Duramax starter motor replacement

[silver89]

Two years ago I had flexplate and starter motor replaced on my 01 Duramax due to significant grinding on start up. Everything was fine (except for the bill) until about 4 months ago. Turned the key and starter made a grinding noise and truck did not start. Discovered the starter was loose. Tightened the bolts up in a mud puddle as best as I could and had no problems, before leaving on vacation I crawled under the truck to check motor again and discovered it was loose and also one of the ears on the starting mount was broken. I got new starter from Napa in a hurry since we were leaving soon. I replaced the starter motor myself which in my opinion is a significant pain in the ass to replace. When I went to start engine I heard the dreaded grinding noise that I spent a $1000 dollars to have fixed. The truck does start but grinds directly after motor is started.

My question is what is causing this and what should be my next plan of action?
At this point point I plan on removal of the Napa starter and replacing it with an Delco starter.

Did I get something wrong during installation. How can I keep the bolts from loosening again. Could the flywheel need replacement again already?

Thanks for any help.

[rapidoxidationman]

one of the ears on the starting mount was broken
is that on the starter or on the mounting flange?

[Kennedy]

The starters on these trucks tend to be very robust and give very few issues for many hundreds of thousands of miles. So good that I wouldn't be afraid to put a good used OE on. For years I have resisted buying any reman starter or alternator whenever possible. Instead, I have a semi-local auto electric ship rebuild mine.

Once you have the starter in and working properly I would pull the bolts one at a time and put a drop of red loctite on the threads. Not a lot, just a bit.

[silver89]

Thanks for your responses . An ear broke on the mounting flange. Napa starter is brand new but I think it does not disengage fast enough.