Hi C3 people,

I've got some play in my trailing arms and I'm not to sure what's going on. I've checked the end play and there is hardly any that I can tell without a dial gauge.
When I check by grabbing the wheels moving them up and down they move about a 1/8" to 3/16".
When I check on the inside with my son moving the wheels the movement seems to coming from the differential spindles.
My question is how much should these spindles move in and out of the differential and is this also caused by the bushings in the trailing arms.

Thanks

Canadianvette

I guess I'm not following. What moved 1/8 inch? At the diff, or at the wheels?

It's moving at the differential and the bushing at the trailing arm looks like it's rotating on the bolt, but it's hard to tell for the bushing.


Thanks

Canadianvette

The drive shafts have to slip a bit to allow for raising and lowering of the suspension while driving. So some in out movement at the slip point is okay. Up and down would be a problem.
I am concerned about the bushing for the rear. They should not allow the wheels to tilt. A slight flexing is okay, but not the kind of movement you are talking about. Check all the rear suspension bushings closely. Sounds like they may be worn out. This will affect ride, handling, tire wear, and eventually safety.

I'm a bit confused here too! Are we talking about the bushing at the trailing arm and frame? If so, you should only have up and down movement, if you have lateral there, you may have lost a shim or two. Or worst case the bushing there is worn.
At the wheel, a quick check I use is to grab the wheel top end bottom, do a "push pull" top to bottom. It's ok to feel just a bit of movement, too much and it's either set up wrong, or worn.

Spindle end play at the differential should be no greater then .050". More end play would indicate the spindles are worn at the ends from rubbing against the cross shaft. Worn strut bushings will also cause play in and out (top and bottom movement)of the wheel. I know of many that have more play then .050 and they still manage to get down the road, but it should be taken care of before it causes more problems with something else. The previous owner of my car neglected the end play so much that the spindles ground right through the housing where the seals are installed. Had to get a different housing.

Too much play when you shake your rear wheels sounds like your wheel bearings are shot.

Great info, thanks,

Here's some more info.
2 years ago I changed the strut rods and all the universal joints, shock mounts, leaf spring and I checked the spindles against a new one that I had in stock and the lengths of them were okay.

After reading all of your suggestions I'm leaning towards the bushings and the shims as I looked at it on a lift last night and got a better look at it and the shims at the trailing arms at the frame look pretty bad.

I'm going to pull it apart and change the bushings and install new shims to see if will fix the problem.

Thanks alot for all the info,

Canadianvette

Very nice car! Did someone build the hood or buy it after market? Do's anybody know were I can get one of these hoods to fit a 75?
george

I guess I should clarify my answer a bit. I was a bit tired when I wrote it and it's not clear.

Yes there has to be some movement up and down due to suspension travel, but the diff and drive shafts is what holds the top of the wheels in place. If the top of the tire moves in and out, look at the end play in the diff yokes. A sloppy u-joint can cause this also, but you would hear a lot of clunking so that's not likely your problem.

Check the bushing on the arms, and the endplay in the diff yoke.