I just completed getting my engine back together however, when I try starting it the starter pinion gear stays locked into the flex-plate. I have tried all the following:

Shimmed both sides (still locks in place I shimmed it so much that the teeth start making that teeth missing sound, but still locks in flex-plate.

Shimmed just the inside and outside separately, same results locks into place.

Got a new starter thinking the old one didn't have it anymore, does the same with the new one.

The flex-plate is installed correctly (you only need to do that once to learn a lesson).

It just seems that the angle of the starter no longer matches the flex-plate angle. The pinion pulls back once I start to loosen the bolts and tap it. I have checked with all my local experts none have seen it before so the give the same advise as the things I've already tried. One did say he had it with a bent starter bolt, but all of mine seem true.

Anyone have a thought on this one?

Thanks,

 

Are you using the support bracket that attaches to the end of the armature housing and the engine block??? IF not...install it...it holds the armature housing SOLID and not allow any movement.

I have encountered this EXACT SAME thing. To where I had to loosen up the start bolts to get the bendix to disengage.

You are aware that they do make starter shims for BOTH designs of GM starters. The angled bolt pattern takes a 'zig-zag' looking shim or the straight across bolt pattern takes a shim that is just that...straight across.

I do not do anything but install the shim thickness that I need and have fixed any that ahve an issue and I do not try to put more shims for one bolt or the other. In 30+ years...never had to do that.

I ALWAYS start with the thinnest shim that comes in the pack of shims and go from there.

I also make sure I am using the CORRECT type starter bolts with the knurled shaft area...and NOT just a bolt. And sometimes it may take you looking really carefully when you are tightening these bolts because if your starter has the ability to twist...tighten it and see what it does and then if that does not work...loosen it back up and twist it in the other direction that little bit. And by 'twist' I am meaning that little bit if side to side movement that they can have.

Or it can be...which it is possible...you have bad flex plate that was not made correctly....but that would be a first for me.

DUB

 

Yes to all you follow up questions ( rear bracket in place, right shims, started with thinner and worked up in thickness, starter bolts do have nurelled ends, the flex plate is original to engine and starter matches).

I've been putting starters in for years as well and this one is a mind bender.

 

First off, are the starter and flywheel the same as before you removed/disassembled the engine? Bent starter bolts aren't common, but I'd check them as they will cause the starter to be misaligned. First off, the reason you have to use shims on a Chevy starter is because back in the day they weren't true and the starter teeth would bind on the high spots. It shouldn't take more than one or two shims to get it right. There were also different models of starters so hopefully you started off with the right style.

I suggest you remove the starter, obviously disconnect the battery, remove all the shims and the starter solenoid. With the solenoid off, reinstall the starter and manually pull the solenoid plunger to pull the gear into the flywheel. It should engage the flywheel teeth with a little gap between the teeth. I'm sure there's a spec, but probably .035" will do. If it binds you'll need to add shims until it has enough gap. The gap I'm writing about is the gap between the starter and flywheel teeth.

You only need to remove one starter bolt and loosen the other to add or remove shims. While you're at it, make sure that both the front and back has adequate clearance too. If the starter is wrong, or assembled wrong you'll have issues too. Once you clearances are good, reassemble it and test it.

 

As I was typing Dub added some good points too. The correct bolts will help to center the starter over the mounting holes.

 

All good stuff, the flex plate and starter are original to the engine. I have the original starter and it does the same after rebuild as the new replacement. I'll try the starter solenoid removal process tomorrow and report back.
Thanks everyone.

 

I understand completely.

Hopefully you get it to work.
DUB

 

The answer was I was a dumb a$$. I was putting the ground wire between the starter and block to use as a ground location. That one connection set off the alignment. It acted like a shim on one side.

 

I, for one, applaud you for having the cojones to admit to such a mistake and you are not alone by any stretch of the imagination. I wish i could remember all of the times I have done something similar.