MC 101b/SP 125 C replacement drum bearing.

[burl1984]

I did a ton of searching for a new clutch drum bearing for the saw that I'm building. After hours of searching threads I came up with this idea not sure if someone has already posted this somewhere but i couldn't find it so here it is.
HVP 503 13 29 01.

Basically I toasted the bearing on the clutch hub because the crank that I was sold was a right hand thread crank p/n 69346. All my other saws have had a left hand crank thread feature and I wasnt aware that there was a left hand thread 101b crank option at the time that I first put the crank in the engine I found. Needless to say on the first start up I spun off the clutch at a rather high rpm. The chain did however remain in the 9 pin rim drive but it was riding on the bearing itself and basically ruined it. I have recently replaced the crank with a p/n 90872 "left hand thread 101b crank".

I couldn't find a listing that showed direct application replacements from oregon for the SP 125 C drum bearings so I searched for 9/16" chainsaw drum bearings and a 2100/3120 husqvarna came up on the google list. I just happen to have 1989 vintage 3120 that is in good running condition so I took the clutch drum bearing out of the 3120 and slid it nicely onto the 101b crankshaft and put the SP 125 C drum over it. It fits nicely!

HVP is 19.00 from baileys. This may be a cheaper option http://www.baileysonline.com/Chains...Bearings/Drive-Sprocket-Bearing-ORF 21276.axd
It's the oregon brand of bearing for the 3120 but only costs 8.00.

IMO the OEM HVP is much higher quality and resembles the OEM McCulloch 125 p/n more so than does the Oregon bearing.

I hope this helps anyone in need of a replacement McCulloch drum bearing that hasn't been able to source an OEM one.

 

[Jacob J.]

The Husqvarna 394/395 sprocket bearing fits the Mac 125. Those retail new for $7.95 at Husqvarna dealers, unless the dealer is a crook.

 

[burl1984]

The Husqvarna 394/395 sprocket bearing fits the Mac 125. Those retail new for $7.95 at Husqvarna dealers, unless the dealer is a crook.

I must have tried the wrong bearing from my brothers 394. He has his 394 in the process of converting it to the 395 and I must have tried fitting the old connecting rod bearing instead of the drum bearing. I'll check again tomorrow to see about the 394/395 drum bearing as well. Thanks for the input!

 

[Jacob J.]

I must have tried the wrong bearing from my brothers 394. He has his 394 in the process of converting it to the 395 and I must have tried fitting the old connecting rod bearing instead of the drum bearing. I'll check again tomorrow to see about the 394/395 drum bearing as well. Thanks for the input!

The 394/395 uses the same drum as the 2100, 2101, 281, 288, 181. The only real difference in the 3120 drum is that is doesn't have the drive tangs for the 394/395 oil pump worm gear because the 3120 uses a different style of worm gear. The sprocket bearing is the same. This is an old trick that's been around for years.

One that most people don't know about though is that you can use the clutch drum off a Mac 10-10 on a Husky 365/371/372 if you cut the slots on the side for the oil pump worm gear.