Ring Gear Replacement.

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Ring Gear Replacement.

Post by tgreening » Wed Apr 29, 2020 9:36 pm

Slowly making my way through a list of things that need to be addressed. My nest big one will be starter gear grind. I am going to assume the ring gear teeth and possibly starter gear are worn so...

I’m good with pulling the tranny, supporting engine and that biz, but I’ve never actually r&r’d a ring gear from a flywheel.

Just flying by the seat of my pants I’d take a cut off wheel and carefully split the gear. Probably get it close and try busting it with a hammer/chisel.

Clean surfaces. Then I’d heat the ring gear to whatever I can get away with in the wife’s oven while she isn’t looking, because I’m going to assume it’s a shrink fit, and then drop it on. Reassemble.

In the ballpark or no?


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Re: Ring Gear Replacement.

Post by Hotzenplotz » Thu Apr 30, 2020 1:12 pm

I had that issue some years ago


The ring on the flywheel was partially worn. Sometimes the starter hit a tooth and turned the engine, often it spun free.

I removed the gearbox, took off the flywheel and it was easy to get the gear ring off. I put the flywheel on a supporting block of wood, a sharp chisel and went round the flywheel sliding the gear ring down.

Installing the hew one was easy. I put the flywheel into the freezer to about -25°C and the gear ring into the oven at +150°C. The gear ring fell over the flywheel, a cloud of steam went up and the gear ring sat in position and is there still today....
The factory manual insists on getting new bolts to mount the flywheel on the crankshaft, as these bolts need to be stretched.
My Pinz has NEVER been with any army

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