Stihl 041 AV Sprocket Question

[jmr302]

Hi all. I'm new here. Found this site on Yahoo and couldn't be happier. You all have a good thing going here.

I'm helping my inlaws with equipment maintenance at their new tree nursery in Newton, KS. The oldest saw in the fleet is a Stihl 041 AV. It's old enough that it doesn't have the kick-back chain brake or whatever that's called. Appears to be all-metal as well. Anyway, the drive sprocket is worn out and I'm trying to replace it. The trouble is we don't have service manual for this saw. My dad-in-law already got the left-threaded nut off. What I'm wondering is how the clutch comes off. Is it pressed onto the shaft? Is the 3-fingered center piece left-threaded onto the shaft?

I took a picture so everyone could see what I'm talking about. Click on this link to view it.

I have an automotive repair background but I don't know much about chainsaws yet. The rest of our saws are late model commercial Huskys but we want to keep this old Stihl running.

Any help would be appreciated!!

 

[tree monkey]

left hand threaded,but 2 of your clutch shoes need shoes.

later

 

[njforestfire]

From the looks of the clutch....it appears to be pressed on (there is a slight recessed taper in the end of the shaft for the point of the puller to go). There should also be a 'key' between the clutch and shaft...don't lose it when taking apart. You might want to think about using a 2 or 3 jaw puller to remove before trying the 2 large screw driver method (last resort). Do all 3 shoes appear to be worn the same amount? The pic appears to have been taken on a slight angle so I can't tell about the shoe wear. Good luck.

John

 

[Ax-man]

It's threaded on the same as the nut. Sthil has a service tool that is somewhat similar to a spanner wrench ( for lack of a better word ) the service tool fits between the slots in the in the three shoes, with a handle to break break the clutch loose and spin it off.

Using the tool is the best way to remove a clutch like that, but I doubt you will find one, if you don't want to take it to a shop , which would be best, then your going to have to use the direct approach. I really hate saying this, but the clutch is going to need new parts anyway, jam the piston and use a long punch and ballpeen hammer and take it off the same way you did the nut. I really hate telling you to do it this way as clutches on those bigger saws can be tough, and you run the risk of damaging internal engine parts and the whole clutch just might end up junk. If your concerned about the saw take it to someone who has the proper tools.

I got my heat sheild on for this post.

Larry

 

[thompson1600]

Nice to see you back Tree Monkey, missed your posts.

Tom

 

[cbfarmall]

I don't think it a good idea to lock the piston and then bang away with a hammer. The cylinder compression has always been enough for me. Only problem I've ever run into is when the clutch didn't easily spin off after breaking loose. I had to keep tapping it around with the hammer and chisel. That tended to push the shoes off the hub. Once I got the clutch off, I cleaned up the threads with a diamond file (since you can't buy a left-handed metric die nut). Then, everything was copacetic.

However, like Ax-man said, the factory tool is best. I've found that the one I bought for my 045 works on all the other saws I've needed it for. Wasn't expensive: 6 or 7 bucks.

Chris B.

 

[Grande Dog]

Get yourself a cheapo hex socket. The flat sides of the hex have to fit over the rounded part on the center of the clutch hub, that determines the size of socket to use. As far as the drive size goes thats your choice. The best size would be whatever size air impact you have. That way you won't have to mess with a piston stop. On the hex side, from point to point of the hex, take a hacksaw and slice into the socket about a 1/2". You'll have to do this 3 times. Now remove every other ear and you'll have a clutch tool. Depending on the quality of the socket, it might actually last awhile.

Grande Dog
Master Mechanic
Discount Arborist Equipment and Tree Care Supplies

 

[jokers]

tree monkey, who happens to run a successful Stihl shop, is right.

Grande Dog gave you an excellent method for making your own wrench. Grande Dog is also very knowledgable(not that you other guys aren`t) and is our local rep for Bailey`s, who you might have noticed is a big sponsor here.

Just trying to give you a little background on who`s who, JMR302.

Welcome to the Chainsaw forum JMR302!

Russ

 

[Ax-man]

Grande Dog,

That is an excellent idea, I probaly will make one for myself, sometimes those handle clutch tools just don't have quite enough leverage to get the job done, and have to figure out a way to a little extra leverage.

Shows there is a big difference between doing it for a living as opposed to just having to maintain saws you own to earn a living.

Thanks

Larry

 

[jmr302]

Thanks for the replies. I made a tool like Grande Dog suggested out of a cheapo 13/16" spark plug socket that was laying around. I just dove in with an angle grinder and removed 3 of the 6 flats. It was fast and sloppy but worked well since the clutch is not torqued down very hard. Speaking of which, what is that torque value?

I can't believe I didn't notice that there was no friction material on two of the clutch shoes until somebody said something. I probably would have noticed when I removed them but it's still a little embarassing. :blush:

 

[bwalker]

I actually made a tool like this out of a cheap chinese made socket and it broke. Take out only the amount of material that is absolutly neccessary.

 

[Beavergirl]

S-

Consider a rim sprocket conversion assy from Oregon. Check your serial number for applicable article. I also opted for an 8 tooth sprocket to increase chain speed. This setup works very well for my old saw.

[original link to oregon sprocket chart inoperative. Process the selector guide at www.oregonchain.com]

C-