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reversing the ring gear

3341 Views 12 Replies 3 Participants Last post by  Gordon Raymond
I recently sent my 1600 flywheel into the machine shop for resurfacing and on the advice of a good mechanic friend had the ring gear"reversed" because the teeth were a bit chewed up. Well now everything is together and the starter seems to be hanging up on the unworn gears. So much so that I don't think the starter is fully disengaging on start up. There is a very loud wining noise coming from the starter - at this point I am not positive.
If the rest of the car was together I would push start it without the starter to confirm this - but too much is unassembled at this point.
thoughts anyone?tia
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Oh dear!

Big mistake:eek:. The NEW 1600 ring gear I have in my hand has a definate angled rake cut into the teeth from the "correct starter drive gear" side:eek:. To flip the ring gear over, the teeth are square, so the starter pinion won't be pushed back on start up:(. I do believe you will shortly trash your starter:mad:. Ask your mechanic friend to re evaluate the ring gear philosophy:rolleyes:. sorry for the bad news. :DGordon Raymond
thanks gordon much appreciated--well I was hoping for better news - i guess i get to practice taking my transmission out again..........I guess 1600 ring gears are available new?
It's interesting to note that an engine will stop in the same place some 90% of the time. This is why the ring gear teeth can wear mostly in one location. A solution used successfully many times over is to remove the ring gear, rotate it a few dozen degrees in either direction and reinstall it. This will expose a 'fresh' set of teeth to the starter drive.
ok second thoughts
Any possibility of modifying the starter drive gear to work with the reversed ring gear?
I am trying hard to meet a deadline for a vintage race event and this will really set me back...
Ring gears, starters and starter drives

Hi Ray,
The modifications to the bendix drive would be extensive, though I have done it for a Chrysler Hemi application with a 24 V starter. It was largely a matter of trial and error and very expensive:eek:. The hemi ran enough static advance (drag engine) and compression to break teeth off the ring gear on kick back when starting:rolleyes:. First came the custom ring ring gear with straight teeth to go with the custom 24 V armature in the starter, then hand ground and hardened double round teeth on the starter pinion with about a dozen different springs of different compression to try to get it to release:mad:. Eventually we found a combination that worked, but not before blowing up more than one custom starter:p. On kick back this engine could break the starter base and the web at the back of the block. It was NOT fun testing.:)eek::eek::eek::cool:)
For the time and effort involved, your best bet is a new (or newer used)
starter drive as yours is probably damaged by now, and another new or used ring gear correctly installed. The new ring gears are about $100 and used good starters are available as well. Problem solved, never have to deal with it again;)!
Papajam is also very correct. I am not sure why, but all piston engines, even radial aircraft, seem to stop in the same position on shut down. The greater the number of cylinders, the closer to the EXACT same position:confused:! Torn up ring gears in V12 Ferrari's are always in the same 1 to 2 inch area!
When ring gears show damage over a large part of the ring it's a sure sign of a VERY bad starter drive that is tearing it up not just on engagement, but on turning the ring. If you need sources for parts let me know. :DGordon Raymond
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OK -

NEW ring gear installed correctly - everything buttoned up - start the car -
Starter is still hanging up!
removed starter and tested it - seems pretty weak but it springs back OK.
I probably cooked it when i ran the engine
Looking at the new ring gear through the starter opening reveals slight wear on the new ring gear on all the teeth.
Seems to me perhaps the starter needs a spacer? Although I never needed one before - what else could be happening here? advice anyone..?
Starter problem? Can you post a picture of the wear on the new ring gear?
Very likely the starter is history after being spun by the engine with the old gear, though it could be the bendix drive is messed up somehow. From your note, it sounds like the starter pinion is too deep into the ring, correct? If you know of someone with a spare good starter, un installed, you could compare. I believe Centerline has a rebuilding service for these. What ever shop they use has probably seen a bunch. Perhaps they could advise on the critican dimension between the starter housing boss and extended pinion gear via E-mail? Worth a try if you have no local spare.
Best, Gordon Raymond
thanks gordon

I think I will try to find the dimension from the housing to the extended pinion gear.
Perhaps someone has a two bolt starter around and could measure it?
Hi Ray,
I have a new (!) one in my shop somewhere. I'll try locating and measuring it for you this afternoon.
Gordon Raymond
thanks gordon-

I had the starter looked at by my local auto-electric man. He cleaned it up -new brushes- checked out the bendix and drive gear and thought it looked pretty good.
I measured the distance from the ring gear to the plate on the flywheel - then measured the starter gear to the outside plate on the starter. It looked like a few milimeters clearance between the two.
Installed starter - works fine!
Can't really explain it perhaps the bendix was just hanging up from the old ring gear?
thanks for all your help - and the source for the ring gear ...
Glad it all worked out! :D

Thought you'd like to know though that your starter does not have a Bendix. Bendix drives work on the principle of inertia and a threaded shaft to engage the drive gear. These drives were phased out, at least on most automotive applications, by the early 1960s. They were replaced by the over-running clutch type (sprag clutch) starter drives currently in use today.
Papajan is correct as always, but doesn't Bendix drive have a nicer ring to it than Sprag Clutch:rolleyes:? Particularly for us older guys. "I gotta go fix my Sprag Clutch now:(". Or " I do believe my Bendix Drive may need some attention:)" Hummm?
Any way, I'm glad all is ok. I'm still searching for that NOS Bosch unit with it's Sprag Clutch:cool:. Best, :DGordon Raymond
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