped the sub frame to get the trans out.

Had a front end alignment done last year too as I had the trans shop install a new rack (old one was leaking) while the sub frame was lowered.

Had to take the van in for an alignment and afterwards the steering wheel would not center. Plus, on right turns you could hear something shift a small amount and when the van straightened out, the wheel was in a different position as if the sub frame was shifting on the four bolts that attach it to the chassis. But the bolts and the isolators are tight.

The steering rack is bolted in tight, I've checked it. The front and rear bushings on the control arms are good as are the shock mounts. But the steering wheel will re-center to a new 'center' each time something shifts left or right.

I thought it was perhaps the front brakes making the noise and causing drag on the rotors causing a pull left or right, but after doing the brakes (new rotors and pads; old rotors were warped) it changed the sound a bit, but the sound and feeling that something is shifting is still there on right turns. Outer tie rods are new and tight, lower control arms are new and the shocks were replaced with quick struts around the same time as the control arms.

Is there any way to check for this sound and possible shifting, and what if any remedy is available to correct it?

[gmtech1]

If all the mounting bolts are tight, its possible there is a problem with the rack itself. Usually its the rack mount bolts being loose, but you say they are tight.

[1999montana]

Originally Posted by gmtech1

If all the mounting bolts are tight, its possible there is a problem with the rack itself. Usually its the rack mount bolts being loose, but you say they are tight.

Yes, see that's my issue. Everything looks and feels tight. The mounts on the body that accept the sub frame are clear of rust and corrosion too.

Could there still be an issue with the rack (reman Fenco replacement)?

How to check it is my issue, unless the shop can check the rack on a hoist where the weigh is still on the wheels.

[gmtech1]

Originally Posted by 1999montana

Yes, see that's my issue. Everything looks and feels tight. The mounts on the body that accept the sub frame are clear of rust and corrosion too.

Could there still be an issue with the rack (reman Fenco replacement)?

How to check it is my issue, unless the shop can check the rack on a hoist where the weigh is still on the wheels.

As you stated, would be best to have the vehicle on a drive on rack. Then have someone in the van turning the steering wheel lock to lock while someone else is under it watching the steering rack, linkage, mounts, ect...

[rkvons]

Are your strut holes at the socket slotted? The bolts down there might be loose and your camber might be shifting. They probably loosened those bolts to drop the subframe, leaving the struts hanging by the upper mounts.

[1999montana]

Originally Posted by rkvons

Are your strut holes at the socket slotted? The bolts down there might be loose and your camber might be shifting. They probably loosened those bolts to drop the subframe, leaving the struts hanging by the upper mounts.

Thanks for the reply. As I understand the process, they do lower the sub frame more on the left in order to get the trans to slide out on the driver's side. I don't think the sub frame was lowered all the way or left hanging. While they worked on the trans the van was temporarily put back together and rolled out of the shop using a cross member placed across the engine bay (fender to fender) supporting the engine and sub frame.

The van was aligned after the trans repair. I think I should have the alignment folks go over the van a little closer to see if anything might be moving while the van is on 4 wheels.

[1999montana]

Well, we finally got to the bottom of this problem, literally!

Turns out the THIRD set of Dorman aftermarket controls arms with less than 30,000 KMs on them are shot. Bushings are separating and ball joints (non-serviceable) are sloppy.

All the Dorman control arms have a lifetime warranty that includes labor to replace them. Dorman decided to have genuine GM OE arms installed at their expense. This would be the fourth set in less than 80,000 KMs. Shop ordered them in and installed them yesterday; - Dorman paid for everything.

What a difference without the shifting and clunking.

Will see how they perform.

[Tech II]

The guys doing the last alignment did not do their job....they are suppose to check out ALL FRONT END COMPONENTS, before doing the alignment....obviously, they didn't...

[1999montana]

Originally Posted by Tech II

The guys doing the last alignment did not do their job....they are suppose to check out ALL FRONT END COMPONENTS, before doing the alignment....obviously, they didn't...

The real crazy part is you place your trust in people who should do the right thing, but often don't. That's why I check everything over after the van has been in the shop to make sure that nothing has been missed. Found too many bolts not tightened and things left dangling than I care to mention. Hard to get good help; - even in a dealership.

Case in point, they didn't use a torque stick on the wheel nuts when my new tires were installed, so I have to break them all loose and re-torque them.