Flywheel removal made easy

[Jacob J.]

Some flywheels don't have the threaded holes for a puller, i.e. Rancher 51/55.

 

[jockeydeuce]

Some flywheels don't have the threaded holes for a puller, i.e. Rancher 51/55.

The old 380, 480 Husqvarnas are a pain to pull as well....Not much to hook a puller to......I've pulled a lot of 288 flywheels that I doubt you would get to pop without breaking them...They pulled extremely hard even with the proper puller.

 

[RBurtcher]

I would avoid whacking the crank on anything with needle bearings and thrust washers of any sort supporting the crankshaft.

 

[eiklj]

If I'm really pi$$ed off, I either drop kick the saw across the shop, or use a baseball bat. Either way, parts usually come off.
An M80 or cherry bomb stuffed in under the flywheel works too.

 

[Tzed250]

You can do that on most short fat-taper flywheels, but if there is a threaded insert for flywheel removal it probably has a long taper so use/make the correct tool.

Chainsaws aren't mowers; they idle faster than most mowers run. I would never put a vice grip on a fin. If you crack it and it comes off at 14,000 rpm, duck fast.

I've done it almost that way, except I hold the saw up by the flywheel with my hand, set a brass slug on the end of the nut and whack that with the hammer.

I just hold the flywheel by hand, supporting the weight of the saw. That way you're not going to crack/break fins and you work on your bicep strength at the same time...

Welcome back Andy!

If I have the correct puller, I use it. If not, then I remove the nut, flip it over, then thread it to within a half turn of flush. I hold the powerhead up off of the bench by the flywheel in my left hand and strike the nut with a brass hammer in my right hand. I figure since I can use this method with my SP125 it will work with most any saw. My doodads aren't big enough to put Vise-grips on a flywheel fin.

 

[heimannm]

The big McCulloch saw all have a couple of threaded holes in the flywheel. I made a large, thick washer with a couple of holes and attach it to the flywheel with a pair of 1/4-20 socket head cap screws and hook the puller to that. Even so, it is frequently necessary to give the puller a sharp whack witih a hammer to knock it loose, but I make sure I am supporting the saw by the puller when I whack it as I don't want to put any more load or impact on the bearing than necessary.

On most 10 Series saws you can still use a gear puller and get a good grip on the flywheel. Again a whack may be necessary to get it off.

Always leave the nut in place, prevents any chance of damaging the end of the shaft, and more importantly prevents the flywheel from becoming a UFO (Unexpected Flying Object) if it should happen to pop off when you are not ready for it.

Mark

 

[heimannm]

You can do that on most short fat-taper flywheels, but if there is a threaded insert for flywheel removal it probably has a long taper so use/make the correct tool.

Chainsaws aren't mowers; they idle faster than most mowers run. I would never put a vice grip on a fin. If you crack it and it comes off at 14,000 rpm, duck fast.

Nice to hear from you again Andy, hope you can join us from time to time and continue to share from your experiences.

Mark

 

[Dan_IN_MN]

If I have the correct puller, I use it. If not, then I remove the nut, flip it over, then thread it to within a half turn of flush. I hold the powerhead up off of the bench by the flywheel in my left hand and strike the nut with a brass hammer in my right hand. I figure since I can use this method with my SP125 it will work with most any saw. My doodads aren't big enough to put Vise-grips on a flywheel fin.

What is your reasoning in flipping the nut over?

 

[Tzed250]

What is your reasoning in flipping the nut over?

99% of the time the flywheel nut is a flange nut. Striking the flange side spreads the load over a larger area.

 

[Lakeside53]

Actually, the load area is the same - the threads. The striking area is bigger...but I'm being picky:msp_wink:

I should have added, use the right tool not only for "threaded insert" types, but for those that have any type of mechanical connection for pulling - like two of three tapped holes.

For the fat taper type, I also hold (by hand) the saw by the flywheel, but have a threaded sleeve on the crank thread rather than use the nut. It gets you some decent striking distance away from the fly wheel. For an end user that doesn't do it more than once in a blue moon, the nut works fine.

You don't need a machine shop to make a crank-end striker - just a piece of mild steel (hex is nice, but whatever) number drill and a metric tap. Make tools as you need them and soon enough you have a lot of resources.


I've seen a few broken flywheels and sheared cranks; sure makes a mess of the saw. On the aluminum centered flywheel (most short taper types) it's really important to use a torque wrench for reassembly. Overtighten and you can crack the flywheel center and it will most certainly come off at some point. MS200 types are real easy to break if you use an impact wrench. Don't ask how I know.

 

[tomdcoker]

Actually, the load area is the same - the threads. The striking area is bigger...but I'm being picky:msp_wink:

I should have added, use the right tool not only for "threaded insert" types, but for those that have any type of mechanical connection for pulling - like two of three tapped holes.

For the fat taper type, I also hold (by hand) the saw by the flywheel, but have a threaded sleeve on the crank thread rather than use the nut. It gets you some decent striking distance away from the fly wheel. For an end user that doesn't do it more than once in a blue moon, the nut works fine.

You don't need a machine shop to make a crank-end striker - just a piece of mild steel (hex is nice, but whatever) number drill and a metric tap. Make tools as you need them and soon enough you have a lot of resources.


I've seen a few broken flywheels and sheared cranks; sure makes a mess of the saw. On the aluminum centered flywheel (most short taper types) it's really important to use a torque wrench for reassembly. Overtighten and you can crack the flywheel center and it will most certainly come off at some point. MS200 types are real easy to break if you use an impact wrench. Don't ask how I know.

Glad to see you back Andy. I have learned a lot from your posts over the years. I hope you are back to stay. Tom

 

[Lakeside53]

I'll pop back in now and then... plenty of active and experienced posters here already!

My interests have drifted a bit. I now have a full ("hobby") machine shop - keeps me real busy.

 

[brncreeper]

I'll pop back in now and then... plenty of active and experienced posters here already!

My interests have drifted a bit. I now have a full ("hobby") machine shop - keeps me real busy.

Good to see ya back Andy.

 

[Tzed250]

Actually, the load area is the same - the threads. The striking area is bigger...but I'm being picky:msp_wink:

I should have added, use the right tool not only for "threaded insert" types, but for those that have any type of mechanical connection for pulling - like two of three tapped holes.

For the fat taper type, I also hold (by hand) the saw by the flywheel, but have a threaded sleeve on the crank thread rather than use the nut. It gets you some decent striking distance away from the fly wheel. For an end user that doesn't do it more than once in a blue moon, the nut works fine.

You don't need a machine shop to make a crank-end striker - just a piece of mild steel (hex is nice, but whatever) number drill and a metric tap. Make tools as you need them and soon enough you have a lot of resources.


I've seen a few broken flywheels and sheared cranks; sure makes a mess of the saw. On the aluminum centered flywheel (most short taper types) it's really important to use a torque wrench for reassembly. Overtighten and you can crack the flywheel center and it will most certainly come off at some point. MS200 types are real easy to break if you use an impact wrench. Don't ask how I know.

I should have been more picky with my explanation. With the flange up you have a large target and a large area to absorb the impact. The threads will feel the same force either way. To illustrate my point. Strike the corner of a wood block with a hammer, then strike a flat side. Which deforms more?

 

[Arrowhead]

I've used the hammer method hundreds of times. Never had a problem. Only I use a large blunt screwdriver to but a little pressure between the case and flywheel. Only one saw I had to use a puller on.

 

[Mad Professor]

I'll pop back in now and then... plenty of active and experienced posters here already!

My interests have drifted a bit. I now have a full ("hobby") machine shop - keeps me real busy.

Good to hear from you Andy.

Hope some of your "hobby" projects are saw applications you can share with us dirt floor mechanics

 

[tomdcoker]

I'll pop back in now and then... plenty of active and experienced posters here already!

My interests have drifted a bit. I now have a full ("hobby") machine shop - keeps me real busy.

I had a small machine shop at one time. I had three lathes and a 12x 24 three axis powered surface grinder. I specialized in sharpening blades for the box industry.
They started using throw away blades that were surfaced hardened on the cutting edge and when that was worn off it was throw away time. It put my shop out of business, but I was ready for it. Tom

 

[Lakeside53]

Sadly, over the past few years a large number of big and small machine shops closed and auctioned off around here. Seems to be slowing down, but....

Big capital invested, but in the end all you are selling is unit labor. A million or so in loans for the best cnc and you can get your unit costs down and make a little more, untll the next guys does the same and you are both competing for the same pie, and then there's China. Tough business.

Among other machines I have a nice 3 axis CNC BP mill with a conversational interface. Still... it's not a VMC, but I'm not going there yet. Damn "hobbies".

 

[Lakeside53]

Good to hear from you Andy.

Hope some of your "hobby" projects are saw applications you can share with us dirt floor mechanics

Not really. As many of you know I could care less about hot saws, or even wood's ports. A good sharp chain is like doubling your hp Muffers - ok, I do that. Oh, I have been known to chase (mig) about 30 feet of cracks in a mower deck, or make a new shattered chipper bearing mount, or... I'm a sad reminder of "just because you can doesn't mean you should". :msp_sad:

 

[Somesawguy]

Not really. As many of you know I could care less about hot saws, or even wood's ports. A good sharp chain is like doubling your hp Muffers - ok, I do that. Oh, I have been known to chase (mig) about 30 feet of cracks in a mower deck, or make a new shattered chipper bearing mount, or... I'm a sad reminder of "just because you can doesn't mean you should". :msp_sad:

Waste not, want not. I've done that with mower decks. I couldn't kill the old 3.5hp Briggs, but the deck was falling apart around it.