Stihl 045 Flywheel

[RobertTX]

I am working on a Stihl 045 and cannot get the flywheel off. I am using a steering wheel puller which has successfully removed flywheel from other 045 and 056 saws. I think this one may have some rust under it. The flywheel drags on the coil as it turns so there may be rust under the flywheel hub. Any ideas? I have tried using heat gun but afraid to get too aggressive. Also tried whacking the bolt on the puller with no success.
I am trying to buy the Stihl 1107 890 4500 puller if anyone has one they want to let go. Thanks for your help.

 

[hotshot]

Keep it soaking in penetrating oil & hit on the puller center bolt while it’s fully tightened. Wait a few days & try it again, 40 years is a long time. It will come off, & sound like a shotgun report when it does.

This guy likely has your Stihl 1107 890 4500 puller kit, but hard to get ahold of him. Also sells used Stihl parts on fleabay.

https://m.facebook.com/CheapChainsawParts

 

[RobertTX]

Thanks, hot. I have been working on this one three days and getting discouraged. I'll keep at it.
I have bought many parts from him and been very happy with all. A search of his site for this tool comes up negative but as many parts as he moves maybe he has an extra I can buy or borrow.

 

[Woodslasher]

Soak it with penetrating oil then take a mini torch and heat it up, that will help the oil wick in. Also, get it nice and hot and melt a crayon against the crank, a neighbor uses that for stuck bolts and swears by it.

 

[RobertTX]

OK, by mini torch you mean propane? I have a shop full of tools and am afraid of getting too hot and damaging electronics. I appreciate y'all's experience, I have learned by failure in the past.

 

[cbfarmall]

I have only ever used a harmonic balance puller to remove these flywheels. Is the saw locked up? I tighten up the puller good and snug (use good allen screws for pulling and run them in full length without damaging the coil underneath) and whack the end as many times as needed.

I don't ever recall using heat to pull flywheels (concerns about the ignition and seals.) Also, in my opinion, penetrating oil will be useless on a properly tightened flywheel taper--how is it supposed to seep in there? Shock is what jars things loose. Leave the nut screwed onto the crank loose, pick the whole mess up by the puller and hit it.

 

[Brushwacker]

I don't remember for sure, but was thinking the flywheel key was sucectable to rust. I think penetrating oil likely would help and not hurt ease of removal.
If your flywheel is dragging on the coil, I would think a good possibility the bearing has play or is out letting the flywheel drag on the coil. If u haven't I'd take the coil off, soak shaft over night and try again . If you have a helper either pry up on the flywheel with 2 fair size screwdrivers or hold the saw up by the fly wheel while giving stout taps on the crankshaft with a nut a tiny bit over flush on the threads.
.

 

[Jasonrkba]

I believe the coil is behind the flywheel on that one. I could be wrong.

 

[hotshot]

Yup, and you can’t pry up on that 045/056 series’ flywheels…

 

[RobertTX]

Yep, everything is under the flywheel with no way to access the bottom or back of flywheel. I have beat and mushroomed the puller stem a bit.
Good thought on the key rusting, I have seen that on tractor hubs.
I am still a little spooky on heat but may get a bit more aggressive when I get back to this one.
Thanks for everyone's ideas. I am always open to help.

 

[RobertTX]

Finally got it! Couple weeks soaking with PB, mildly heated with propane once. Clamped clutch nut in vise and torqued on puller as much as I dared. Two blows with hammer and it was mine. Thanks for everyone's advice.

 

[hotshot]

Good to hear, patience paid off!

 

[SteveSr]

Soak it with penetrating oil then take a mini torch and heat it up, that will help the oil wick in. Also, get it nice and hot and melt a crayon against the crank, a neighbor uses that for stuck bolts and swears by it.

If this flywheel has magnets in it on the inside I wouldn't use heat. Enough heat will weaken/destroy the magetism. It may also degrade/melt the adhesive that holds the magnets to the inside of the FW.

 

[RobertTX]

Certainly over heating can do more damage than good. In this application my definition of heat is hotter than I want to touch but not quite enough to boil spit. Just enough to get a differential across the hub shaft interface. It did seem to help.