I have a 1970 LS5 (manual trans). A few months ago the starter began to go bad, so i took it in and had it replaced. To be clear, the only problem with the old starter was that it was having trouble turning the engine over when it was cold.

A couple of weeks later, the bendix on the first new starter went out, so the shop replaced the starter for me. About a month later, the bendix on the second starter went out. The first two starters were just off the shelf from autoparts store (a reputable one), so I had them replace it with a heavy duty and considerably more expensive starter. It worked fine for about another 3 weeks, and the bendix went out again.

From what I understand, it could be any one of a few different things. The shop could be installing the starters incorrectly (improperly shimmed, etc.). I have a bad flywheel (worn teeth?). Or, I am having bad luck with starters.

Could the first two starters have damaged the flywheel to the point where the new, better starter is not going to work for me? Any advice would be appreciated.

 

I'm thinking you may possibly have a grounding issue. Maybe check the block to frame ground cable, and see if that is the problem

 

Thanks for the advice. I will take a look at that. One thing I did not mention is that when the bendix "went out" on each of the starters, the gears of the starter bendix were completely torn off. Could a grounding issue cause this?

 

Uhh....no....I'd take a very close look at the ring gear on the flywheel, its most likely whats causing the problems. I had a similar problem with my starter on my stockcar....shimed the thing every way to sunday, but nothing helped. When I got under the car and looked very closely at the ring gear all the way around it was clear thats what was causing my starting issues.....its a fair bit of work to fix, but nothing too hard

 

Well, your first problem is that your mechanic probably bought the cheapest starter he could get...which would net him the most profit. If it is a foreign-made 'knock off', you can't be sure what kind of metal the thing is made of. Secondly, you need to check if the starter mounting bolts are stock GM pieces that have knurled shanks. That knurling is used to establish the proper fit and alignment of the starter to the flywheel. If 'regular' bolts are used, all bets are off.

This problem is on the back of the mechanic...not you. You took it to him with a clear problem and wanted it fixed. He's on the hook to fix it or return it to the way it was and return your money. His best 'out' is to go purchase a quality Bendix unit and get the starter/flywheel alignment done right. It could also be that the mounting holes in the [new] starter body aren't drilled at the correct locations which is throwning everything off.

Get this 'mechanic' to fix it right or "cry Uncle"...then find a better mechanic.

 

Thanks to each of you for being a great resource. I don't think the mechanic is trying to take advantage of me. In fact, they have lost money on the deal trying to make it right, which hopefully he will accomplish this go around. I am going to run both of your suggestions to ground with them today and will let you know what I find out. Thanks again.

 

I thought I would give it some time to see if the fix worked. It was teh ring gear. They kept it for me at the shop so I could see that it had been worn down in a few places. It sounds like every time the starter bendix engaged with the ring gear in the spots where it was worn down, it was damaging the bendix to the point where the whole thing would finally give. Thanks again for the advice.