I have (finally) fixed all of the serious bubba issues on my 68 convert, so I am just now able to start checking adjustment of components, instead of replacing them. The handling was twitchy and wandering when I bought the car. A complete rebuild of the front suspension, including new steering gear fixed the wandering. I checked the front end alignment after the rebuild and it was surprisingly right on specs. I did not check the back at that time, but suspected it was off. Today was a cold, damp day in northern VA, so I fired up the heater in the garage and checked the rear alignment. To put it mildly, it was WAY off. Camber is OK, but spec for toe adjustment is 3/32" toe in. Mine is 3/4 " toe out, mostly contributed by the driver side. This is a good set up for parking lot gymkhanas with mostly right turns. Looks like I have to hope the decades-old pivet nuts will come off without using dynamite so I can rearrange the shims. Photos show how bad the driver side is. The QuickTrick alignment tool shown is work every penny, just for avoiding the alignment "specialists" who have no clue how to work on old cars.

 

I like your setup. I used a similar rig, and, I used two wheel dollies on the rear to help with the alignment adjustments.

 

Hi r,
Have you checked to see IF BY CHANCE the shims are the slightly later type with slots rather than holes?
They do make rearranging them a bit easier since the t-arm bolt nut doesn't need to come off… just be loosened.
Good Luck!
Regards,
Alan

 

I can say that the nuts should come off fine.....But..as like Alan mentioned...the design of trailing arm shim makes a BIG difference.

It is more than likely the trailing arm shims are NOT the slotted design...and getting the trailing arm pivot bolt(s) out is where the FUN begins. You will knwo right away if your shims are slotted or not...by simply looking at them...if they hang out and have a ROUND hole in them.....they are the early design....if they are down in the 'pocket' and held in with a long cotter pin...they are the later design.

The slotted shims have an oblong/oval hole in the end. AND ...fi you do this adn choose to go back in with the slotted stainless shims...you will need to CAREFULLY drill a hole in and throguh the frame so the long cotter pin can be installed to make sure that they do not come out due to being slotted. When I do this....when the body is on...I use a 12" drill bit and SLOWLY drill the hole while slightly bending the bit in a slight curve.....and then when I get thought the one side of the frame in the CORRECT SPOT...the drill bit will go to the other side and drill out that side. I will start with a 1/8" drill bit and then go larger. And if my memory serves me correctly..I think I cut down the length of the drill bit while doing this so I do not damage the paint by the quarter panel wheel well edge. And I am using my 90 degree air drill also. It has been a while since I have had to do this....but this seems to be almost 100% accurate.

DUB

 

I am hoping the same. Can't remember and did not have time to take off the wheels today. But...it needs to be fixed regardless. The toe out makes every minor input from the steering wheel initiate a turn. Requires very steady hands. I had three RX-7 with Mazda's version of rear wheel steering and the feeling is similar, except it was controlled and predictable on the RX-7.

 

" to make sure that they do not come out due to being slotted"
Bubba would have just wrapped them with duct tape.

 

You do know that the width of the tire set on the rear is wider than those on the front? The front and rear tires need to be "parallel"...not "
in-line".

 

As someone else stated, track width of the front vs rear is different so your string may not be setup correct as a visual reference.

How does the tape measurements come out ? ( ignore the reference to the front wheels)

If the rear wheels measure as toe in without using the string then you only need to worry about the thurst angle. As long as the left wheel vs right wheel with reference to the front wheels is close, then your thurst angle should also be ok.

Make the string parallel to the rear wheel edges and compare left side vs right side at the distance at the front hubs. They should be similar and therefor a good thurst angle.

 

Using that string as you did would result in excessive toe-IN of both front wheels and rear wheels. Tire life would suffer a LOT.

Read up on car specs and how to properly do home wheel alignment. Better yet, take it to a GOOD pro in the alignment business. Call Corvette clubs in your area to find out who they take their cars to.

 

The toe in is determined by the alignment tool, not by the string. And yes, I know the front and rear track is different, although it is different than you guys are guessing. Wider-70 inches at front and 69 at back, due to offset of the rims. Stringing the car is to determine how much of the total toe in read by the alignment tool is contributed by each side. The string shown in the previous photo is on both sides of the car and is 71 inches wide at both front and back to give a reference point to measure from.
Your advice is noted, but not needed here.

 

Alan- I finally pulled the wheels off today and it was not my lucky day. I have the older, non-slotted type. A little more work, but will still get done.

 

I had a similar issue. Bubba had it toed in almost an inch. It wore my rear tires bare in no time. I used the same set up but with factory rims. One rim had some dings that affected my readings as I would jack it up and rotate the wheel to get 2 readings to make sure it wS accurate. I used the wheel dollies and bounced the rear up and down to get it to settle after doing the gross adjustments. Then when I was close I would pull out of the garage and back in to make sure it was fully settled. If you have the time I would get a set of the newer shims wit the slots. Use those to get your alignment and then you could measure the pack and swap them back to the originals. My car isnt stock so I opted to drill the holes as per Dubs instructions. Some day I may put the original style in but its not on the top of the list

When adjusting the track I measured from the frame in the wheel well behind the front tire. Make sure you use a light as there are frame rivets that if accidentally measured from will screw up a measurement. Ask me how I found that out.



Quick trik alignment tool. But bad rim for readings due to dents





Newer style shims with no cotter pin. Almost lost them.





I made multiple drawings to keep track of readings as I had to adjust the track as well. This was one of the last pages

 

That statement is an understatement. If you are staying with the NON slotted shims...great ready to spend an entire day on it. Or at least my luck has shown to always have to take it apart several times to get it right.

When you do this...I hope all goes well and quickly.

DUB

 

I also need to do this, my question is If do this with the body off how much of a change will happen when body is put back on? It sure would be easier to do with the body off.

Tim

 

Tim,
You are wasting your time trying to do this with the body off....due to you can not compress the suspension as if it had all the weight on it. SO...YES...what you do when the body is odd will change A LOT when you get the body back on.

Unfortunately...you have to wait to get it to curb weight. And NO JOKE...if you are using NON slotted shims...I HONESTLY and TRULY hope ANYONE who does this..... that it goes well and quickly. IT is a TOTAL pain in the backside...to put it nicely. After the 5th or 6th attempt...the words that come out of my mouth would make a nun blush.

I am not kidding.....this is NO FUN....so I wish all those that do this....the BEST. OH YEAH...I am SUPER PICKY....and will not settle for ALMOST THERE and let the car go out.....so if you are the type that gets tired of doing this and does just that..."Heck were close... and that is good enough...I am tired of messing with this"...then that is fine by me.....its your Corvette.

DUB

 

Dub,

Thanks.. I figured as much. it will be a few more months until I put the body back on for the final assembly.. I believe I put ss slotted ones in when I put the rebuilt T-Arms in.I'll check before I put body back on.

Thanks
Tim

 

DUB- I have the slotted shims ordered. Just waiting for them to arrive so I can fix one more bubba issue. I thought I had them all fixed. Warm weather is forecast tomorrow, so I may take the car out for a drive.

 

It may take a bit of time to drill the frame so the long cotter pin can go into it and prevent the shims from coming out....BUT eh amount of time and aggravation you saved is priceless.

DUB

 

I have had a set of those extra long drill bits for probably ten years. Can't remember why I bought them, but I need them now.