Cat 943 1981 opinion on the flywheel

That needs a new flywheel ring gear as well as starter pinion. Your not going to get proper engagement unless you change both. Also need to look into a new or rebuilt starter as it appears to be dragging and not providing smooth engagement/disengagement. I'd suspect a sticking solenoid first or some one tried to engage the starter while engine was running.

Hello
The ring gear is not all like that.
I carefully rotated the flywheel 360 degrees and checked all the teeth. Most of them are in good condition.
It should be noted that in these bad conditions the vehicle turned on after the 2nd attempt.
The starter pinion is badly damaged.
I have decided to replace the complete (new) starter motor.
I did not understand a thing, the pinion engages in the first piece of the crown or enters all? if so there is hope of not replacing the crown.
And then to replace the crown you have to remove the engine, right?
Thanks Old Magnet

It should engage fully ideally. The bevels let it lead in more easily. Yes you will likely need to remove the engine

It is typical to have a wear pattern where only some teeth are affected on the flywheel as engines commonly come to rest at the same general location when shut down. You need mating tooth profiles to get smooth engagement so having a good ring gear is required.
A common trick when you have bad flywheel teeth is to roll the engine to where there is a good set of teeth for the starter to engage but that's only a temporary solution.

Ok
i think i will try to replace the starter motor. Let's see how it goes .

It is possible to re shape the flywheel ring gear teeth with a small grinder being careful not to get any grinding dust into the flywheel housing --stuff the opening with rag and magnets to catch the metal dust--been the done that--simply copy the undamaged tooth shape as best you can--any new bevel edge will help especially with a new starter pinion.

As Om said, engines like to stop at one cylinder most of the time so you can also move the ring gear 1/3 of a turn to expose undamaged teeth for the new starter to engage smoothly into.

Cheers,
Eddie B.

OM & edb-

Can the ring gear be removed, reversed, replaced and, if necessary, the teeth beveled? Just curious.

Thanks, Daron

It is rather difficult to get the proper gear tooth shape when touching one up as the gear tooth is precisely designed to give the teeth a rolling action with very little slippage. Couldn't tell for sure if the ring gear is toast from the photos as to what was damage and what was due to the lighting and reflections. Me being a farmer and often having to just make something work although not perfect you are probably on the right track to replace the starter and see how it works. If the Ring Gear needs replacing, go the way OM said and replace the Ring Gear and the starter drive so they are both new and should then last a long time. [attachment=61457]gears 2.jpg[/attachment] [attachment=61458]gears.gif[/attachment] [attachment=61457]gears 2.jpg[/attachment]