starter shimming question...Help!

Installed new flexplate, new starter and have it double shimmed on the outside bolt. When you hit the starter it turns the car over fine, but as soon as it lights off and you disengage the starter it makes a screaching noise. Why? Do I need to shim somewhere else?

 

u need more shim, the starter gear is binding on the flywheel

 

Maybe more shim, but maybe you need to tighten the belts on the car.
Rarely (never??) are three shims needed unless the crank saddles have been reworked.
In the Chevrolet manuals, there is a bit on shimming the starters, specifying an Allen key be inserted into the teeth for proper clearance. I just don't recall which size key.

Cosmo

 

Recent experience and research on aftermarket starters tell me their tolerances are way off. High dollar sfi flywheels and starters may still require as many as 8 shims. You'd think they would fit better than stockers but they don't.

 

1/8"

 

Be my first guess too.

 

Are you using starter bolts ? You shouldnt have to use starter shims with the proper starter housing , unless the starter is from auto zone !!!