Stihl 041 drum differences? Need help please.

[dsell]

Can anyone please explain the differences on the Stihl 041 drums? Did some use a washer with a pin to drive the oil pump and some didn't? Why would some spurs be .500, .311, and .302? Also, did they vary the clutch from 5/8" to 1/2"?

1113 640 2000
The sprocket is .311 inch thick and the clutch area is .643 inch. Overall this drum is 1.10 inch tall, 2.864 OD, 2.714 ID, Stihl Spur Drum 3/8 Pitch 7 Tooth. Bearing bore is .589 inch. Made for 5/8 clutch.
041 before S/N 5664891

Herr 3/8-7 Clutch Drum 045-A7
Stihl 041, 041AV, 041AVE (Before No. 5664891)
2.703 inch drum I.D.
2.870 inch drum O.D.
.590 inch bore for bearing
.560 inch bore depth for bearing
1.116 inch overall width
.302 inch spur teeth width
.474 inch crankshaft diameter, this is what it measures, could be the wrong bearing.


Stihl 1110 007 1017 Spur
The sprocket is .311 inch thick and the clutch area is .643 inch. Overall this drum is 1.10 inch tall, 2.857 OD, 2.717 ID, Stihl Spur Drum Chainsaw Sprocket 404 Pitch 7 Tooth. Bearing bore is .588 inch. Made for 5/8 clutch.
041 before S/N 5664891


Oregon Chainsaw Spur Sprocket 3/8 Pitch 7 Tooth 3/8-7 32060 The sprocket is 1/2 inch thick on this drum verses 5/16 thick on the Windsor ST43A7. Also, this drum is a bit shallower than the Windsor like 1/2 inch clutch on the Oregon verses 5/8 clutch on the Windsor.
32060 for 030, 031, 032, 041 (after S/N 5664891) per the Oregon catalog.
Also fits Olympyk (Oleo-Mac) 251, 350 (before 1988), 252, 254, 355
Identical to Oregon 27954

 

[alexcagle]

I'm confused too, now.......lol

 

[dsell]

The IPL snip is from the 041 AV

 

[dsell]

Below is a link to a very descriptive article on changing the oil pump. He states that some have a spacer washer between the clutch and bearing and some don't.

https://forum.ih8mud.com/threads/st...1-farm-boss-041av-041-super-1968-1982.616687/

It appears to me the thick washer, (0000 961 1001), he refers to is used with the rim type drum. It's the same part number on the 041 FB and 041 AV.

The 041 FB and 041 AV IPL's both show the same clutch shoe 1113 162 0802 and call out the same drum 1113 640 2000.

I wouldn't think I need to look at the 041 G IPL, are there any other IPL's?

 

[William Balaska]

Well they all need the washer to turn the worm to run the pump.

 

[dsell]

Well they all need the washer to turn the worm to run the pump.

If you looked at the guys post on changing the oil pump, you can see washer #23 between the bearing and clutch. That seems strange because according to this, that's only for the rim type drum and his saw had a spur. He also stated #26 was on his saw. #23 just goes over the threads, not the bearing surface. Who knows, maybe someone took of the rim system on his saw and installed the spur, but left #23 on.

 

[William Balaska]

#18 the washer has a pin that drives the worm. Pretty sure I have both setups, I have four 041s and boxes of carcass.

 

[dsell]

#18 the washer has a pin that drives the worm. Pretty sure I have both setups, I have four 041s and boxes of carcass.

Was there an early version of the 041 that didn't drive the oiler with the pin? The Herr book shows 045-A7 for the early 041, and it doesn't have a pin hole. Is it possible the pin drive was larger diameter and the pin caught between the teeth of the spur?

 

[dsell]

Notice the discrepancy between the doc and drum, 183 vs 188. 183 does exist, and I can't find 188 in the catalog.

 

[William Balaska]

Unlikely. I have a first year gear drive and it has a worm gear and is driven by the sprocket.

 

[William Balaska]

here's an example of a spur and rim sprocket out of my hord.

 

[William Balaska]

If you looked at the guys post on changing the oil pump, you can see washer #23 between the bearing and clutch. That seems strange because according to this, that's only for the rim type drum and his saw had a spur. He also stated #26 was on his saw. #23 just goes over the threads, not the bearing surface. Who knows, maybe someone took of the rim system on his saw and installed the spur, but left #23 on.


View attachment 639973

23 is just a spacer. Probably accounts for the narrower width.

 

[dsell]

Here's a used 183-A7 and it looks like it's the thicker spur. According to the Herr book, that's after serial 5664891.

 

[john-ford-t]

Hello, guys, this is the info I know from years of repairing and running Stihl saws. The 045 clutch isn't compatible with the 041. The drum with the thin spur sprocket is used on 040's and "first generation" 041's (1968-1971) then the second generation 041's used the same clutch as the early saw, but the drum has the thick spur sprocket; and, uses the little spacer (#23 in the above IPL) also you have to be careful about the washers that fit on both sides of the clutch. They do have different offsets and thicknesses. All 040's and 041's use the washer with the hole in it and the pin through the hole drives the oil pump worm gear. As well as this the 031 uses the same clutch and the drum with the thick spur sprocket, and the drive pin for the oil pump; however the washer with the hole for the pin has a little raised ridge around the center, and that ridge fits into the bearing bore in the sprocket. because of that the needle bearing for the 031 is shorter. As well as all this the clutch cover on 040's and early 041's is shallower where it fits over the clutch drum; however if you have a "assembled" saw the Farm Boss clutch cover (post 1971) that wraps around the muffler will fit over all the clutch combinations without any interference problems. Sorry; though, I haven't ever worked on the 041G (gear drive) so I can't comment on that particular variation.
I sure hope this wasn't too wordy or confusing; and I hope it helps. Yours, always, John Schreiber.

 

[dsell]

The illustrated parts lists I have don't do a very good job of showing what you described, but what you said makes sense. Do you think they extended the drum out with the thicker spur and spacer washer for the chain brake or simply for chip clearance? I have two parts list, 07/2004 041 AV 1110 and 041 FB SCS 01-2011 3.33 I know there is a manual for the gear drive, but I'm not concerned with it. Do you know how many more parts lists there are for this series? On any Stihl product, how do I know I'm looking at the correct parts list?

 

[john-ford-t]

As I recall, Stihl revised parts lists as new/cheaper/better parts were developed. I remember continual revisions of the microfiche parts indexes ocurred on a regular basis.
The earliest parts lists were included in the owners handbooks as well, and even those could and did have supplemental revisions which were printed and added to the owners manual at the time of sale. Stihl service manuals (never released to the public) always referenced the serial # from which changes became official; however there was considerable overlapping of design changes. The thicker spur sprocket was developed for better chip clearance; and Stihl was continually planning " future" development of the design series, ie: the chain break. Most IPL's available now only show the later saws. As well; when the pressed together crankshaft came out; it was machined with a longer distance between the worm drive and the threads, that's why the spacer was needed (as well as the thicker spur sprocket ) I can only say that I will do everything I can to help you get the right parts for your saw. Yours; John Schreiber P.s the Ipl's fit saws between specific serial #s; usually Stihl would indicate " this parts list supersedes the previous list from serial#---------. for units prior to serial#-------- use the previous parts list" I do know that the illustrated parts are drawings of the actual parts, at least after 1971 or so. John.

 

[dsell]

Thanks John. Based off what you said and the after market catalogs I have, it appears the Herr 045-A7 is a mistake either on application or the fact that it doesn't have the oiler hole. It is the thin spur which correlates with what you stated on the early 041 and the drum dimensions are correct. My guess is the Herr factory missed putting in the oil hole pin on a batch.

 

[csquared123]

I hope you all still look at this thread. I have a 041av and the sprocket is constantly engaged. The clutch is good but when I tighten it, it presses against the back of the sprocket housing in so that the clutch and sprocket only spin together. The saw is unsafe to use (essentially) without a clutch. I think I need the #23 washer indicated above in order to create some space and have the clutch apply pressure/make contact with the crank shaft and not the sprocket housing. Anyone experience this? The saw runs great otherwise and I'd hate to throw it away over this.

 

[dsell]

That sounds reasonable to me.

 

[Patrick1903]

I hope you all still look at this thread. I have a 041av and the sprocket is constantly engaged. The clutch is good but when I tighten it, it presses against the back of the sprocket housing in so that the clutch and sprocket only spin together. The saw is unsafe to use (essentially) without a clutch. I think I need the #23 washer indicated above in order to create some space and have the clutch apply pressure/make contact with the crank shaft and not the sprocket housing. Anyone experience this? The saw runs great otherwise and I'd hate to throw it away over this.

Reviving another old thread since your scenario is also what I'm experiencing with my 041FB. I got this saw last year and have been trying to rebuild top end, so I don’t know if the current configuration of the clutch/sprocket has worked properly. My issue may be related to the clutch springs based on limited clearance with the drum. I need to replace springs first and test. I am not 100 sure if I have the correct configuration based on the ipl.
I have the rim sprocket setup. When I tried to run the saw last week, I pulled chain through by hand and it turned the motor over. After pulling clutch, I thought I was missing a curved washer between the clutch and clutch drum. I ordered that and installed it. No difference. Then I’m looking closer at clutch and drum and think I’m making contact there at one side of the clutch. So I’m going to try to replace the springs. I will try to outline the IPL again and what my configuration looks like in case someone can tell me if I’m reading the IPL wrong. I think my issue is when they have two configurations (ie rim or spur), at one point do you go back to the main drawing sequence to pick up those items. Not sure if that makes sense, I’ll try to draw with IPL.
I have all the items in red. So after #23, I thought I needed #26, so I bought that and added that between 23 and the clutch. I am not exactly sure I understand what keeps the clutch from pushing into the drum on the backside of the clutch after screwing it onto the crank. The washer, 26, would separate them now, but does the clutch just spin against that until the shoes engage the drum, thereby turning the drum?




and here’s my clutch…could be the problem to begin with.