flywheel stuck!!!

[NW Drifter]

So far I've tried 2 1/2" impact wrenches one large air and 1 dewalt battery. Neither can get it as tight as I can with a 4' breaker bar. Once tight I heated with MAP gas for 10 mins, moving the torch around the center of flywheel. Still nothing. I can tell this puller I'm using with special grade 10.8 bolts is about to strip the center 3/4" bolt and is moving past vertical. I have hammered with w/ 6 lb sledge but I don't want to whack it anymore.

I'm about to give up and take it to a shop but I've allready bought the $125 belt.

What should I do?

[tarheel53]

It may be more than you want to go into - but a home made puller may be a good option. I used to mess with Austin Minis - the flywheel on a mini has a tapered fit onto the end of the crank. They were famous for almost welding themselves together - store bought pullers were useless. I made a puller using a piece of 3/4' plate with a 1 1/8" grade 8 bolt in the center ...... a nut welded to the underside of the plate accepted the bolt. Also drilled and tapped the flywheel to take 3 larger diameter (1/2" ) fine thread bolts that screwed into the flywheel face through holes in the puller. With this setup and a 4' long pipe slid over 1/2" drive pull handle - never had one refuse - but did involve a lot of cussing and banging on the center bolt after pulling it super tight.

[almetelo]

I had some trouble to remove the flyweel of my F100 and had sucess with a freezing spray

[gtreanto]

So far I've tried 2 1/2" impact wrenches one large air and 1 dewalt battery. Neither can get it as tight as I can with a 4' breaker bar. Once tight I heated with MAP gas for 10 mins, moving the torch around the center of flywheel. Still nothing. I can tell this puller I'm using with special grade 10.8 bolts is about to strip the center 3/4" bolt and is moving past vertical. I have hammered with w/ 6 lb sledge but I don't want to whack it anymore.

I'm about to give up and take it to a shop but I've allready bought the $125 belt.

What should I do?

My experience is MAP does not get hot enough. I always heat with Oxy Acetylene.. On difficult things I heat, let cool for a day and try again. I have never done a boat flywheel but on lawn mowers I have to tap the side while the puller is loaded. Need to free the taper. Not sure if boat cranks have a tapered shaft for the flywheel.

[panasonic]

I would not go at it with oxy/act torch unless you want to ruin your flywheel and/or the nice stator that sits underneath there. Lawn mower flywheels are cheap....outboard motor flywheels are very expensive...

Do you have a electronic supply store near you? If so pick up a can or two of super cold spray. It is non flammable. Gum remover is not.

Try this. Put the puller on again. Heat gently all around the shaft but not the shaft itself. Then hit the shaft with super cold spray. It may take several tries of heating and cooling. Or forget the heat and just try the cold spray on the shaft.

If that don't work then you will have to bring it to a shop and have them pull it.

[FabricGATOR]

So far I've tried 2 1/2" impact wrenches one large air and 1 dewalt battery. Neither can get it as tight as I can with a 4' breaker bar. Once tight I heated with MAP gas for 10 mins, moving the torch around the center of flywheel. Still nothing. I can tell this puller I'm using with special grade 10.8 bolts is about to strip the center 3/4" bolt and is moving past vertical. I have hammered with w/ 6 lb sledge but I don't want to whack it anymore.

I'm about to give up and take it to a shop but I've allready bought the $125 belt.

What should I do?

The flywheel is designed to be removed, so it really is not that daunting a task.

Most of the time, you bolt on the puller (it needs to be pretty straight and even) and apply moderate tension... like you said, with a breaker bar A 1/2" drive breaker bar with an 18" - 24" handle should do. It should never be so tight that there is any chance of stripping threads or stretching / breaking reasonably strong standard quality bolts.

Snug up the center bolt to apply tension and then hit that center bolt directly inline with a single stout strike with a 5 pound hammer... it should pop.


What should you do? I think maybe you should take it to a shop and let them install your belt for you before things get any worse. I also recommend that you stop using power tools.

[TownsendsFJR1300]

If the "freeze" doesn't work, IMO, bring it to the shop before you damage something expensive/ strip the flywheel threads, etc

Wacking hard on the puller which transfers directly to the crankshaft isn't the best thing for the main crankshaft bearings.

They can use your new belt, labor shouldn't be an hour, hour and a half.

Much cheaper than a destroyed flywheel / stator..

(I would ask how the shop will do the (proper tools) and won't be taking a 10
lb sledge to it. )

[panasonic]

Tony, can you take a picture of your set up? Maybe if we see it we could offer some better suggestions...

[TownsendsFJR1300]

Any updates??

[robert graham]

Wonder for the future if a dab of anti-seize compound on that taper would help for removal?....

[panasonic]

Wonder for the future if a dab of anti-seize compound on that taper would help for removal?....

Tapered shafts are not supposed to have any lubricants on them, that is why they hold so well and are hard to get off...very close metal to metal contact.

The wood drift key is there to align the flywheel in the proper orientation and to help it to stop spinning on the shaft. But most of the holding power comes from the taper itself.

[boscoe99]

Yep, no lube between the flywheel taper and the crank shaft taper. Woodruff key is just to align the parts. It should not be carrying any of the load.

I am now wondering if maybe the two tapers are not exactly the same so that there is an interference fit. Fairdeal, what say yee?

Doesn't every real man have one of these bad boys in his tool box?

[fairdeal]

Yep, no lube between the flywheel taper and the crank shaft taper. Woodruff key is just to align the parts. It should not be carrying any of the load.

I am now wondering if maybe the two tapers are not exactly the same so that there is an interference fit. Fairdeal, what say yee?

can't speak from actual knowledge,
but IMHO the closer the two tapers could be made to match, the greater the "interference fit" -
the maximal amount of contact between the surfaces of the two parts.

But I suspect the topic is ripe for fistfights even between the trained degreed engineers...

lubrication or no? I suspect it doesn't matter -
just as "dielectric grease" does NOT "insulate" electrical connections:
on a micro level, it just gets "squeezed out of the way" -
and there is metal-to-metal contact despite it.

which brings up surface finish:
should, or should not the tapered mating surfaces be "lapped" ?
would that improve hold - by maximizing contact area?
or reduce it - because "smoother surfaces will be slippery" ?

I sure don't know...

who has had the experience of "wringing" gauge blocks?

[fairdeal]

I am now wondering if maybe the two tapers are not exactly the same so that there is an interference fit. Fairdeal, what say yee?

No knowledge, no training on that - but seat-of-my-pants says
the closer the two tapers can be made to match,
the greater the "interference fit"- the maximum contact surface.

But I suspect this is another area for fistfights between the expert engineers...

and what about surface finish?
does "lapping" them increase the "grip" - because there is more metal-to-metal contact_
or only make the surfaces "slippery"?

having played with machinists gauge blocks - I don't have a guess...

and that IS a nice tool

[boscoe99]

I was thinking of a situation where the flywheel internal taper might be some number of degrees, say 45, and the crank shaft external taper might be a bit more in degrees. Say 46. The crank shaft would then wedge its way into the flywheel as it mated therewith.

But hell if I really know.

What I do know is that those two parts really stick together.