I'm going through a starter a year on my 1999 4.3 gl. Trying to problem solve and can't find if this starter needs to be shimmed. If anyone knows would really help.
Being a 1999 it should use the offset bolt pattern starter and would need no shims. Look at the block and see if something has been damaged to the matting surface.
If all is good, then you probably need to replace the ring gear on the flywheel
I have to replace the starter and bolts every year. It starts great for a few months then starts making a terrible grinding noise. It sounds like it's destroying the fly wheel. But there are no teeth missing or rounded teeth, really no signs of abnormal wear. I replace the starter and it's fixed for a while. There's no water in the hull. Timing is good and compression is good.
most starter bolt failures are from one of 4 things:
improper bolts
improperly torqued bolts
lack of forward bracket on larger direct-drive starters
hydro-locking
