My starter on my 307 grinds while cranking.
It had no shims to start (bought it that way) I put in a 1/32" shim straight across and it sounded worse. I took that shim out and put in 1/32" outside. It sounded better. I put in another 1/32" on the outside and it sounded better, but not perfect. I put in a 1/64" also on the outside and it sounded worse. I was close to perfect, but can still here a little grinding. What should I do?

Chevelle,
The GM spec calls for .050 gap between the teeth of the starter gear and the teeth of the flywheel. The only real way to check this and get it exact, is to take the solonoid off the starter, put the starter back on the motor, engage the gear manually and measuring the gap with a wire type spark plug gap gage. The gap is measured between the "top" of one starter gear tooth and the "valley" in the flywheel gear that it sits in. If this is hard to visualize, let me know and I can e-mail you a drawing. I have only had to do this actual check once. Usually you can get it right by adding or subtracting shims. You mentioned a different thickness shim on each side ?? All of the starter shims I have ever seen are all one piece, they go in and shim both sides at the same time. I have had to stack as many as three shims together to get a starter to be quiet so keep trying and it will probably end up ok.

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Also check the condition of your teeth on
your flywheel, or flexplate. I had a similar
situation on my chevelle, where my flexplate
was tweaked, causing a grinding noise when
starting.


dongil