jhoski

This is one of the subtle differences of the L series motors. There are 2 sizes of drive and spindle gears. They will always go together, however will fail if mis-matched. This happens exactly the way you describe. The drive gear explodes. You probably had a large spindle gear being used with a drive grear for a small spindle gear. You should try and keep the spindle and drive gears as matched pairs to be safe. The factory used matched pairs when they originally built them. I've had this happen too and it took us lining up several spindles to finally see the difference. I ran across your post because I'm trying to sort out which years used which sizes because I just picked up an L28 stroker that did not come with a drive spindle. You cannot just drop any Z spindle in and I havn't confirmed yet which years are which.