Hi,

Keep in mind this is NOT a show car but just something that my wife and I can cruse around in on a nice day. My goal is to have everything working the way it should - within reason (budget). I've got some questions about rear alignment, specifically trailing arm shim adjustment for toe. I've scoured Google (much information coming from this site) and have not found the information I'm looking for... I've rebuild the half shafts, new adjustable strut rods, shock mount ect. I didn't touch anything else as it looked to be "okay". I put everything back together and wanted to adjust the camber as I put new strut rods in...got that done with a tool I made and appears to be pretty good - neg .5 degrees. I looked at the toe (as best I could) and it's obvious that the RR is "out" or positive and the LR appears to be toed in or negative. Both TA have two large shims (1/8"?) inboard and fillers on the outboard. My question is this....how much movement to you get per shim (assuming) a large shim? I'm afraid that I may have to remove all the inboard shims to get any movement and that it wont be enough to get the correct toe and thrust angle. ANY insight you guys or gals may have would be great!

I really just want to get it close before I take it to a shop. There are a few around. I did call one to see if they could give me some advise and he said bring the car and $2k to get started. and he's going to replace TAs etc... I was like, dude, I just want to get something close with what I have!

I just bought a new shim kit from willcox and will look to do as much as I can myself. Tricks to pulling the old bolt out? I'll post some pictures. Thanks again.

 

Hi n,
I'll begin with the last thing you posted…. the t-arm bolt shouldn't have to come out to remove the old shims. The shims should have a slot on the end that gets inserted into the t-arm frame pocket while the hole at the other end is for the long cotter pin that secures the shims in place. This allows the shims to be easily moved from side to side as needed for the rear alignment.
The bolt should only be removed if you want to remove the t-arm.
Regards,
Alan

 

Some pictures of the LR and RR TA's.

 

Thanks Alan! When I loosen the bolt, do I just pry the old ones out and use a pry bar to move the TA to get the toe somewhat right?

 

Yep, and move those shims to the other side of the bushing.

 

On the outboard side of the left TA, it looks like somebody used a washer as a shim. If so, you will need to partially remove the bolt if you need to remove shims. I don't think I'd try to move the TA bolt without taking the spring tension off the TA.

If you want an 1/8" (0.125") toe in you would add slightly more than 0.125" outboard because the distance between the wheel center to the trailing arm bolt is a little longer than the radius of your tire. I think the distance from the TA bolt to the wheel center is ~15", while a 26" tire has a radius of 13". If you want to add 0.125 toe in you would add 15/13 * 0.125, or 0.144" of shims to the outboard side and remove the same amount from the inboard side for each 1/8" toe in...assuming that your TA pocket is full of shims. The 15 in the above equation might not be exact; I don't remember the exact distance.

My car had more total shim thickness than you seem to have, so it appears you are limited in the amount of movement.

Make sure you put a cotter pin back in to hold the shims

 

From your pics, I would recommend replacing the bushings in the TA's....AND have someone qualified look at your bearings in the TA's....I know it's probably more involved than you wanted to get, but it's up to you...just input from someone who rebuilt my entire rear (and front) suspension this last winter....WELL worth the time, effort & $$!!
I had Gary at www.vtechcorvette.com in Illinois rebuild my TA's, as he does it every day, and I don't have the tooling or knowledge to do it CORRECTLY!! He found that the bearing flange on the right side was worn enough where the bearings would literally just fall into the flange, when they SHOULD be a light press fit!!

 

Thanks for all the great input! I would love to put new TA's in but I don't think it's quite in my budget - this year anyway. I'm in no rush, but do want to make it as "right" as I can in the mean time... I'll see what I can do with the shim kit then take it in and see how far off I am! I'll also look-up vtech. I'm also really close to Zip - I'm not sure if anyone has experience with their rebuilds? What's a fair price for rebuilds?

 

Hi Nix,

You don't say how far your toe-out and toe-in is, but I found exactly the same issue when I first tried to set the rear toe on my '76.

This was about 19 years ago, and I can't remember if I couldn't fix the toe-in on one side or the toe-out on the other, but the cause was that one drive shaft was a different length to the other.

A previous owner had changed a drive shaft and fitted the wrong length.
I would double check your shaft lengths are equal before going to town on those shims.

Good luck.

PS. I have just tried a google search to find the different lengths, and there is very little info, but trust me, I had to replace one of mine to get them the same and get my rear tracking on track