69 Chassis cotter pins finish

[Greg L.]

Are these cotter pins zinc or natural or a little of each? I'm thinking that they are all natural but wanted to check and be sure before I start putting them in.

[Joe L.]

Re: 69 Chassis cotter pins finish

Are these cotter pins zinc or natural or a little of each? I'm thinking that they are all natural but wanted to check and be sure before I start putting them in.

Greg------


Virtually all, if not absolutely all, cotter pins used on any 63-82 Corvette chassis were NATURAL STEEL. This even includes the special long cotter pins used for retention of the rear toe shims for 1970-82 and the ones used for front disc brake pad retention for 1966-75 with J-56 brakes.

The above is in contrast to C4 models in which metric size fasteners were used for most chassis applications. GM used one coating or another for metric-sized cotter pins, although a few were plain.

By the way, use plain steel cotter pins at your own "risk". You'd never catch me using them. I use zinc plated or stainless cotter pins. The stainless look pretty much like plain steel AS THE PLAIN STEEL APPEARED WHEN THEY WERE FIRST INSTALLED ON THE CAR. They might not pass a "magnet test", though.

[Greg L.]

Re: 69 Chassis cotter pins finish

I was pretty sure that they were natural but one of the vendors is selling a kit that was "put together" by one of our NCRS judges as being correct BUT they are zinc plated so I started to second guess myself. Thanks for clearing that up.

So did the 69 and earlier Corvettes not use the long cotter pin for the rear toe shims? I still had the original non slotted toe shims but I assumed that someone had at one time taken out the long cotter pin but maybe it was never there...

What is the risk concern with plain steel cotter pins?

[Joe L.]

Re: 69 Chassis cotter pins finish

I was pretty sure that they were natural but one of the vendors is selling a kit that was "put together" by one of our NCRS judges as being correct BUT they are zinc plated so I started to second guess myself. Thanks for clearing that up.

So did the 69 and earlier Corvettes not use the long cotter pin for the rear toe shims? I still had the original non slotted toe shims but I assumed that someone had at one time taken out the long cotter pin but maybe it was never there...

What is the risk concern with plain steel cotter pins?

Greg-----

The 1969 AIM shows that the cotter pins were added at some point during the model year. However, my mid-September-built, original owner 69 never had them. It has the holes in the frame for the cotter pins, but no pins were originally installed.

Generally, 1969's have the "2 hole" shims which don't really require the cotter pins. My car had a mixture of slotted and 2 hole shims. I was in the service bay at Central Chevrolet when the first rear wheel alignment was done and very well recall discussing the issue with the mechanic doing the alignment. Normally, they would not allow customers to be in the service area, but I was an exception. I got my "special pass" in 1966 with my Chevelle SS 396 and I "kept it" throughout. Actually, my 69 was not in the service bays at Central very much. Only for warranty work and things I could not do, mainly wheel alignment. My 69 was only back to the Central twice for warranty work, both times fairly minor.

The "risk" with plain steel cotter pins is that they'll rust and, thus, look different than they did when they were installed.

[Tom L.]

Re: 69 Chassis cotter pins finish

Greg,

There was a post on the shim issue about two weeks ago. As I recall from that thread, the slotted shims didn't appear until very late in '70. My June '70 car had non-slotted shims that hung out of the back of the t/a opening in the frame and did not use the cotter pin.