I put on a new starter yesterday. Tried it with no shims and it made a terrible grinding noise. Put one shim on and it still made the noise, but a little less gruesome. Added a second shim and the car started, but still had a nasty noise. Do I add a third shim? The old starter had no shims at all.

Thanks

 

Are you sure the nasty sound is coming from the starter? Usually the starter retracts back into it's casing after it's done it's job. Maybe it's getting stuck on the flex plate and casing the nasty sound. What size shims have you used so far?

 

Sorry, should have been clearer. With two shims the starter only makes the noise while its working. Once the engine has started the noise goes away.

 

I'd add another shim.

 

I had the exact same issue. I tried up to 3 full shims, started trying half shims, used a feeler gauge to measure clearance - nothing worked. Eventually, I got the car on a left and had someone start it while I was underneath; the starter wasn't going back in quick enough, so the car would start and then the gear from the starter would hit on the flex plate and make a horrible noise. I exchanged the starter (not fun with the custom headers & exhaust) and didn't need any shims on the new one.

 

i've been playing with small block Chevies for almost 25 years, and i've never needed to shim a starter... i have, however, bent a few mounting bolts that caused the starter to not mesh with the ring gear properly...