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Posted by: dwillouby May 11 2022, 08:26 AM

Hello,

While working on upgrading my brakes I found that the right trailing arm has about 1/8 - 1/4 side to side movement. The shafts and bushing came from PMS both nuts are tight.

Haven't dissembled but think the bushing face may be at fault?

Thanks
David

Posted by: brant May 11 2022, 09:47 AM

usually it means the trailing arm hole or "ear" has been ovaled or wallowed out.

that 1/8 inch means your toe is changing every time you enter a corner.
can make the rear end dangerous and cause a spin also

the repair involves removing the arm. fixing the mounting hole, and reinstalling everything with a fresh 4 wheel alignment

Posted by: SirAndy May 11 2022, 11:22 AM

Also check the bushings for the shaft that goes inside the trailing arm ...

Posted by: mskala May 11 2022, 11:36 AM

It's possible to have axial movement if the length of shaft plus plastic bushings
is not exactly right. With the right side jacked up, I could push the trailing arm in/out
a bit. Not pivoting on one mounting point. Although it was not 1/8". I made up a
shim for it.

Posted by: dwillouby May 11 2022, 11:48 AM

Thanks for the replies.

There is no movement at the shaft mounting nuts. Just the horizontal side to side movement.
Will check for ovaling when I take the arm off. Just feel it may be a bad bushing?

David

Posted by: 914_teener May 11 2022, 01:12 PM

So you didn't post if you have replaced the busings or not.

If so...meaning you replaced them.

1. Did you replace with new axle shafts to the arm or reburbish the old ones?

2. Did you check the mounting hole for ovaling like Brant suggested?

3. When you install the bushing the serrated axle shaft MUST sit proud of the bushing otherwise it will never tighten and will come loose....a very bad thing.

4. Did you use the stock nut and did you get new ones or used?

5. Did you realign the rear end when you replaced them are are the chassis mount nuts tight?

I feel like you haven't told us enough to determine what is happening. Pictures are always nice.

Posted by: dwillouby May 11 2022, 02:16 PM

1. Did you replace with new axle shafts to the arm or reburbish the old ones?

New shafts and Delrin? bushings from PMS.

2. Did you check the mounting hole for ovaling like Brant suggested?

Haven't dissembled yet. Holes looked good when I installed the new shafts ~2,000 miles ago.

3. When you install the bushing the serrated axle shaft MUST sit proud of the bushing otherwise it will never tighten and will come loose....a very bad thing.

The shaft mounting nuts are tight on both ends. Arm can move left to right on the shaft. No movement at the mounting nuts. So assume shaft is proud of the bushings?

4. Did you use the stock nut and did you get new ones or used?

New nuts.

5. Did you realign the rear end when you replaced them are are the chassis mount nuts tight?

Yes.

I feel like you haven't told us enough to determine what is happening. Pictures are always nice.

Yes, really nothing to see at this point until I remove the arm. Have a car show this weekend less than a mile away. Will tear back into it after that.

Thanks
David

Posted by: mskala May 11 2022, 04:23 PM

With no load on the arm and with plastic bushings, it should be pretty obvious if the
arm is moving on the axle shaft or if it is pivoting around an oval hole.
Shaft can be tight to the ears and arm could still move if there is room.
Disassembly seems to be a waste of time. Block the arm from moving side-to-side,
then feel if it still moves (pivots). If not, great. If it does, then you have an ovalled
hole.