Sicktime

I took my 1970 vert to the shop to get the alignment done after replacing the stock suspension with a VBP sport suspension. The passenger side trailing arm is shimmed all the way to the left and it needs more shims to go futher left. In other words, all the shims are on the right side of the trailing arm and there is no more room to add even more shims on the right side. (needs to move the front of the trailing arm left another 0.5 degree.) The mechanic says I can add shims or washers on 2 of the 4 rear trailing arm bolts at the bearings where the half shafts come through to get the trailing arm centered on the hole in the frame. This sounds fishy. Plus I would rather not have to take the trailing arm apart. (If I have to I will.)

Is this a proper solution?
How do you know if trailing arm is bent? Are there measuements for this?
What are my options ?
I can get a photo if needed.

Thanks,
Kurt

RobbSalzmann

In this situation I might seek a second opinion before you make the diagnosis. If his rack is out of calibration it may be skewing the measurements.

doctorgene

Yes Sir; Might pose this same question to VB&P They seem like a nice bunch of guys there. It might be a bent out of shape Pocket, ( where the trailing arms fit into the frame ) in the frame. Check with a frame shop who is familiar with Corvettes. A lot of these cars have been hit in there life's. Hope you find the problem is an easy fix. Have a great one. Gene

Mike Ward

It's certainly not a proper solution. Did you remove the trailing arm recently for any work?

birdsmith

The first thing I'd be looking at is the back portion of the frame to see if it has been bent to the left, especially the right side frame horn...measure the distance between the top outer corners of your rear tires and the edges of the wheel cutouts to see if there's any appreciable difference there. 'Shimming' the rear upright with washers may correct the toe angle of the suspect wheel but is definitely not factory-approved-pretty much a bubba fix to say the least. As far as the trailing arm itself being bent, those are pretty sturdy pieces so I would expect something in the frame to bend before the TA would...

Sicktime

Thanks. I know this car was rear ended on the passenger side rear. I had to replace the rear bumber support bar because it was bent and the crease was working it way into the gas tank. (not a safe situation. The previous owner only replaced the gas tank and did not try to fix this problem.) I wonder if the accident also bent the frame or the trailing arm?

I can say the shop was able to align the other three wheels. I did go check to see if by chance during the replacement of the bumber support bar the frame went out of true. But I do not think that is an issue. There is a major support bar (4"X4") just in front of the rear axle. This does not mean that there is not an issue with the frame.

Doing a search on the forum it looks like the most likely scenario is a bent trailing arm. The driver side TA is dead center of the frame hole with a near equal number of shims. If the frame was bent I would think those shims would be off also. I guess it depends on how it is bent.

Thanks for the comments
Kurt

gkull

My question about the alignment shop person is terminology. The trailing arm shims deal with rear wheel toe. Generally it is in inches not degrees.

I would fix the problem before I would shim the trailing arm bolts

birdsmith

The extra info helps, Kurt. as unattractive as dealing with the real issue might seem that's the only way that you're gonna get to the bottom of this matter, and it sounds to me like the right rear corner of the car was whacked badly enough to cause some noticeable alignment problems. BTW I went through Midland last summer...anybody that owns a Corvette needs to stop by The Petroleum Museum and see Jim Hall's cars on display there...fantastic!

Easy Mike

Trailing arm is bent which is why the shim stack is screwy. Replace the trailing arm.

Shark Racer

Quite a number of the new machines use degrees these days.