Fitting Starter ring gear

[DaveAlmey]

I thought this was going to be easy, but on reflection most of the restoration job has been an uphill battle for me.

Needed to replace the starter ring gear as it had a chipped tooth and the engine was in rebuild stage anyway so one was obtained from Sue Miller

Everything spotless, flywheel had been in the deep freezer for 10 days and the fan oven is on max (240C) ring gear cooked all afternoon (3 hours) and I was feeling very confident as out popped the flywheel quickly followed by the ring gear and it should just drop on! Wrong, not a hope of it slipping over.

Any experts on the subject any advice.

Thanks

Dave

[ppnelan]

I had the exactly same problem and melted the soles of my shoes after jumping up & down on it to try to get it to fit...

The solution was to use the oven grill instead of just the oven - the ring gear got hot enough to slip on nicely. This makes sense since it is very easy to burn food using the grill, but not so easy with the oven alone.

Matthew

[DaveAlmey]

Thanks Mathew,

Will try again, the proof will be in the pudding.

Thanks

Dave

[david.g.chapman]

I had one fitted last year. Believe it or not I took the flywheel and ring gear to Dovercourt Ford in Chelmsford and asked them to fit it. They did it for nothing during the day!

When you think about it, the job is so quick it sort of makes sense - a bit of light relief for the mechanics? I have always done well by turning up at the garage with the parts to be worked on and puppy dog eyes!

Anyway, you might be lucky as well if you don't want to DIY. It will only cost you the minimum time unit in labour anyway, even if they charge.

Dave Chapman.

[rgwitherell]

I heated the ring gear on the grill of a gas barbecue. Lifted it with two pair of tongs and it slipped onto the room temperature flywheel with no problem.. It was so loose it could actually rotated easily for a few seconds until it cooled down. I did not check the temperature but the thermometer never goes above 600F so I doubt it would get over the 1000F required to anneal the ring.

[elans3]

Same here, though in the grille part of the oven for about half an hour prior to fitting. Flywheel was in the freezer for a couple of days. It fell straight on, no clouting required, and was tight inside 30 secs. Wife wasn't pleased though........
elans3

[peterako]

Ahh....the memories

[type36lotus]

I brought mine to a local parts place which also has a machine shop. They heated it with a welding torch and just placed on the flywheel and let it cool. Charged me maybe $10. Well worth it even if they only spent 5 minutes to remove the old one and install the new one.

[SENC]

An old thread, but as I'm replacing mine thought a couple pictures might help others in the future to see the lip that requires the ring gear to he cut for removal.

flywheel lip

cut ring gear

[SENC]

Well, that was unsuccessful. First attempt with ring gear heated to 400 and it was not going over the lip. I then popped the flywheel in the freezer over night and heated the ring gear to 550 today. Was able to get it partially over 1 side, but no amount of coaxing would get it over the entire lip... and it certainly wasn't slipping on as others have reported. I suspect I could get it to fit if hotter, but understand I'm already pushing it over 500.

I've read there are a few variants with very slightly different ids 10" and fractionally over - has anyone fitted a new ring over this flywheel that can advise on the right id and source?

Flywheel 105E-6380C

[promotor]

10.048" should be the size / diameter of that flywheel. I don't think any Lotus used the 10.167" size that is available (to fit some late crossflows and pintos).

It usually takes two people to do the ring gears I've been involved in fitting - one to keep it in place while the other person hammers the gear on. And it's almost what I would call a brutalizing! They are not easy to do IF you don't want to take the ring gear beyond its safe heat limit.

[SENC]

10.048" should be the size / diameter of that flywheel. I don't think any Lotus used the 10.167" size that is available (to fit some late crossflows and pintos).

It usually takes two people to do the ring gears I've been involved in fitting - one to keep it in place while the other person hammers the gear on. And it's almost what I would call a brutalizing! They are not easy to do IF you don't want to take the ring gear beyond its safe heat limit.

Thanks Alistair, it may be time to get it on the bbq and/or apply some gas to it, and a little more brute force (though I did give it a few good wacks with a mallet and brass drift after the 2x4 method didn't work).

[h20hamelan]

have your flywheel in the freezer overnight too

[SENC]

Thanks for the encouragement - found another use for my grill. It took getting it up a little over 700 and a vigorous beating with a brass punch, but it is finally over the lip and on! Made me hungry, though, and earned an adult beverage.

[promotor]

Well done, good result there!