Thread: Flywheel ring gear

Replacing a ring gear is a simple operation. Many workshops used to do this as a routine operation. You just need to find one that still is prepared to do it.

All that is required is to remove the old one by splitting it, heat the new one in an oil bath, and drop it on the flywheel. If you can get a new ring, the rest is pretty easy. And hard to screw up.

Originally Posted by JDNSW

Replacing a ring gear is a simple operation. Many workshops used to do this as a routine operation. You just need to find one that still is prepared to do it.

All that is required is to remove the old one by splitting it, heat the new one in an oil bath, and drop it on the flywheel. If you can get a new ring, the rest is pretty easy. And hard to screw up.

X2. And if you can't find a mechanic who'll do it any halfway competent fitter could do it if you don't want to take it on yourself.

Originally Posted by JDNSW

Replacing a ring gear is a simple operation. Many workshops used to do this as a routine operation. You just need to find one that still is prepared to do it.

All that is required is to remove the old one by splitting it, heat the new one in an oil bath, and drop it on the flywheel. If you can get a new ring, the rest is pretty easy. And hard to screw up.

John, is there a reason for the oil bath?? Or would popping it in the oven do the job??

Originally Posted by JDNSW

Replacing a ring gear is a simple operation. Many workshops used to do this as a routine operation. You just need to find one that still is prepared to do it.

All that is required is to remove the old one by splitting it, heat the new one in an oil bath, and drop it on the flywheel. If you can get a new ring, the rest is pretty easy. And hard to screw up.

When I worked for BMC, Leyland, JRA we used to just place them on 4 bricks & heat with Oxy acetylene torch running the flame around the circumference until the paint marking on the ring gear changed colour then pick it up with a pair of multigrips & drop it on making sure it was on the correct way for the Bendix drive to engage.

I installed one on a flywheel made for the C240 Isuzu fitted to my Series III.
Heated the ring gear in a hooded BBQ.

Isuzu C240 powered Series 3

As mentioned by JDNSW, the old one needs to be split to remove.

Colin

Originally Posted by W&KO

John, is there a reason for the oil bath?? Or would popping it in the oven do the job??

It's just to ensure even expansion. So an oven, or careful use of a torch, would do.

As above - the oil bath ensures even heating and avoids any possibility of heating it enough to affect the heat treatment of the ring gear.

The ring gear needs to be heated evenly, so that it expands evenly, as it will be hard to get on if it is not circular. To do this, it also wants to be heated fairly slowly, and in an environment that is the same all over. A fan forced oven can probably do this, but I would not trust one that isn't - mine for example is good at burning one side of cakes!

While it is possible to do it with an oxy flame, a lot of skill is needed to avoid overheating and getting it evenly heated.

So, were the 1.6 flywheels one piece including teeth, or are the teeth always on a ring that gets fitted to the centre. I had a look last night and I cannot see any seam or join whatsoever.