11 replies to this topic

[Southy]

I've pulled my engine out this weekend as I've had a few issue with the gearbox and I'm stuck at the first hurdle that I can't get the flywheel off.

It's an ultralite flywheel, I've got the puller on the flywheel fitted all square so it pulls evenly on the flywheel, I've tightened it up as far as I can by hand using a braker bar and also, 2 buzz gun's, I've tried knocking the puller to shock the flywheel off whilst under tension whilst continuing to tighen it up.

I've also had a large blow torch on the nose of the flywheel whilst hitting and buzzing the puller but it's still yet to budge.

I have now left the puller fitted over the weekend to see if that helps but I doubt it will, is there any other suggestions as to what I can do to relase it?

Would it make any difference that the crank has been heat treated also?

[Kerrin]

As far as I can tell there is a miss match of materials when using a steel flywheel on a cast iron crank which can cause the taper to fret and weld itself to the flywheel.

I can't offer any more solutions for removal but have avoided fitting a steel flywheel myself for this reason.

[L400RAS]

Did you remember to remove the keywed washer from the crank nose before fitting the puller?

Some flys take days / 1 week of tension, and then they just fall off on their own overnight! - put some soft blankets etc where the flywheel will fall off, and dont put anything expensive near the engine while its all under tension.

Edited by L400RAS, 13 February 2011 - 01:46 PM.

[Cooper-202S]

Unfortunatly patience is the best option here,
keep tightening it over the course of this week .
then try some more heat next week end.
If you can lay your hands on an old co2 fire extinguisher I have had some success with freezing the end of the crank while heating the fly wheel boss.
as others have stated they do just pop off for no apparent reason.

[bmcecosse]

Try to avoid the heat if you can. Shocks are likely to work best. Bang the bolt on the puller - and the plate itself to make it 'ring'.

[Southy]

Thank's for your advice people, will keep having a bash at it all this week and keep gunning it up, out of all the engines I've stripped I have only come across one other flywheel which has failed to come off with the above method's I've used and that was on an Mpi and the flywheel was miles out of balance so had fretted the end of the crank and welded itself on.

Would it be advisable to use a long ally drift through the starter hole and knock it that way whilst someone tightens the puller some more?
I have an old co2 fire extinguisher in the garage, was just about to throw it out this weekend....good job I kept it Will give that a try aswell as a last resort.

[valve bounce]

what ive done before is take the keyed washer out the screw the big bolt about half way back in and wind the puller up as tight as posible, then try and wind the big flywheel bolt out with a spanner this has worked for me a couple of times. if that dosnt work then hit the end of the puller and if all else fails put abit of tube or box section throught the starter hole and really hit it, turn 1/3 then repeat then turn a 1/3 again and hit it. other than that i dont really know this methord has alway worked for me.

before i bought a puller i just hit the flywheel throught the starter hole with a big hammer and that amlost always worked

[Cooperman]

It took me 3 weeks to get a flywheel off last October. I've never had one so stubborn.
I broke one puller centre bolt and was worried about the other 3 puller bolts so changed then for very high tensile ones.
I tightened it a bit every few days, heated it up with a butane torch, hit it with a lump hammer on the puller bolt head, tightened it a bit more, used an air gun, etc, etc. In the end I bought a can of 'Arctic Spray' which plumbers use. I heated it up with the torch and got it really hot, then quickly quenched it with very cold water, then froze it using the complete spray can, then hit it once more as hard as I could and, bingo, off it popped. The taper was fine both on crank and flywheel.
I did get very close to taking the angle grinder to it, but that risks scrapping the crank in addition definately having to replace the flywheel.

[Spannermanal]

I had the same problem yesterday afternoon. Flywheel wouldn't come off, even with heat. In the end, I tightened it right up with the puller and then hit the flywheel through the starter opening, rotating the crank so that it cam off evenly. After a couple of good whacks... success. Good luck with your efforts.

[Cooperman]

I had the same problem yesterday afternoon. Flywheel wouldn't come off, even with heat. In the end, I tightened it right up with the puller and then hit the flywheel through the starter opening, rotating the crank so that it cam off evenly. After a couple of good whacks... success. Good luck with your efforts.

You should never try to remove the flywheel by turning and hitting as the primary gear 'C'-washer could drop out and terminally jam the flywheel. The C-washer is fitted from the top of the crank downwars with 1 & 4 on TDC, so that is the position the crank should be in when it is 'pulled'. However, if you think it could have been fitted upside down, have 1 & 4 halfway between TDC & BDC.

[Southy]

The flywheel finally gave way today after bing under tension for 4 day's.

Went to it this morning and got another 1/4 a turn with the buzz gun and after a few more smacks' still didn't give way.
Managed to find one of our more powerfull buzz guns and once again got another 1/4 a turn on it, few smack's with the hammer still didn't budge, got out the bigger hammer and after a few hard blows off it popped.

No damage to the flywheel or the crank tail so I'm happy so thanks for all your suggestions

[Cooperman]

The flywheel finally gave way today after bing under tension for 4 day's.

Went to it this morning and got another 1/4 a turn with the buzz gun and after a few more smacks' still didn't give way.
Managed to find one of our more powerfull buzz guns and once again got another 1/4 a turn on it, few smack's with the hammer still didn't budge, got out the bigger hammer and after a few hard blows off it popped.

No damage to the flywheel or the crank tail so I'm happy so thanks for all your suggestions

Well done, that man!