372 XP Clutch Side Crank Seal

[Mattyo]

the inner race of the bearing is PRESSED onto the crank...there is no space between the two. the bushing snuggly fits the crank, but is not airtight. the o-ring effectively seals the bushing to the crank/bearing assembly. the main seal then acts as a seal between the case and the bushing.

so again, there are 3 interfaces that could be leaking... case/metal seal ... rubber seal / bushing and bushing/crank.

which one is it?

you do not do a pressure test with the bushing out.

 

[eriklane]

Crank seal replaced today, new O ring, no leak. BOOM!

 

[Mattyo]

nice

 

[fleethirte]

sorry to revive this thread… I am curious. Can we just use three bond to seal the bushing to the bearing and then for safe measure put some also on on crankshaft to seal inner part of bushing?

I am having leaking from this bushing as well and I have the tiny o ring from the video Mattyo made installed.

Just brainstorming …

 

[huskihl]

sorry to revive this thread… I am curious. Can we just use three bond to seal the bushing to the bearing and then for safe measure put some also on on crankshaft to seal inner part of bushing?

I am having leaking from this bushing as well and I have the tiny o ring from the video Mattyo made installed.

Just brainstorming …

I’ve never used the o ring. Most 372’s don’t even have one.

Smear some sealant around the crank and twist the bushing on and install oil pump bits and clutch

 

[fleethirte]

I’ve never used the o ring. Most 372’s don’t even have one.

Smear some sealant around the crank and twist the bushing on and install oil pump bits and clutch

I like it, does she pass pressure test?

 

[Woodslasher]

I've encountered a few 372's with no o ring when I took them apart, I put them back together with the original bushing, no o-ring, and no sealant (because I had no idea anything was supposed to be there) and I've yet to see them have issues. And as I recall they passed pressure/vacuum tests just fine.

 

[huskihl]

I like it, does she pass pressure test?

Definitely. Even without the clutch

 

[huskihl]

I've encountered a few 372's with no o ring when I took them apart, I put them back together with the original bushing, no o-ring, and no sealant (because I had no idea anything was supposed to be there) and I've yet to see them have issues. And as I recall they passed pressure/vacuum tests just fine.

Slow fixed leaks that aren’t on their way to becoming worse are fine. But either way, a little bit of grease or sealant inside that bushing seals it all right up so you don’t have any issues down the road

 

[RedneckChainsawRepair]

Most just do like Kevin above does with grease or the threebond etc.

But when doing folks saws here I always do the o-ring. Since the oring is even in aftermarket now and they are dirt cheap. Used to use oem till they came out.

I figure they came with it from OEM. That I'm not sending a saw back out without.

Have had folks bring in clone 372's in past acting wonky, that put the orings in for owners. Then no issues.
My G372xp pro even came with it in a clone.

 

[huskihl]

Most just do like Kevin above does with grease or the threebond etc.

But when doing folks saws here I always do the o-ring. Since the oring is even in aftermarket now and they are dirt cheap. Used to use oem till they came out.

I figure they came with it from OEM. That I'm not sending a saw back out without.

Have had folks bring in clone 372's in past acting wonky, that put the orings in for owners. Then no issues.
My G372xp pro even came with it in a clone.


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The very reason I don’t use them is because I have only seen that O-ring twice out of maybe 15 372 rebuilds. If the O-ring came out or disintegrated, it’s not doing any good. I always figured that sealant would remain on the crank long after that O-ring head disintegrated

 

[fleethirte]

What drives the oil pump gear?
Is it becuse it is sandwiched between the clutch and the crank sleeve?

 

[huskihl]

What drives the oil pump gear?
Is it becuse it is sandwiched between the clutch and the crank sleeve?

A worm gear just like every other

 

[fleethirte]

Lol
I should have been more specific, what spins the arm that is connected to the worm gear. I know the 660 catches a slot in the clutch cover…

 

[fleethirte]

Nevermind, I see the notch in the flywheel cover.

 

[huskihl]

Clutch drum

 

[fleethirte]

Clutch drum

Off topic question… do you secure the outside dog to the clutch cover? My 372 kit dosent have a hole there for a screw?

 

[singinwoodwackr]

Off topic question… do you secure the outside dog to the clutch cover? My 372 kit dosent have a hole there for a screw?

Drill/tap

 

[huskihl]

Off topic question… do you secure the outside dog to the clutch cover? My 372 kit dosent have a hole there for a screw?

Outer dog on a 372 mounts to the bar studs

 

[singinwoodwackr]

Outer dog on a 372 mounts to the bar studs

Mine has a tapped 4mm hole/screw which simply holds it in place when the cover is removed.