Page 1 of 1

Stubborn flywheel removal

Posted: 06 May 2017 17:39
by Sheikh
Any suggestions as to how to remove a flywheel that's been in place for 30 years?

I'm using a proper puller, threaded fully home into the flywheel. The screw has been tightened with all the force that a 11 stone weakling can manage and then given a sharp tap with a hammer.

I've tried applying some heat, though nervously on account of the coil insulation. Am now contemplating going the other way and using plumbers freezing spray.

What do you reckon? I don't want to get the grinder out unless I have to.

Thanks

Hugo

Re: Stubborn flywheel removal

Posted: 06 May 2017 18:35
by buzby
I always use an electric impact wrench on my bikes

http://www.clarketools.net/clarke-1000w ... AtLU8P8HAQ

Re: Stubborn flywheel removal

Posted: 06 May 2017 19:16
by 72degrees
If the threads are good and the puller is fully home are you using a breaker bar or similar on the puller screw for extra leverage?

Judicious heat (hair dyer?) followed quickly by freezing spray just on the shaft might help.

Re: Stubborn flywheel removal

Posted: 06 May 2017 19:39
by Ming
Easing oil, then tensioning the extractor as much as you dare and leave it under tension. Keep tapping it with a mallet from time to time and retensioning if it will go. Should give eventually.

Re: Stubborn flywheel removal

Posted: 06 May 2017 21:21
by SupermotoDave
Leave it under tension, perhaps periodically tap it rapidly with a hide or copper mallet or similar so it rings, and make sure when you leave it in the garage it is not pointed at an expensive item such as a car door lest it suddenly fly off.

David

Re: Stubborn flywheel removal

Posted: 06 May 2017 23:17
by 'It must be a .....'
Hi, release the puller then try lubricating the puller threads with grease it makes a big difference as the puller threads can lock due to friction.
Hope this helps, Ian

Re: Stubborn flywheel removal

Posted: 07 May 2017 09:57
by 2volts
eventually you will succeed and as mentioned above it will release suddenly and fly off, make sure you are standing to the side and not in the line of fire

pete

Re: Stubborn flywheel removal

Posted: 07 May 2017 11:33
by 72degrees
2volts wrote:eventually you will succeed and as mentioned above it will release suddenly and fly off, make sure you are standing to the side and not in the line of fire
pete
I strategically place a plastic bakers loaf tray in the drop zone.

Re: Stubborn flywheel removal

Posted: 07 May 2017 18:09
by Sheikh
Thanks for all suggestions and support.

I tried some 'Shock Freeze Release Spray'

I tried leaving it overnight with the puller tight

I tried a little bit more heat

I tried greasing the threads on the extractor screw

I tried a more substantial whack on the extractor screw

I tried another heave on the breaker bar, and another. And then felt that gentle give as the screw begins to shear.

Time to leave it for a while. And to get another flywheel puller.

Will keep you posted

Re: Stubborn flywheel removal

Posted: 07 May 2017 19:28
by EVguru
Hammering away on the end of the puller transmits the shocks directly to the drive side main bearing. You risk Brinelling the races.

Heat doesn't work unless you create a substantial temperature (and therefore expansion) differential. The hub has to heat up fast!

That may mean grinding off the rivet heads and pulling the body off the hub and then using Oxy-Acetylene or a MAPP gas torch, a propane torch may well not put the heat in fast enough.

You'd probably need to make up a papier-mache poultice to protect the stator, or use one of the proprietary products like Cold Front.

I must have done dozens of rotor removals and normally I find that the air impact wrench pops them straight off. I've had one failure and that required sacrificing the rotor hub, grinding it down until it cracked and released the tension. The taper was in perfect condition and perhaps it had been over tightened.

I use the air gun for tightening too, but know the tool, turn the torque down and watch the movement of the nut.

Re: Stubborn flywheel removal

Posted: 07 May 2017 21:24
by SupermotoDave
Tap the flywheel when under tension, not the puller.

David

Re: Stubborn flywheel removal

Posted: 16 Jul 2017 14:15
by Sheikh
Patience is a virtue. Or something like that. In frustration I left it for two months with the puller on tight, came to it again today, removed the puller, re-squirted it with freezing release spray and then put the puller back on it. It slid straight off with minimal effort.

Thanks for all the advice.