Morris Minor Owners Club

Is the procedure for fitting a new ring on the flywheel like chisel off the old ring and bung the new one in the oven for an hour and slip it on quickly before it cools ??

roughly

When I did mine I cut through the old ring (can be done at an angle to accomodate the step im the rim of the flywheel) To get mine on we had to get the whole ring nearly cherry red! im not sure your oven will get that hot. It might help, putting the flywheel in the freezer as it will contract a tiny bit.

Clean up the faces of course - and yes max temp in the oven is supposed to be enough - but give it time in the oven to expand. Cherry red sounds way too much.

good to know (kingers crossed that I havnt changed the tempering)

Old school way is to heat the gear on a barbecue, I believe, assuming no access to an oxy actelene torch

Hello all,

it is not necessary to either cut the old ring or heat the new.

Put the flywheel on a solid base and drift off the old using a decent hammer and drift (2lb hammer is fine). Clean both the new ring and the flywheel register and gently ease the new ring on with a hammer, to get it started then drive it home with a drift. It can take a bit of patience and even tapping to get it to start all the way round but it will go on. The problem with flame heating is that is is all too easy to overheat the ring and soften the teeth (being as they are relatively small section and heat up quicker)

Alec

Hence the idea of gentle over-all heating in the oven - best done when domestic authorities are absent!
Never heard of it being done 'cold' before - but if you have done it Alec - and it didn't fall off later - then could be the way forward.

Hello BMCE,

I have, although on a Triumph flywheel, but that is bigger.

Alec

Easy wat to remove old ring is to drill a hole, then hammer and chisel at hole to split ring.

Hello Steve,

without damaging the flywheel? How do you know when you are through the ring and not drilling into the flywheel?

Alec

Measure it

And make sure you wear safety goggles.

But a small hole in the flywheel won't matter too much if you over-do it!

The BBQ method works great -- mine slipped on without any interference after a BBQ pre-heat. Although I am familiar with putting the other piece in the freezer, it was not at all necessary.
Nick
Lockport NY USA

I removed the ring off a scrap flywheel on another vehicle (Reliant Fox)and turned it around so the chamfer was suitable for an inerta starter as an experiment.
Propane torch heated it up enough to allow easy drifiting off and futher heat allowed easy reinstallation.
Obviously I don't recommend heating to remove normally but as I said this was a scrap flywheel used for "mocking up" puposes.
When cooling keep a hammer handy to gently tap the ring to ensure fully seated.
I reckon domestic oven would be hot enough for the new ring gear if I found a propane torch outside worked.

Paul Humphries

Well - an oven should go to 200C - which is plenty. Wear good gloves!!

For removal I drilled and ground with an angle grinder, then used a 2lb hammer to finish the job!
I used the oven for the starter ring when Lindsay was out SHHHHHH!
Also, the flywheel went into the freezer overnight disguised in a pizza box....
Ring dropped on to the flywheel with almost 1mm to spare - I was worried! All was fine though when the temps equalised.
One of the easier jobs!
Dom

Thats what we like to hear ! Job that goes as planned.

The oven didn't even smell of anything untoward afterwards which was a bonus!

I found fitting the ring gear on the flywheel impossible when just heated up in the oven. Had to put the ring gear very close to the grill to get it hot enough, it had then just expanded enough to fit on the flywheel you can see my pictures on my website http://www.morris-1000.co.uk/Engine%20U ... engine.htm