Flywheel removal

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72degrees
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Re: Flywheel removal

Post by 72degrees »

Oops.

Is it an early one with just two holes for the holding tool or later with three 'slots' and fins on the back?

I've just had a look at a later one I have on the shelf to see if you could somehow use a 'legged' puller but there is very little room to get behind it.

Not casting any doubts on the NLM tool (as they have always worked for me) but possibly source a different manufacturer puller?
Search Google for: 27+x+1.25+flywheel+puller&hl=en

You are getting the puller screwed absolutely home before trying to extract? Possibly rusty threads on the rotor centre stopping it going in fully?

Tapping on the end of the puller 'bolt' once very tight?

Soak as best you can in Plusgas for days (make a sort of cup with plasticine or even blu-tack to hold a good volume of the one true penetrating fluid) before the next attempt. Heat might help but difficult to get differential expansion of the steel centre/shaft unless a lorra, lorra heat and so a toasted stator. I've started to use an electric heat gun (plumbing etc.) rather than a naked flame and it's surprising how hot they can get things (hot enough to get Plusgas, or perhaps 'Shock 'n Unlock', vaporising when sprayed on (the shaft). It helped to get a recalcitrant clutch centre of my old Gilera - but no windings in danger in that scenario.

What MickeyMoto said or possibly other destructive techniques (a Dremel diamond cutting wheel and lots of patience ?) if all else fails.
mbmm350s
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Re: Flywheel removal

Post by mbmm350s »

Most of the advice is already on this thread but please make sure to remove the spring washer under the nut or the tool will not engage in the rotor threads fully.
Make sure the tool is tightened into the rotor the proper tool has flats on the sides of the outer part. Make sure the inner bolt is fully unscrewed when installing the tool.
If it will not pull off with a spanner, mine use normal 17 mm AF spanner then next is to use mallet on the end of the tool. You can alternate between tapping the bolt and putting pressure on the spanner. I have never had one that would not come off with a decent blow. Avoid hitting the rotor.
The previous responses have given some more drastic measures.
I once saw an engine which had lost the end of the crank as the numpty had tried to spin the rotor off by running the engine...
rotors are not too hard to find and can be remagnetised.
If you have the two hole flat rotor you can upgrade to the finned rotor.
once it is removed you will be able to check why it was difficult to remove.
all the best
Mark
'It must be a .....'
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Re: Flywheel removal

Post by 'It must be a .....' »

Hi, lubricating the puller bolt with grease makes a massive difference to the amount of force/pull you can get from the puller.
Again make sure the spring washer is removed and the puller is fully screwed into the rotor.

Good luck
acemorini
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Re: Flywheel removal

Post by acemorini »

On my 500 the fly wheel was rusted on solid as a result of being in a shed for twenty years, I used everything I could think of no movement at all, then a mechanic friend said fit the puller and tighten it up as tight as you can get it with out stripping the threads and apply heat, see if it will tighten anymore if not leave to cool and repeat, I did this about 4 times using a hot air gun to apply the heat and on the 4th time off it popped off, like every thing on this bike it took about 3 days to complete.
Regards Pete.
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Re: Flywheel removal

Post by EVguru »

I've only ever been defeated once by a flywheel and that one had to be ground off. The rivets were removed and the rotor taken off the hub. The hub was then ground away until it split with a bit of a bang. The tapers were as clean and perfect as I'd ever seen and had quite possibly been installed too tight.

I've encountered a stripped puller before, on the sport of the greatly missed Martin 'Realmart' Gelder. The flywheel threads were somewhat worn, so the puller was fighting a loosing battle.

You can find Martin's writeup here; http://www.realclassic.co.uk/morini06051101.html

I recall I later TIG welded up and recut the threads on that rotor.

Remember if you're hitting the puller bolt on the end, all that percussive force is being transmitted through the balls and races of the drive side main bearing.
That's why I like a tool that imparts a rotary impact, air or electric.

If you use heat to help break the taper, then the heat need to go in fast. You're trying to get the rotor hub to expand, whilst the crankshaft stays cold and expands as little as possible. If you don't heat fast enough, then you won't get enough temperature diference.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
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72degrees
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Re: Flywheel removal

Post by 72degrees »

EVguru wrote: Remember if you're hitting the puller bolt on the end, all that percussive force is being transmitted through the balls and races of the drive side main bearing.
That's why I like a tool that imparts a rotary impact, air or electric.

If you use heat to help break the taper, then the heat need to go in fast. You're trying to get the rotor hub to expand, whilst the crankshaft stays cold and expands as little as possible. If you don't heat fast enough, then you won't get enough temperature diference.
I did say 'tapping' not lamping - Engineer's feel ;) So you use an impact driver on the hex of the rotor puller?

Or you *may* be able to cool down the crank taper with freezing spray quickly, though I agree it doesn't work that well in this scenario as you can't get the spray on to just the shaft. It's great for getting needle roller outer races out alloy suspension linkages though. It might, with luck, just persuade a bit of release agent to reach the parts...

It helped when getting my Gilera clutch centre off. But what really worked (after several heat/release agent cycles) was a lump hammer on the outer ends of a two leg reversible puller which gave a crude slide hammer effect. Still axial load but I was getting desperate and I reckoned that hopefully the clutch studs (the puller was pulling on a thick alloy plate held on the hub by the four remaining unbroken ones) would probably fail before I did too much damage to the output bearing!
Lewes96
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Re: Flywheel removal

Post by Lewes96 »

Hmm, another puller stripped and another obtained. Is it worth trying a three legged puller together with the centre puller?
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72degrees
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Re: Flywheel removal

Post by 72degrees »

Lewes96 wrote:Hmm, another puller stripped and another obtained. Is it worth trying a three legged puller together with the centre puller?
I don't think any three legged puller is going to slot behind the rotor. So is it the external thread of the puller that is stripping? Evguru's welding dodge still relies on the internal threads of the welded on puller and of the puller bolt as far as I can see. May be time for the MIckeymoto nuclear option.

This is what I rigged up on the Gilera 175 clutch centre. The official puller replaces the pressure plate. I drilled a piece of engine plate thickness dural to fit the four remaining studs, with a hole for a two legged puller bolt to pass through. Tightened it mightily (until the ends of the plate were beginning to bend outwards) and then (after heat and shock 'n unlock) used a lump hammer *outwards' on the other ends of the puller legs. A picture is worth 1000 words. Nothing to attach the plate to on a Morini flywheel though, unless you made the plate of thick steel and welded it on.
175Clutch.JPG
175Clutch.JPG (188.44 KiB) Viewed 9094 times
Lewes96
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Re: Flywheel removal

Post by Lewes96 »

Yes it’s the threads on the puller (softer material) which are stripping. Have applied blowtorch sparingly over flywheel and leaving penetrating oil soaking with puller under tension. It is t budging and I don’t feel much like welding things on yet, but may get there!
acemorini
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Re: Flywheel removal

Post by acemorini »

Try using a hot air gun on the fly wheel the one I have has a very small nozzle that is designed for plastic welding, you can position the air into a very precise area on the fly wheel which I found helped. Where are you based ? If you are not to far from me you can borrow my hot air gun and give it a go.
Regards Pete.
Lewes96
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Re: Flywheel removal

Post by Lewes96 »

Thanks but have tried a hit air gun, albeit not with small nozzle. Looking at three legged pullers (to use in combination with the centre puller), I think one will fit. My only worry is whether it will distort the flywheel, given it is only alloy. Not sure if anyone has tried one?
acemorini
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Re: Flywheel removal

Post by acemorini »

I would have thought that it would be worth a go, if it wont come off you will have to cut it off so it will be scrap anyway.
Regards Pete.
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72degrees
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Re: Flywheel removal

Post by 72degrees »

I think you are at the 'nothing to lose' stage, so if you can get the puller 'hooks' behind the rotor securely enough that they won't slip off under pressure it is well worth a try.Have you got anything that you could use on that to achieve a 'slide hammer' effect?
Lewes96
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Re: Flywheel removal

Post by Lewes96 »

Not familiar with the ‘slide hammer’?
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Re: Flywheel removal

Post by 72degrees »

Lewes96 wrote:Not familiar with the ‘slide hammer’?
Usually deployed to remove blind bearings from cases (or dents from bodywork). So not tapping inwars on the puller, but outwards. I simulated the action by whacking a lump hammer outwards on 'hooks' of my two legged puller in my photo.

https://www.ebay.co.uk/itm/Silverline-3 ... 2632409643
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