Do I need to replace the flywheel?

I've had my 1960 CJ6 for a few months and from the beginning the starter grinds about half the time I try to start it. I replaced the starter and the battery and battery cables but it still grinds. The flywheel doesn't look that bad. No missing teeth all the way around and the wear is less than half the depth of a tooth on the worst tooth. I also measured the distance between the front of the flywheel and the bell housing and it's consistent all the way around and matches up nicely with a measurement of the starter with the bendix fully extended. What could it be?

 

Half a tooth missing is way too much. There should be a smooth chamfer to the teeth where the starter drive engages as the chamfer helps with engagement. The teeth should be pretty much fully intact.
Is the starter drive the right tooth count for the ring gear? Was that checked when replaced?

 

I had the original starter before and I was sure to get a starter with the same tooth count when I got an aftermarket one. I know nearly half a tooth missing on the worst tooth isn't ideal but will that cause grinding in 1/3 start attempts? All I'm saying is it will be a drag if I have the flywheel replaced and it still grinds. It can't be cheap to have that work done.

 

You probably don't need to replace the flywheel. Worst case you need to replace the ring gear on the flywheel. I would start with the starter (pun) by checking it out. It may not be disengaging properly.

Changing the ring gear is not that tough, but pulling the flywheel is a PITA.

 

Generally an engine comes to rest in specific spots when shut off. Those spots are generally where the starter engages the ring gear over and over. So there is the potential if the engine stops in that specific spot at certain time the starter drive will engage those (that) specific teeth (tooth) and pretty consistent intervals. If that or those teeth is are damaged then that could cause the symptoms you are experiencing.

 

That is interesting. Why would that be? Just wondering. WCP

 

Lowest energy is the spots in rotation between compression stroke on any cylinder. Tends to stop there. Stopping near the peak of a compression stroke stores potential energy; thus it's "downhill" to the spots furthest from a compression stroke.

 

I've tried two starters so I've checked them out carefully. Do you mean it may not be engaging properly? I'm not sure how disengagement relates.

Are you saying I can change the ring gear without pulling the flywheel?

 

I had always heard the same. Also that the amount of wear you say you have on the flywheel is excessive and could easily lead to starter engagement problems.

Once the flywheel is exposed, it's easy to remove it. Replacing the ring gear while the flywheel is still bolted to the crank would likely approach magic or at least engineering marvel status.

I'd bet a dozen guys on the forum could hook you up with a stock F134 flywheel

 

I don't think I have the tools (at least) to drop the engine or transmission to access the flywheel. What should I expect to pay for that?

 

It probably would be cheaper to buy an engine hoist than to pay someone to do it.. If you are comfortable doing it

 

you can remove the ring gear and put it back on in a different "clocked" position so it won't hit those bad teeth and you can flip it over to buy you time if you cannot fix it right the first time. have you tried shimming the starter? you can rent an engine hoist from a rental store in your town to lessen the cost too.

 

I think shimming the starter would only make it worse since the Bendix gear wouldn't be able to reach as much of the ring gear tooth.

 

What engine do you have? I believe some require shim adjustments to the starter (although I know the F-head does not).

 

On my engine (V6) the ring gear had 3 spots that were pretty worn and the starter would grind sometimes. I pulled the flywheel off (after dropping the tcase and trans) and pulled/pried the ring gear off of the flywheel. That part was easier than I thought it would be. I then heated the ring gear up in the oven (wife went to town for something so I could sneak it in to the kitchen) and dropped the ring gear back on to the flywheel but flipped over from the way it came off. This process was much easier than I thought it would be. It's been fine since (about 4 years ago).

 

Here's a video showing how to change the ring gear on the fly wheel if you go the route of doing it yourself.



I had this done to my flywheel when I had the engine out. Reused the ring gear (just flipped it over).

 

Very interesting video, I have never heard of shimming the flywheel before, but have rotated the ring gear a few times. I had my flywheel turned just to clean it up, it didn't need much was not burnt just rusty and had a pattern on it from the clutch, which still had some miles left before it would be down to the rivets. Thanks for the video, 55 Willys

 

Would it be easier to drop the transmission or engine to get at the flywheel?

 

drop transfer case and transmission.

 

Do I need special tools for that? Are they very heavy?