Chainsaw Repair

They are REALLY easy to miss! They basically are hidden in the chamfer on the ID of the inner race of the clutch side bearing. If you do not know the o-ring is there; have a dental pick to get them out, they are usually destroyed when you push the crank through the bearing during disassembly.

Given the 2$ price it is stupid not to continue to use them. I have worked with HVA products for over 45 years and have never seen the factory put anything into the design of their products that did not; make it work better; last longer or in the long run cost less!

If anyone is interested this is how the thing actually works:

1) the O-Ring part# 503 26 30-19 goes over the clutch side half shaft and rests up against the inner race of the clutch side bearing. Prior to the seal being installed
2) The seal part# 503 26 03-01 is then installed
3) Then the pump drive bushing part# 503 77 91-01 large side down so that it touches the o-ring
4) then the large flat washer part# 503 23 00-59 the object of the flat washer is to keep the pump drive from eating up the seal.
If your washer is stuck to the pump drive that is from heat it should not be that way.
Also the pump drive should not be a force fit on the bushing the pump drive should turn freely on the bushing. And the crankshaft should rotate inside the bushing without the bushing rotating.