Diagnosing Starter Pinion damage...
Thread Starter
Racer
Joined: Oct 2007
Posts: 270
Likes: 0
From: Chapel Hill NC
Diagnosing Starter Pinion damage...
I put in a new starter this weekend. 1977 manual.
The old one had teeth on the starter pinion that were rounded off at the ends.
What does this tell me? (there were no shims on the starter that I removed).
I did put half of a .015 shim on the outboard side of the starter... and I think it sounds better than with no shims at all.
Since this is my first starter replacement... and the new one certainly works... and as far as I know... sounds fine when starting and running... but I wanted to know if the old one needed shims and this is what caused the teeth to be worn down?
The old one had teeth on the starter pinion that were rounded off at the ends.
What does this tell me? (there were no shims on the starter that I removed).
I did put half of a .015 shim on the outboard side of the starter... and I think it sounds better than with no shims at all.
Since this is my first starter replacement... and the new one certainly works... and as far as I know... sounds fine when starting and running... but I wanted to know if the old one needed shims and this is what caused the teeth to be worn down?
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
you need either a ring gear if its a standard shift or a flex plate if a automatic....shims 'DO not help, only make it worse moving the starter away from the ring gear......
its easily diagnosed but you must remove the transmission to repair
its easily diagnosed but you must remove the transmission to repair
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
The leading edge of a 'correct' starter drive gear has beveled surfaces...so that it will engage with the ring gear smoothly. I'd be surprised if the new one didn't have that, also. If you remove the inspection cover from the bottom of the bell housing, you can "test" the engagement of the starter drive gear and the ring gear by disconnecting the power lug that runs from the solenoid to the starter. Do this by first disconnecting the positive battery cable, then removing the bolt connecting that power strip to the starter; and finally, putting an insulator between that lug and the starter connector.
Then, reconnect the battery and turn the ignition to "Start". As long as you hold the key in that position, the solenoid should force the drive gear to engage with the ring gear but the starter should not turn. That gear should freely engage, but not have excessive clearance between the faces of the gear teeth.
I couldn't find a recommended clearance between those gear teeth in the Chevrolet Chassis Service Manual, but I would think that it should not be much more than .010 inches (certainly less than .020"). If anyone else knows the correct gear lash spec, that would be helpful.
Then, reconnect the battery and turn the ignition to "Start". As long as you hold the key in that position, the solenoid should force the drive gear to engage with the ring gear but the starter should not turn. That gear should freely engage, but not have excessive clearance between the faces of the gear teeth.
I couldn't find a recommended clearance between those gear teeth in the Chevrolet Chassis Service Manual, but I would think that it should not be much more than .010 inches (certainly less than .020"). If anyone else knows the correct gear lash spec, that would be helpful.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
[QUOTE=
I couldn't find a recommended clearance between those gear teeth in the Chevrolet Chassis Service Manual, but I would think that it should not be much more than .010 inches (certainly less than .020"). If anyone else knows the correct gear lash spec, that would be helpful.[/QUOTE]
use a paper clip!
I couldn't find a recommended clearance between those gear teeth in the Chevrolet Chassis Service Manual, but I would think that it should not be much more than .010 inches (certainly less than .020"). If anyone else knows the correct gear lash spec, that would be helpful.[/QUOTE]
use a paper clip!
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I noticed something you said. starter shims go all the way across under both bolt. NOT just one like you mentioned. I work mostly on aftermarket mini starters. I have never really measured the tooth to ring gear gap. It's like "Why would you?"
You short the sel and the starter gear kicks out. You look and see how much tooth engagement you get. I even called a starter company and I was assured that anything over 50% was good.
With the least amount of shimming under both bolts. You fire the gear out and if has enough clearance to get more than 50% every time with out binding going on or binding coming off the ring gear you are good to go.
I have never chewed up a starter or ring gear and I do them a couple times a month. I do lots of clutch and tranny jobs
You short the sel and the starter gear kicks out. You look and see how much tooth engagement you get. I even called a starter company and I was assured that anything over 50% was good.
With the least amount of shimming under both bolts. You fire the gear out and if has enough clearance to get more than 50% every time with out binding going on or binding coming off the ring gear you are good to go.
I have never chewed up a starter or ring gear and I do them a couple times a month. I do lots of clutch and tranny jobs
Thread Starter
Racer
Joined: Oct 2007
Posts: 270
Likes: 0
From: Chapel Hill NC
Thanks!
I feel reassured about the installation. (starter is an OEM replacement)
I now have it installed with no shims. Now that I understand the mechanics of the starter a little better - I feel a bit more confident.
I hear a slight whine on start-up.. but that goes away quickly and I am not hearing anything offensive after that.
Maybe unrelated, but my idle is up a tad since the starter installation.
I now have it installed with no shims. Now that I understand the mechanics of the starter a little better - I feel a bit more confident.
I hear a slight whine on start-up.. but that goes away quickly and I am not hearing anything offensive after that.
Maybe unrelated, but my idle is up a tad since the starter installation.
