Flexplate grinding question - LS3 with LSA crank /4L80e w/LSA

[RDuke]

Quick question and wanted to make sure I'm not missing something obvious before I remove material from my starter motor mounting surface.

Screen shot of vid showing starter gear spinning after it's eaten away the ring gear over time:


LS3 block w/8 bolt LSA crank. Mounted to 4L80e Bowler trans. Been fighting starter spacing for a while now. Tried 3 different starters and haven't been able to get the correct spacing engagement between starter teeth and flex plate. Depth of starter gear is okay, but I can't get it closer to the flex plate. Gap is bigger than .035 and as a result it's chewed off the teeth on the ring gear and now I get to pull the trans to replace it.

Current flex plate that's destroyed is a TCI-399756 and Powermaster 9004-9 XC starter. Replacement flex plate is ATI-915737 that's about to go in.

Obviously I have no spacers between starter and the block. The crank is in the right place and confirmed with builder that it's not machined higher into the block. I'm thinking that it may just be a GM block issue/manufacturing Q/C issue whereby not enough material was taken off the mounting surface.

Am I missing something else that I'm not checking or seeing? I don't particularity want to keep pulling the trans if I don't have too. My current plan is to gap the gear distance to .030 on this new flex plate by either 'hoping' the TCI had Q/C issue or removing/machining the starter mount to close the gap.

[camcojb]

Any possibility the flexplate is backwards? To me it doesn't look like the bendix is pushing the gear far enough into the flexplate teeth. Might just be the pic.

[RDuke]

Originally Posted by camcojb

Any possibility the flexplate is backwards? To me it doesn't look like the bendix is pushing the gear far enough into the flexplate teeth. Might just be the pic.

Nope, confirmed it's not backwards. The issue isn't the distance the gear is coming out, it's the distance between the teeth.

[camcojb]

Originally Posted by RDuke

Nope, confirmed it's not backwards. The issue isn't the distance the gear is coming out, it's the distance between the teeth.

I got that, just seemed like the depth of engagement wasn't far enough. We used a Powermaster starter on my buddies LSA and the depth into the teeth was perfect. I used an MSD starter on my LS and depth was perfect. Since you've tried multiple flexplates I'd be looking at the starter. If the new flywheel looks the same then having the starter pad milled may be the only option. Do you have another starter to compare?

[RDuke]

Yea, tried 3 different starters, all the same issue. Still on the first flexplate.