Oops...dropped a shim!

[Dauntless]

I had completed the installation of a Phantom LSD and a 8% taller 5th gear, and was moving my transmission into place to mount it to the engine when I noticed a bearing race shim lying under the table. Oops!

I have no idea which race it came from, as I removed each race and shim stack as I opened the gearbox and set them carefully aside (or so I thought!). The shim is very thin, perhaps 15-thou, so I am wondering if it should be safe to use the trans as it is, or if I am thoroughly screwed? I don't drag race thiscar, just spirited twisties driving and possible track days in future.

Anybody done this or run a 'box without all its shims?

 

[2-0turbo]

Don't 1/2 ass it. Take the thing back apart and put the shim in. No, it won't work right without it. It will function, but you are going to have accelerated gear wear, possible engagement issues and bearing wear. Do it right or don't do it at all. Last time I put my tranny together I had to take it back apart 3 times for different reasons. With it on the bench, it doesn't take that much time.