90 blazer, starter problems, grinding at flywheel, tried, new bolts, shims, and new starter, how often do you have to use 1/2 shims?

How long has it been grinding for the reason i ask is if you have replaced the starter its not the bendex drive gear and also had to shim it witch is for minior alinement uses then there must be a problem with the flywheel make sure have it seated correctly get rid of the shims for now look at the drive gear see how badly its chewed up now you can replace just the gear if need be Its hard ot damage a flywheel to the point where its unuseable So try the alingiment again make sure of it i know there tough to get at good luck

Inspect fly wheel good could have bad ring gear. check torque convertor bolts they are tigth. with starter bolted up NO SHIMS push out pinion gear and check clearance at flywheel teeth . you can use a feeler gauge (ROUND DIAMETER) measure clearance between top of flywheel ring gear tooth & bottom tooth of pinion tooth on starter clearance should be 0.01-0.06inchs. can ge shim in different gauges. DONT USE MORE THAN 2 SHIMS. some times you have to shim them but not often most of the time if use shims have a flywheel issue.