My uncle has blessed me with a 67 Conv. 6cyl. I have had all engine, tranny, suspension parts replaced that would normally make a vehicle safe. The one thing I am not able to nail down is a oscillation in the left front that comes on at 32mph is most pronounced at 38mph and disappears at 42mph. ball joints, tie rods, and bushings were replaced as required. After a 160 mile RT to VT yesterday I went looking for the problem and noticed that the bracket on the sub-frame where the upper control arm mounts is rusting/cracking where the shock mounts. A search of firstgen and camaro&classics yielded no replacement steel for this region. Is this normally a fabricated item and not a replacement part that can be welded in place. Does anyone have any other ideas what might be causing the front end ocilation? Wheels are straight and tires were balanced on the car. :confused:

If you find/feel it in the left front, I would either swap tires on the front or install aknown set of good balanced tire/wheel combo. You could have a bad belt in the tire.

As far as the patch for the shock mounting, there is no aftermarket patches made for this area other than Alston Chassis making a complete bolt in subframe for $1400 USD. Or get a clone's front subframe and clean it, powder coat it and transfer everything over, if not replace, and bolt it in.

I'd probably take it to a Weld Shop or buddy and weld in a 1/8-3/16 inch thick plate/washer from the bottom, as in inside the spring pad on the frame, and weld on the top side. Do both sides of the car, if one side is this way, the other can't be far behind. It all depends upon the amount of rust.

wchp, when you had the wheels and tires checked, did you check these?

rims - check both side to side movement and up and down.

tires - Tires can be balanced and STILL have an up and down movement. You have to look from the side while tire is on spin balancer and make sure the tread of the tire is not going up and down.

Also check the condition of the drums and spindles. If you have drums, the drum can go out of balance.

I had a lot of vibration problems when I bought my 327 car. One bent rim, 2 out of round tires, cracked harmonic balancer and bent fan pulleys. they all contributed. Now with all that corrected, it's nice and smooth!

Luck, Kevin

I used one of the last shops in my area that still do on the car balancing. We straightened all of the rims first, mounted new tires, checked road force and rotated tires accordingly, machine balanced and then final balance on the car. I think spindle or drum balance would have been addressed with the on the car balance. Although... would a bad spindle only manifest itself with a dynamic forward load? Would a deteriorating upper control arm bushing manifest itself with a speed sensitive oscillation?
I have had three 66 Mustangs but this is my first Camaro and seems like I am starting at the beginning of the learning curve again with this vehicle.
Thanks for the feed back on the subframe, spoke with Chris at First gen as well and my local frame shop and everyone was of the same opinion... repair/fabricate.

A defective upper control arm bushing would do some balancing damage. I reccomend swapping with another known set of tires/wheels. The old garage spin balance job on the car is a lost art. People look at you funny. To check a spin balance, and the machine's calibration, balance the tire/wheel combo. Then, rotate the balance head 90 degrees. The truth is in the results. If a good balance, then 90* shift won't be unbalanced.