044 PTO crank and oil spacer bush seal question

[MattG]

Nuts... I just put one together and installed the seal first, then the spacer bushing. Doesn't it make sense that the spacer can be removed from the seal area and reinstalled?

If it was me, I'd get another seal and start again. Sorry but that's just me. It's very poorly worded in the manual so I bet lots have ended up doing that. I guess if you just try to think of the bushing as "part of the shaft" a la @Brewz then it makes sense to do it this way.

 

[MattG]

I'm just really curious as to the drama involved with the O-ring at all. I mean first this pic in the w/s manual



and nothing in the IPL! WTF!


I'd not be surprised if the Oring was never ever part of any saws leaving the factory. Anyone stripped one and actually found one fresh from stihl?

Being in an engineering business myself, this just looks like a case of the engineers and the technical authors not really communicating too well with each other back in the day!

 

[BuckthornBonnie]

If it was me, I'd get another seal and start again. Sorry but that's just me. It's very poorly worded in the manual so I bet lots have ended up doing that. I guess if you just try to think of the bushing as "part of the shaft" a la @Brewz then it makes sense to do it this way.

Yah... There are ancient AS threads that claim the seal should go in first, then the bushing packed with grease. I went with that plus thinking Stihl wouldn't design an oiler system that necessitated seal removal to deal with.
I may take the clutch off and post pics.

 

[BuckthornBonnie]

I'm just really curious as to the drama involved with the O-ring at all. I mean first this pic in the w/s manual

View attachment 76076

and nothing in the IPL! WTF!


I'd not be surprised if the Oring was never ever part of any saws leaving the factory. Anyone stripped one and actually found one fresh from stihl?

Being in an engineering business myself, this just looks like a case of the engineers and the technical authors not really communicating too well with each other back in the day!

The general consensus and my observations is this--- that o-ring wasnt needed to keep any leaks below spec. Instead, the force of a torqued clutch and the makeup of the seal keeps things tight enough. I don't care for the design myself, but it must work.

 

[MattG]

Well I'm gonna go with @Canadian farm boy 's way for reassembly. I guess one could apply a smidge of sealant to the inner surface of that silly bushing and mega lube the seal's inner lips one were to be paranoid. But clearly as you state it does work - for many others.

I don't care for the design myself

Me neither and I think the guy who signed off on the original Stihl w/s manual should be shot.

 

[maulhead]

I'm just really curious as to the drama involved with the O-ring at all. I mean first this pic in the w/s manual

View attachment 76076

and nothing in the IPL! WTF!


I'd not be surprised if the Oring was never ever part of any saws leaving the factory. Anyone stripped one and actually found one fresh from stihl?

Being in an engineering business myself, this just looks like a case of the engineers and the technical authors not really communicating too well with each other back in the day!

Yes, a few of my early 10mm 044's I've taken apart have had the o-ring.

 

[MattG]

Yes, a few of my early 10mm 044's I've taken apart have had the o-ring.

Fair enough, thanks. I guess eventually they melted up?

 

[MattG]

@BuckthornBonnie
Sorry to go on about things but this whole area is a big bunch of ar$e. I just looked at the 440 w/s manual in the hope that the author of that wasn't on drugs......however the implication there is that the stupid f**king bushing can go on afterwards!


Logic still says to me, that it should go on before the seal. It would be nice to hear more opinions of more folks who rebuilt them! Perhaps I'm being a tad obsessive, but hey we are talking about the primary compression of a 2-stroke engine after all!

I'm not doing this job yet....but when I do I'll have a spare seal and do a lot of pressure/vac testing afterwards.

 

[BuckthornBonnie]

@BuckthornBonnie
Sorry to go on about things but this whole area is a big bunch of ar$e. I just looked at the 440 in the hope that the author of that wasn't on drugs......however the implication there is that the stupid f**king bushing can go on afterwards!
View attachment 76083

Logic still says to me, that it should go on before the seal. It would be nice to hear more opinions of more folks who rebuilt them! Perhaps I'm being a tad obsessive, but hey we are talking about the primary compression of a 2-stroke engine after all!

I'm not doing this job yet....but when I do I'll have a spare seal and do a lot of pressure/vac testing afterwards.

Haha, no worries. I bet either way would work but it just made more sense to install the seal first.

 

[BuckthornBonnie]

Fair enough, thanks. I guess eventually they melted up?

Yea, some would disintegrate. There's probably a tech note about it around somewhere.

 

[Brewz]

I always install the seal first.
No reason why, its just how I do it.
I bit of oil in the seal and gently push in the spacer.

Never had an issue

 

[Adamski]

@Matt

What ID is the o ring. I have a pack of them that fit my 372. They were slightly thicker than OEM and we're oil, fuel and chemical resistant. Couldn't quite work out from the thread if you had or were struggling to find one?

 

[MattG]

@Matt

What ID is the o ring. I have a pack of them that fit my 372. They were slightly thicker than OEM and we're oil, fuel and chemical resistant. Couldn't quite work out from the thread if you had or were struggling to find one?

Hi Adam,

I dunno whether to bother just yet, lots of folk reckoning that they aint needed. I'm a long way away from that stage in the proj TBH. I wanna see if the 12mm wrist pin crank will fit first.... etc. etc.
I'll PM you if I need the part.

Thanks dude!