372 XP Clutch Side Crank Seal

[K5krawler]

I am trying to get the o-ring to seal to the crankshaft and not leak. There has to be something I am missing as I have gone through 2 seals trying to fix this leak. I can barley pull 10 in/MG before I cant pull any more. The shaft leaks right away and I lose the vacuum. I am thinking the the o-ring I have is possibly out of spec causing the leak between the crankshaft and the o-ring. I think it is a HORRIBLE design and is a leak path regardless. I don't understand why Husky engineers didn't cast that shape into the original design.

Seal, O-ring as questioned.

The saw fails both pressure and vac test at the same location through the shaft and o-ring.

 

[SkippyKtm]

Are you sure that is the correct seal? The seal should ride on the large part of the stepped bushing, not directly on the crank to seal. It looks like the ID of your seal is to small to do that. I never have an issue with getting that seal to pass a vac test.

 

[K5krawler]

I should have said DISCLAIMER...that was the seal from the other side that I used to take the picture at the time. I do have the correct seals on the bench.

 

[Jacob J.]

Hmm, I've put about 80 365/371/372s together and never had a problem there.

As said above, you might have the wrong seal there. The bushing that the oil pump worm gear goes inside the seal.

 

[Jacob J.]

I should have said DISCLAIMER...that was the seal from the other side that I used to take the picture at the time. I do have the correct seals on the bench.

Ok, so you're using the correct seal. Are you installing too deep? Are you getting a good fit between the bushing and the seal?

Like I said, I've never had one of those leak and I've rebuilt a lot of those saws...

 

[K5krawler]

Ok, so you're using the correct seal. Are you installing too deep? Are you getting a good fit between the bushing and the seal?

Like I said, I've never had one of those leak and I've rebuilt a lot of those saws...

That's the only thing I can think is I installed it too deep. But the leak is not coming from the seal, it's actually coming from the area between the spacer for the plastic oiler and the crankshaft.

 

[Jacob J.]

That's the only thing I can think is I installed it too deep. But the leak is not coming from the seal, it's actually coming from the area between the spacer for the plastic oiler and the crankshaft.

Are you putting the bushing in dry or using some kind of grease/oil?

I use Valvoline full-synthetic grease. The seal should be flush with the edge of the pocket.

 

[Justsaws]

Between the crankshaft and steel bushing would point towards the $4.00 nearly invisible o-ring leaking between the crankshaft and bushing. O-rings have proved non re-useable and replaced by Dirko for me.

2 different size bearings, that would be a Stihl thing.

 

[tree monkey]

puy the clutch on to seat the o ring

 

[K5krawler]

Between the crankshaft and steel bushing would point towards the $4.00 nearly invisible o-ring leaking between the crankshaft and bushing. O-rings have proved non re-useable and replaced by Dirko for me.

2 different size bearings, that would be a Stihl thing.

Do you have a P/N?

 

[Justsaws]

Do you have a P/N?

o-ring=503263019

Dirko, is Stihl branded rtv gasket/seal maker, certainly does not need to be Stihl's Dirko. It does not take very much at all and using to much just makes a mess. I apply it to the bearing/shaft area with a small screwdriver(eye glass kit), let it set up and then install the bushing. Can put some on the bushing as well.

I am not opposed to the o-ring however everytime I have ordered one it has been one of those part plus shipping deals, and paying $4.00 for the 0-ring and $6.00 for the shipping per seal was not happening, did not improve when I tried getting 10 at a time.

There was a thread not long ago about the o-ring.

 

[Zippy]

I recently put one of these together.

The arrangement did look strange to me but worked well.

What worked for me:

Get it all clean
Tiny o-ring over the crankshaft and flush to the inner bearing race. Plenty of 2-stroke oil to lube it.
Install collar and oil seal.
Washer
Worm gear/oiler drive
Tighten clutch onto it

I did try a pressure test after putting the collar on just holding it down by hand and even that worked for me.

The o-ring is really small so easily damaged, but if repeated attempts fail then it suggests air coming between the inner bearing race and crank

More experienced people may be able to comment on that - I've heard of bearings being loose on cranks it but not experienced it.

 

[K5krawler]

Problem Found

I think I've found the problem from listing to you guys. The PO who had the saw prior to me tried to fix it and left the screws out of the oil pump (air leak) should have been a sign that the tiny oring was missing from the crankshaft when everything was disassembled. What I didn't know was there was supposed to be a tiny little oring there to seal off the shaft. Thus this is why I had a leak from the shaft to that spacer piece :bang::bang::bang:. If it had been there to begin with I might have not had this problem. That's the one thing that bothers me when people try to fix things and don't fix them correctly. This saw had the following broken (clutch, clutch cover, oil pump, oil pump drive, bad crankshaft seal, missing components...ugh dare I go on) not to mention the JB weld on the oil pump to try to fix the housing that was busted off.

I am going to try to source these. I know northwood saw has the seal (as I am on my 3rd one) but I doubt they have the Oring.

 

[Justsaws]

I have been told more than once that they are "not needed" by more than one repair shop. It was one of those little parts that sourcing the part was so frustrating that I just use a work around. Best of my knowledge there is no aftermarket or inexpensive non OEM replacement.

Good luck, be happy he did not put JB Weld in the bearings to quiet them down.

 

[K5krawler]

Parts

I have the parts on order and I am just waiting for them to come off of back order. I think they have been back ordered for 2 weeks thus far. It sucks waiting this long for a tiny o-ring but the PO has many other saws so it's not like it's a rush. Otherwise I'd be using one of the previous methods mentioned earlier to seal off the crank.

-K5krawler

 

[Roanoker494]

One of my local Husqvarna dealers can get me those o-rings for $1 each and there is no shipping charges because he just throws my order in with the parts order for the shop. If I order by Monday the parts will be here on Wednesday.

 

[eriklane]

I'm having the same issue. I have a air leak around the crank...So with the clutch and oil pump and bushing and O ring off, what are the steps to assemble those parts? I cannot visualize inner races and surfaces. Just say it in English what goes where and in what order. Can't be that hard. Does the tiny O ring go in BEFORE you insert the big seal?

 

[log_jammer]

Erik Lane, first is the o-ring. Then crank seal, oil inside of bushing and maybe just a little on outside of bushing. Insert bushing into seal. Next comes the thin thrust washer. Then the oiler gear and the clutch. As also previously mentioned, you can substitute a small amount of Dirko for the pathetic little o-ring. Best of luck.

 

[mdavlee]

Around the bushing or the crank? I've started replacing the bushings on high hour saws. A new seal won't seal tight enough to hold vacuum on some of the old ones

 

[Mattyo]

I'm having the same issue. I have a air leak around the crank...So with the clutch and oil pump and bushing and O ring off, what are the steps to assemble those parts? I cannot visualize inner races and surfaces. Just say it in English what goes where and in what order. Can't be that hard. Does the tiny O ring go in BEFORE you insert the big seal?

this should help