starter shims

ok yes i know this is a dumb question but how do you know if you need to shim your starter?

What vehicle are you trying to shim your starter on? Usually you will know by the vehicle makeing a very loud grinding noise when starting? You can also see by removing your starter and inspecting the flywheel for wear on the teeth. Also check your teeth on the starter gear for damage. ie nicked or broken teeth same with flywheel. Need to post what make, model, and year for this will help you get better responses. Hope this gets you started. Good luck

I'm having a similar problem.  Small block chevy that I took out of a pickup truck and put into my street rod.  I've tried a total of 5 or 6 starters, including a new one from the parts store.  Some didn't work from the very beginning. others worked for a very short time (20 to 30 starts).  Some of the starters engaged, turned the motor, and then would not stop cranking when I let go of the key.  I seemed to have fixed that.  Latest starter worked like a champ for about 40 starts, then skipped twice and now won't even engage the flywheel at all.
Do I have a bad flywheel, or am I missing something else?

I've put up to 3/8 of an inch of shims in a starter to get it to work, so don't be afraid to put more in there!

Has anyone had a starter that engages when you hit the key, but won't disengage when you release the key?

We always see questions in here and then suggestions, but seldom a confirmation of what worked.  I read in another post that the bolts have a big effect on the starter.  The knurled sections act like lock washers and bite into the block to keep the starter from twisting and moving and that was the whole problem with mine.
I bought another new starter and 2 new bolts, installed it once with no shims and it's working like a dream.

n0pe, you're not having bad chevrolet pickup flywheel, it might be that your starter doesn't exactly fit with it that's why it's necessary to p0st your vehicle's model and year.

Today I had to shim to get a new starter to even go all the way in to the flexplate. I guess it was hitting the flexplate too close.I couldn''t believe that it was the cause of my no crank issue. The click I heard I thought was the relay, but it was the starter hitting on the flexplate. Well, now I got a spare starter :)