X-18 Shim, Alignment or Seat?

[Bob B.]

Hi all,

When I took the seats out of my 1960, the seat frames were shimmed with what looks like front end alignment shims, roughly tuning fork shaped, and marked X-18. I'm assuming that someone put them there to lift up the seats slightly (although they are only 1/8-inch thick).

I am wondering if anyone has seen these used on their seat frames. If not, does anyone know for what use/years the X-18 shim was specified?

Thanks,

Bob

[Geoff C.]

Bubba *NM*

[Joseph T.]

Not so fast!

Bubba maybe...or maybe not!

Corvette news very early on..showed how race cars had shims/spacers added to the front two bottom seat mounting bolts to change the sitting angle.

My 57 Nassau/Daytona car..has plastic spacers added in the front two bolts and they have been there since at least 1958. Have your seat bottom springs been removed as well?

Joe Trybulec

[Anthony F.]

[Bob B.]

Re: Not so fast!

Joe,

Corvette is just the base engine car. Engine had the GM tabs still on it. Doesn't look like it was raced. The seat cushions even still had the paper tags. The AIM calls for two flat washers between the seat frame and the tracks at each of the four bolts. Mine had no washers, but had the X-18 shims. I'm thinking that some factory worker found it easier to start the bolts and then slide in shims instead of trying to get washers to stay in place without falling out.

Thanks,

Bob

[Joseph T.]

Re: shims

Bob...

Take pictures of what you found as it may help someone else in the future!

Joe

[Gary Schisler]

Are you sure you aren't

confusing C3s? They (at least 70-72s did) had a small cloth bag with eight round washer-like spacers and four rectangular spacers. This is spelled out in the 70-72 TIM & JG and I don't recall seeing this called for in the 66 TIM & JG.

Gary