31 replies to this topic

[Dan]

This:

When removing one from mine I tightened the flywheel, then with the starter motor out hit the rear of the flywheel with a drift a few times, turned a bit, and repeated, tightening the puller when possible, eventually came off, but was hard work!

is the best way to cause this:

Flywheels get hairline cracks very easily and if yours gets one it will shatter at road speeds, this essentially means a fairly large explosion in the engine bay.

No it's not just a myth or scaremongering, quite a few of our members have had this happen to them after smacking their flywheels.

If you are going to lap your crank, don't do it very much. All you do when lapping a taper is chase the taper further up the shaft it is on. If the flywheel moves much further up the shaft than it already is it gets too close to the oil seal and the back of the transfer chest and too far from the clutch release. It will make the flywheel fit better but be careful. As for making it just fall off later, the better the taper fits the more it will lock up! It's the taper that holds the flywheel on, not the bolt.

Edited by Dan, 08 January 2008 - 01:07 PM.

[minimender]

This:

When removing one from mine I tightened the flywheel, then with the starter motor out hit the rear of the flywheel with a drift a few times, turned a bit, and repeated, tightening the puller when possible, eventually came off, but was hard work!

is the best way to cause this:

Flywheels get hairline cracks very easily and if yours gets one it will shatter at road speeds, this essentially means a fairly large explosion in the engine bay.

No it's not just a myth or scaremongering, quite a few of our members have had this happen to them after smacking their flywheels.

If you are going to lap your crank, don't do it very much. All you do when lapping a taper is chase the taper further up the shaft it is on. If the flywheel moves much further up the shaft than it already is it gets too close to the oil seal and the back of the transfer chest and too far from the clutch release. It will make the flywheel fit better but be careful. As for making it just fall off later, the better the taper fits the more it will lock up! It's the taper that holds the flywheel on, not the bolt.

I agree with the following reservations;-
To damage your crank by lapping wth valve grinding paste you would be there all day spinning it back and to.
The better the taper and fit the less the flywheel is going to move on the crank and cause damage and difficult removal.

I have fitted and removed flywheels literally hundreds of times over the years and some stick fast even after just a few weeks and some come off before the puller is fully tightened. The cranks that I have personally fitted and removed later have been torqued up correctly etc., it just is that some are easier than others to remove.
The cranks that I have lapped on for serious engine rebuilds rather than just testing have always come off easy so you pays your money and you takes your choice.

I personally have not known any one who has had a flywheel break up but I have heard that it can happen so best be on the safe side I suppose.
I always lap the flywheel on nowadays for job satisfaction.

[Tomf]

its not budging ill have another crack at it tomorrow, iv left the puller on for the night. ill get a blow torch at it and see if dat makes a difference.

[998dave]

When removing one from mine I tightened the flywheel, then with the starter motor out hit the rear of the flywheel with a drift a few times, turned a bit, and repeated, tightening the puller when possible, eventually came off, but was hard work!

is the best way to cause this:

Flywheels get hairline cracks very easily and if yours gets one it will shatter at road speeds, this essentially means a fairly large explosion in the engine bay.

No it's not just a myth or scaremongering, quite a few of our members have had this happen to them after smacking their flywheels.

Possibly, but as TomF said he was fitting a lightened flywheel I imagine he won't be that bothered about the old one...? I wouldn't have suggested it otherwise...

Dave

[Tomf]

yea i dont mind if it cracks to be honest as it will be being changed. ill go down the garage in a bit and have another go.

[Tomf]

This still isnt coming off, had anyone else got any tips? iv tightened it up with a breaker bar, as tight as i possibly can, (jumping on the breaker bar) Iv tried hitting it with various different hammers, heating it up then hitting it with a hammer, heating up up then throwing cold water on it. This really doesnt want to come off.

Had anyone got any other tips?

[minimender]

I have known people who have had to scrap cranks because the flywheel has welded itself on so if it wont come off you wont be the first

Look at it and make sure you are doing everything right, make sure nothing is stopping the flywheel from parting with the crank. then have another go, take the puller off and try it another way (turn it to next holes.)
Make sure the puller bolts that screw into the flywheel are screwed in absolutely even turn by turn. put the small protecter thing that the big bolt of the puller screws up against in the middle to protect the threads in the crank and try again.
As it tightens whack the flywheel through the starter hole using a piece of 3x2 and a BIG hammer and then turn the flywheel 1/4 turn and whack again, keep doing this and tightening the big nut a little at a time.

best of luck mate, I've been there

[Big_Adam]

If you don't want to save the flywheel and it's the stock cast one then you can cher-chunk it with a chisel and split the thing in half.

[rozzer!]

did you remove the woodruff key first? or is this just a verto thing? i did this and spent ages head scratching! before i realised what i had done!

[minimender]

Take a lot of work and it still wouldn't split the flywheel with a chisel in my opinion, I've given some flywheels a right pasting with a lump hammer to get 'em off ( if it breaks it breaks ) and then used them again because they have been allright.
If it rings when you tap it with a hammer it will be OK.
Perhaps flywheels were better made in the 60s ,70s, and 80s because I have never had any trouble with them and if anyone should have had one break up or explode them it was me.

Problem is that if the flywheel is slightly loose on the crank (unoticable play) then heat is generated and the crank and flywheel can weld themselves together. That would be an extreme case but it has happened to a friend of mine.

Just hope it comes off for him

[Globule]

My method is to tighten the puller bolt as much as possible with a long 1/2" breaker bar and suitable socket.

Dont use cheap ones, snapped a breaker bar doing this to an old beetle engine!

*or dont use a really long scaffold pole and a rather weighty nearby person*

Edited by Globule, 21 January 2008 - 09:28 PM.

[Tomf]

im just goint to try and hit it as hard as i can and it it comes of bonus, if it cracks and comes off bonus lol. I just want it off now.

[Globule]

Be careful, clearly its well held so will probably fly off/shatter and i wouldnt like to be the one standing behind that

[Tomf]

lol yea ill put a towel over it and strap it up tight or something similar so it doesnt go everywhere.

[alexcrosse]

lmao, get a huge hammer and really wack it, carry on what ur doin. Giv it a couple more days before looking for another crank! lol.

I tell you what though, its gonna make one hell of a fkin bang when it comes off considering the energy uve been puttin into it!