1966 Trailing Arm Question

[Rob Fearon]

[John H.]

Re: 1966 Trailing Arm Question

Rob -

The Assembly Instruction Manuals and the Chassis Service Manual show the installation quite clearly; the pin arrangement from the C3 years is good insurance against losing the (slotted) shims.

[Donald T.]

Re: 1966 Trailing Arm Question

The installation of the correct shims is not complicated, just a real pain. You just have to remove the trailing arm pivot bolt. The bolt then goes through the shims on either side of the trailing arm. Obviously, the alignment is adjusted by changing the number and thickness of shims from outboard to inboard and vise versa. The alignment shop should be able to do it for you, although I would imagine they will charge extra for the additional labor.

[Bob R.]

Re: 1966 Trailing Arm Question

I don't know if the explainations above actually answered your question. The original C-2 shims had a hole in them. To install them you have to remove the trailing arm bolt, install the shims and then place the bolt through the shims. The newer replacement shims have a slotted end. They can be slid into place without removing the bolts. The pin is then installed to prevent the shims from falling out.
I believe several vendors still sell the correct shims. I think Blairs has them.

[Mike Cobine]

It will cost much, much more.

While you may want it correct, here is some thoughts on it.

If you are driving it, and not judging it, leave it with the slotted shims. You may need to align later and it is much cheaper to align with them.

As others have said, you must pull the bolt out to install, remove, and reset the shims during alignment with the originals that have only a hole for the bolt. This GREATLY increases the labor and one of two things will happen in your shop.

1. The Alignment guy will say to heck with that work when he can't get the bolt out and your rear will NOT be aligned. You may be charged anyway.

2. The guy will spend the day trying to get the bolt out, probably sawing or torching it out, and then charge you for all the parts he has to replace. The labor time goes up greatly, and at the hourly rate, you will find your $49.99 alignment suddenly goes to $200 or $300. Are you ready for that?

Long ago, I reassembled the '68 with the old bolts because the new ones hadn't arrived. I dropped it off at the Chevy dealer for alignment and found the bolts had come in. I took the bolts around to the shop foreman and asked that while they were aligning the rear, to install these new bolts rather than the old ones as I knew the shims had to be installed anyway (missing).

Unknown to me, they were using the newer slotted shims but they did install the new bolts. The published $16 rear aligment went to $120 back in 1977.

In my case, I sued and got the money back because they had done two things wrong - did not charge at the advertised price and had failed to notify me that the price was higher (it is on the form you sign, above a certain percentage, you have to be notified but not below that - $120 vs $16 is really up there in percentage.)

But in your case, I imagine they will inform you that it is higher.

If you really want them in, do this:

1. Plan a full day.
2. Remove the spring ends from the trailing arms.
3. Remove the bolts from the trailing arms.
4. Measure the shims out of each inner and outer on both sides and install the correct shims in the same amount.
5. Polish the bolt and coat it with anti-seize.
6. Reinstall.
7. Take it to your alignment shop for them to check.

As a side note, if your bolt is rusted in the trailing arm bushing like most, if you have slotted shims you can get it out. If you have original single hole shims, you will have to cut it out.

Loosen the bolt.
Remove the shims.
Pull bolt.
Cuss a lot when it doesn't come out.
Drown in Liquid Wrench.
Learn new words to say.
Then get smart:
- Take a large pry bar and pry the end of the TA by the bushing one way and then the other to break it free of the rust.
- Keep drowning in Liquid Wrench.
- Begin prying the TA towards the bolt end, not the head.
- Shove TA and bolt inward so head sticks out from frame.
- Insert something under head to hold it, like ViseGrips, slotted shims, etc.
- Pry on TA at bushing to move it towards the end.
- shove TA and bolt inward again and add more shims, ViseGrips, etc.
- Pry again.
- Keep doing it until the bolt is out.

[Joe L.]

Re: 1966 Trailing Arm Question

Rob-----

As others have described, the 1963 through about early 1969 did not have the holes in the frame for the long cotter pin which help to retain the trailing arm shims. From about later 1969 through 1982, the frames did have the holes.

Also, beginning in later 1969 the design of the shims changed. The 64-early 69 shims had an "oblong" hole on either end; later 1969 through 1982 had an oblong hole on the outer end and a slot on the inner end. 1963 used a different style slotted shim. My original owner 1969 was originally built with a combination of slotted and non-slotted shims and, although it has the holes in the frame for the pins, no pins were originally installed in my car.

I DEFINITELY DO NOT RECOMMEND the use of the "2 hole" shims for ANY 63+ Corvette. While they are available in reproduction, the use of these represents a foolish and silly adherence to originality. For one thing, without the installation of the cotter pins, it's virtually impossible to tell if the shims are the slotted variety. In my opinion, the shims, if properly installed (i.e a tight shim pack) and positioned down in the frame pocket, will not fall out. In fact, for the last 30+ years, or so, my car has had only the slotted shims installed and no cotter pins installed and I've never lost a shim. Nevertheless, installing the long cotter pins is a good idea, REGARDLESS of whether or not it was ever originally done for 63-69 Corvettes.

My recommendation to you is to use ONLY the slotted style shims AND install the long cotter pins.

[Michael W.]

Re: 1966 Trailing Arm Question

Agree with Joe, you don't want to mess with the two hole shims, and running slotted shims with no cotter pin can lead to loss of shims on the road as you have already have seen.

Robert C. can add another testimonial next time we all meet up.

Regards to Sue and yourself

Mike

[Rob Fearon]

Re: 1966 Trailing Arm Question

Thank you all for the VALUABLE advice ... sincerely appreciate it.

Rob

[Terry F.]

Re: 1966 Trailing Arm Question

I plan on doing this when I have the rear aligned on my car....I will have it aligned with the slotted shims because of cost. I will then bring the car home and measure the shims and reinstall the original shims. I can change them out fairly fast. Not that big a deal really, Terry

Too bad that guy drilled those holes though. I would probably bondo them in and hit them with some black paint. Later, Terry