Update...... installed an 0.020 shim and all is right with the world......thanks to all that responded with thoughts and ideas Sent from my iPhone using H.A.M.B.
There aren't two different ways to ensure proper gear engagement between ring gear and starter gear. There's no relationship between how far away the starter gear is from the flywheel gear, and how the two gears mesh. The starter gear could be 1/8" away, or 1/2" away, and it wont affect how the two mesh. Only way to insure the starter gear and ring gear mesh properly is to set how deep the gears engagement is. So shimming will make the depth more or less, depending on which side you put the shims under the starter. Put the shims on the block side between starter and mounting surface and it closes the gap and makes the engagement tighter. Put the shim on the outside away from the engine block, and it opens up the gap and loosens engagement or mesh.
I think you are misunderstanding me....took this directly off a GM website showing method A and method B....there was also a method C that involves painting the spur gear to check for proper alignment.
Don't want to Hi-Jack this thread, but need a quick answer. Like most of you, I've been replacing SBC starters, since I could drive. But helping friend, with his Hot Rod. '47 Ford with a 1970 Impala 350/350 combo. Power-Master starter actually slipped on the flywheel, so swapped in an Autozone example(reman), supposedly made for the Impala year and engine. Whined like my wife in the morning!!! Yikes!! LOL Pulled the Bendix out to examine clearance(did not measure) seemed ok to add shims, which I did. After adding 3 thin shims, it still makes a horrible noise. Yes, all the pieces appear to be in good condition, based on my 40+ years of experience. And yes, it has the front support bracket. Going to look at that clearance number tonight after work, using an 1/8" allen wrench. Thanks JT
Probably just needs shimmed to get it right. If not using the proper style starter bolts, shimming may not correct it. I've seen this more than once.
Ha! My former neighbor was a '69 Camaro pilot, he replaced a starter in that Bowtie beast and it howled like a Culver City quickie in a metal phone booth. I walked over, gave him 2 shims from my 'starter parts shelf', he shimmed it, and I went back home. Police Story was on...
Is the dust cover on between the bell housing and the engine block? it adds about 1/16 inch of space, also loosen and retighten the starter if not. spacing is everything!
Appreciate the advice, Fellas. Removed all shims, last night and took measurement, using 1/8" allen wrench, per instructions. It's actually a bit on the loose side. And still a bit noisy. Q: anyone ever milled off the nose cone like .010"?? (top mounting surface) to get it closer??? At that point, could always add a shim to make it perfect. Always striving for perfection. Thanks. JT
Yes, shimming just the outboard bolt increases mesh/decreases clearance. It swings the starter into the ring gear deeper. shim both, starter moves away, ...shim just outer, sterter gear moves in closer
I have a new Delco starter....the old starter has 11 teeth gear this new one has 9 teeth....the paperwork says the new starter works with either 153 or 168 tooth ring gear....it also says the 9 tooth is interchangeable with 11 tooth.....how can this possibly be true.
^^^^^ https://khkgears.net/new/gear_knowledge/gear_technical_reference/calculation_gear_dimensions.html
so the shape of the teeth makes the difference?.....interesting, thats why I always come here first...this is my first SBC so I'm struggling with the whole starter issues.....never had a problem with Mopar stuff.
There's actually a much easier answer. The center line of the armature/bendix isn't in the same location.
both starters have exact same shaft centerline measured from bolt hole to block mating surface and both shafts mic out exactly the same.