576xp sealed crankshaft bearing in 372xp case??

[Yotaismygame]

The bearing on the left is out of a 372xp and the bearing on the right is from a 576xp. Both are the same size. The 576 bearing has the crankseal built into it. The clutch and oiler setup is basically identical on both saws. I don’t see any reason why I couldn’t put a 576 bearing in a 372 case. Or maybe the sealed bearings could go on both sides and ditch the crankseals all together?

 

[Huntaholic]

Hmmmm.......... Ive built several of both of those saws and I never even thought of trying that! Im really hoping someone with more knowledge than me comes along shortly to tell us if this will work and why if it wont! In fact I wish you had made this thread yesterday because I just built a 575 today and the only part I don't have is the flywheel side seal but IF this will work I could have put a sealed bearing on that side too and deleted the need for a seal!

 

[Yotaismygame]

I just built a 372, and then did a 576 and now im on another 372 and after getting into another 372 I really think It would work. Im not sure on both sides but at least on the clutch side. If the bearing is sealed, and its the same size I dont see why it couldnt work for both sides.

Also the 576 has crank shaft stuffers, I'm wondering if they would fit the 372 crank. I didnt have both cranks on my bench at the same time but they also look the same.

 

[Deleted member 117362]

I just built a 372, and then did a 576 and now im on another 372 and after getting into another 372 I really think It would work. Im not sure on both sides but at least on the clutch side. If the bearing is sealed, and its the same size I dont see why it couldnt work for both sides.

Also the 576 has crank shaft stuffers, I'm wondering if they would fit the 372 crank. I didnt have both cranks on my bench at the same time but they also look the same.

 

[Huntaholic]

LOL I had those stuffers off today too and never even thought of seeing if they would fit a 372 crank and I even had a new 372 crank in my hands today too! I was rummaging through my extra parts boxes hoping to run across the seal I needed to put this saw back to work in the morning but didn't have any luck finding one. The next time I have a 372 tore down I will see about the stuffers. Iwill have to tear down another 576 though to get to a set. I think Ive got one stashed away somewhere with crushed crankcases but a good top and bottom end.

 

[Deleted member 117362]

If I understand you correctly, those bearing covers are not air tight. 372 uses 6202-c3 bearings and 576 has a proprietary clutch side bearing. Crank seals on cases are need to seal case and crankshaft on flywheel side. Seal on clutch side seals oil pump bushing and o-ring seals crank to bushing. If you vacuum check your case without those seals and o-ring, you will have major air leak and a short lived saw rebuild.

 

[Yotaismygame]

Let me know if they fit! Also if you need a 576 case I’ve got a couple. I needed one and the best deal I could find was for three used sets. Guy wouldn’t sell me one set only.

Sorry if there’s duplicates or weird stuff going on. The site seems to be having issues

 

[Yotaismygame]

Duce, the 576 does not have an o-ring or a separate crank seal. The seal is literally built into the bearing. I just put together a 576 by the book and it sealed up just fine

 

[Huntaholic]

If I understand you correctly, those bearing covers are not air tight. 372 uses 6202-c3 bearings and 576 has a proprietary clutch side bearing. Crank seals on cases are need to seal case and crankshaft on flywheel side. Seal on clutch side seals oil pump bushing and o-ring seals crank to bushing. If you vacuum check your case without those seals and o-ring, you will have major air leak and a short lived saw rebuild.

If I understand you correctly, those bearing covers are not air tight. 372 uses 6202-c3 bearings and 576 has a proprietary clutch side bearing. Crank seals on cases are need to seal case and crankshaft on flywheel side. Seal on clutch side seals oil pump bushing and o-ring seals crank to bushing. If you vacuum check your case without those seals and o-ring, you will have major air leak and a short lived saw rebuild.

What hes talking about is using the proprietary 576 clutch side bearing in a 372. The 372 has a bearing, a tiny O ring, a seal, a sleeve that oil pump gear rides on and lastly, a seal. The 576 bearing has the seal built into it. After thinking about it some more it seems that you would still need the seal in the 372 for the sleeve that centers the oil pump worm gear so it might just be double sealing that side which I don't think would be a bad thing. The biggest drawback I see is the cost of the $30 bearing VS the cost of the standard bearing. Input?

 

[Huntaholic]

Duce, the 576 does not have an o-ring or a separate crank seal. The seal is literally built into the bearing. I just put together a 576 by the book and it sealed up just fine
View attachment 695307

576 has a regular seal on the flywheel side and no o ring or seal on the clutch side. Its a sealed bearing on that side

 

[Deleted member 117362]

Sorry, thought you are rebuilding a 372. If I got that right, what you are saying will not work.

 

[Yotaismygame]

The idea is to put a 576 bearing in a 372 and ditch the seals. The 576 has the sealed bearing, sleeve with washer, then the oiler stuff and clutch. The 372 is almost the same except the sleeve needs sealed to the case and sealed to the crank shaft since the bearing is not sealed itself. The way I see it is if the bearing is sealed then the crankcase is sealed. The sleeve wouldn't need an O-ring or the crankcase seal.

Huntaholic is right though, the cost of that bearing is twice as much and theres really no reason to do it that way unless you dont wont to bother with seals and o-ring

 

[Chainsaw Jim]

Once you get the 576 bearing in the 372 case you'll no longer be able to change the seal unless you split the case and punch the bearing back out.

That and you'd be replacing a $5 bearing with a $35 one.

 

[Yotaismygame]

But you’re saying it would work?

 

[huskihl]

I'm with Jim. It might work, but your proprietary bearings are gonna cost $70, vs $20 for Nachi's and seals. And you can't replace them without splitting it.
I guess it won't matter on an xt as the seals outlast the bearings anyway

 

[Yotaismygame]

Exactly what I wanted to hear. Any idea if the 576 seals in the bearings last longer? But yeah I picked up three 372s and all of them had blown clutch side bearings

 

[huskihl]

Exactly what I wanted to hear. Any idea if the 576 seals in the bearings last longer? But yeah I picked up three 372s and all of them had blown clutch side bearings

It's not that the seals last longer. It's the heavier xtorq piston combined with a 50:1 oil ratio that wears out the plastic bearing retainers in a few years time.

 

[cuinrearview]

I'm with Jim. It'll work, but your proprietary bearings are gonna cost $70, vs $20 for Nachi's and seals. And you can't replace them without splitting it.
I guess it won't matter on an xt as the seals outlast the bearings anyway

In layman's terms, you'd be stepping on your own ****, or bringing a Stihl problem to a simple Husky

 

[huskihl]

In layman's terms, you'd be stepping on your own ****, or bringing a Stihl problem to a simple Husky

Some huskies have it too. 390, 346,...among others have a proprietary bearing or seal on the clutch side. Such a pain

 

[cuinrearview]

Some huskies have it too. 390, 346,...among others have a proprietary bearing or seal on the clutch side. Such a pain

At least prices have gotten a little better.