If it has shims now and you buy an OEM replacement starter, then use the shims. If it does not have shims then you will not need them. Replace the starter with an exactly duplicate, installed exactly as the original. If in doubt measure the distance from the mounting plate face to the end of the drive gear shaft and make sure that distance in the same on the replacement starter.
Between starter and block this increases clearance between teeth and flywheel or flex plate.
Remove the positive battery cable first. The starter is on the passenger side of the engine. Might be easier to get to from below. Remove the bolts holding the wiring to it than the bolts that mount the starter in place. Be careful if it has shims that you make sure you put them back in the same way. (These are little thin spacers that go between the mounting surface and the starter). Installation is reverse. Probably would take you no more than 30 minutes to do it all.
Disconnect the - battery terminal Raise and support vehicle Remove wiring harness at top of starter Remove starter mounting bolts Remove starter
Do not install the shims. Your starter should work fine.
between the starter and what it is bolted to
You should be able to buy starter shims at any auto parts outlet. If not their you could get them at the dealers parts department.
Check the backlash between the starter drive and the ring gear after installation. If it's too tight, use shims.
Disconnect battery. Then the electrical connection on the starter solenoid. Remove the starter bolts and the starter. Note the location of the spacer shims. Installation is the reverse. Don't forget the spacers shims or you will get noise when starting the vehicle.
There are several shims that could be used such as starter shims (for adjusting drive gear to ring gear), caster/camber shims (for front end alignment), body shims (for aligning body panels),
Shims bring the starter closer or further from the ring gear for proper alignment.
No, you should get new shims from wherever you got the new starter, but if not, make sure they go back into the same position they where. New shims, make sure they are the same thickness as the old ones.
The starter drive gear will be too close to the flywheel, causing a grinding noise when the starter is engaged.