Do 66 impala starters need to be shimmed?
Answer 24 to 36 months seems a bit short for the life of a starter but if you have been buying rebuilt starters, and especially if you have headers or anything non-stock about your exhaust system or heads, that may be the reason they are dying young, especially if it is the solenoids that are going out. I had similar problems on my big block Chevy when I put headers on it, because the exhaust heat was cooking the solenoids. I switched to heavy duty solenoids, and also added heat shielding on the downpipe – and that got me a life of about 50K miles per starter. As for the shims, if the starter sounds OK, it is OK. If you hear a nasty scraping sound, it means the pinion is not engaging the ring gear properly – you’ll have to add shims and experiment to find out what you need to make it sound right.
