Help me

So I just recently purchased a 2002 tdi but had to replace the starter but once I did the starter would sometimes grind on the ring gear. (I had a mechanic friend tell me it was probably just missing a few teeth) then one day I go to turn it on and now the starter won’t even engage the ring gear and will only occasionally grind but will not start up at all. Any advice or theory would be very helpful.

If it's at a point where it won't turn over, remove the starter and look at the ring gear.

What is this 'ring gear' you speak of?
The only starter systems I'm familiar with are toothed flywheels and the bendix on the starter.

Is this a real starter, or an autozone starter? What was the symtom of the original starter demise?

It’s referred to as a ring gear because it’s an automatic or you can call it flex plate I’ve had ppl throw out several names for it and the first starters solenoid burnt out also yes it’s a autozone starter

Also we had checked out the ring gear when the problem came up but besides a couple of metal shavings from the bendix gear grinding up on the ring gear it had no missing teeth and looked it solid shape

Then your starter is crapola.

For the record, people who like their TDI's don't buy cheap autozone starters. The TDI's are hard on starters, make sure your flywheel is ok and then buy a good Bosch or comparable OEM starter. These cheap parts stores also has a habit of selling gas starters to TDI people and they burn out in no time.

thank y’all for the advice I just ordered a oem starter and hopefully that’ll solve my problems