What would make this seal tear? (036)

[BuckthornBonnie]

Leaving us with the crank--- you can see the step Al mentioned. If it's clean, it probably couldn't do anything.

 

[BuckthornBonnie]

I suppose the seal could have popped out into the path of the washer, but that crank step is a positive stop. Wrong washer? Clutch drum retainer used instead? Again, probably not.
I think it's a fluke as mentioned above. Cool failure and nice to have video evidence--- reinforces the importance of listening to saws when you're cutting. "The tune don't lie" to paraphrase Rasheed Wallace.

 

[Chainsaw Jim]

Do you use loctite on the outer edge?

 

[drf256]

I suppose the seal could have popped out into the path of the washer, but that crank step is a positive stop. Wrong washer? Clutch drum retainer used instead? Again, probably not.
I think it's a fluke as mentioned above. Cool failure and nice to have video evidence--- reinforces the importance of listening to saws when you're cutting. "The tune don't lie" to paraphrase Rasheed Wallace.

Thanks for all the pics. Very infomative.

It's possible the seal was put in slightly cockeyed. Not sure if that would do it.

I used a socket and not an oem tool.

It was symmetrically placed. It's possible I dented the edge in a bit.

I really have no idea, but like it was mentioned above, I'm glad it went out before I sent the saw out. Pretty happy I made as many cuts as I did. I knew it was all brand new and wanted to be sure it would hold up. The piston survived just fine. It takes a lot more cutting than one would think to score a piston.

 

[drf256]

Do you use loctite on the outer edge?

Not sure what you mean Jimmy?

 

[angelo c]

Not sure what you mean Jimmy?

lube the lips and seal the seal..I use yamabond-very lightly. oddly enough I don't recall seeing any sealant when removing OEM seals that were factory installed.

 

[Duane(Pa)]

Not sure what you mean Jimmy?

Where the outer circumference meets the case.

 

[Mastermind]

I rarely use any type of sealant. Once in a while I will on a mag case that is a little corroded.

 

[BuckthornBonnie]

I rarely use any type of sealant. Once in a while I will on a mag case that is a little corroded.

I haven't seen a factory seal with anything but I always put a tiny amount of 518 on the edges. My logic (probably flawed): install and then removal of the original seal could have removed just enough material to leak a bit. The sealant should seal that. 518 is better imo because of it's ability to flush out and only anaerobically cure.
Probably overkill and not needed, tho.

 

[BuckthornBonnie]

Where the outer circumference meets the case.

Lakeside? or another venerable AS poster once claimed some seals could leak a tiny bit and then not. I think someone even referenced oil/grease/dust buildup as how the tiny leak stops. Sealant seems like good insurance but who knows.

 

[Al Smith]

I've only had one that blew the seal .It was an 038 Mag I had rebuilt three times that had served over twenty years in hard service as a tree service saw .That one I used red loctite .BTW I own that saw now and it probably runs as good today as it did in the 80's when it was new .Tough old saw.

 

[drf256]

Saw 100% now with new oem seal installed the same way.

Must have been a bad seal.