Removing clutch hub from 066

[Skooks]

OK, maybe I am missing something obvious here but does anyone have any tips for unscrewing the clutch hub on an 066?

It's screwed on pretty tight. I tried the old rope-in-the-cylinder trick but the hub wouldn't budge. I didn't want to wail on the wrench too hard for fear of breaking something.

Is it left-hand thread (seems like it must be).

-Thanks!

 

[lucky]

Its probably left hand thread and you should be able to use an impact wrench on the forward setting to remove the clutch. to install, spin on by hand then tighten with impact. it helps to use a 3/8 impact gun or just be careful to not get it so tight that it breaks. take it easy. Lucky

 

[stihltech]

impact

Many of the consumer saws (Stihl and others), use a flywheel with a cast in key. An impact wrench may(Will)break this key.
Use the rope or a piston stop. I have to use a pipe on a 3/8 ratchet sometimes.
Your 66 does not have this key, and the impact will work ok, but the warning needs to be mentioned for others.
I have went away from the impact due to this.

 

[Skooks]

Thanks for the information everyone! I will let you know how it goes.


-Don

 

[Dennis]

I have found that the impact is great for taking the clutches off, but do not recomend using them to tighten them back on. The "star" in the center of the clutch can break very easily when an impact is used to tighten..I have found this many times.

 

[Skooks]

Left-hand thread?

The clutch hub does use a left-hand thread doesn't it?

 

[JimL]

Originally posted by Dennis
I have found that the impact is great for taking the clutches off, but do not recomend using them to tighten them back on. The "star" in the center of the clutch can break very easily when an impact is used to tighten..I have found this many times.

I put most of them back on with a 3/8 impact, not much knocking, just spin them good and pull the socket off, it tightens up when it stops. never had one come loose...


Use my 1/4" impact on outher screws

 

[NevadaWalrus]

I use the impact whenever possible and as of yet haven't had a problem with breakage, not with Stihl anyway, nor with one piece flywheel keys shearing. Perhaps I've been lucky but restraint in air gun setting and throttle triggerering play into it.

Any breakage in tightening would be pretty lame because like Rocky said you don't really need to make it all that tight. I just snug it up with a feathered trigger pull.

And I'm probably lucky in the fact that since the vast majority of what our shop sells is Stihl most of my repair work is on a good product to begin with.

 

[Crofter]

Re impacts and needle bearings

It is probably a very small risk but I have read that since needle and ball bearings have only point contact with races that impact wrenches can cause micro chipping of elements that lead to early bearing failure. Just food for thought.

Frank

 

[NevadaWalrus]

Something to think about. Every time that combustion chamber fires its doing exactly the same thing to parts as an air gun except for possible clutch spider damage. If you're gonna use a 400 ft lb 1/2 gun, that is not using restraint.

Use reasonable setting on air pressure and trigger pull, what the engine does every time it fires is the same to bearings or the flywheel as the impact gun.

 

[Crofter]

Nevada; I think the power pulses are a lot gentler. Unless you are into detonation the burning is supposed to be progressive and the needles and balls are then in motion when receiving the loading rather than stationary when being hit by the impact wrench. But really I am quibbling over a pretty obscure risk in the big picture. Glens hasn't been posting in a long time and I am trying to keep the tradition alive. Lol.

Frank