Loose/spun PTO side bearing on a 550 MKII

[LittleTree]

Hello everyone, i'm rebuilding this 550mk2 Who suffered from PTO side bearing failure, kinda evergreen on a 5 series. It Is mu First bottom end rebuild, and It was going all smooth until i found out that the inner race of the new bearing spins almost freely on the crankshaft. Still, i had to press fit It which makes almost nonsense. Maybe there's some wear on the crankshaft i Guess? Is there any way to get the fit to work properly? I feel like this could be a Major long term issue if i Just put the saw back together and maybe run It.

 

[Woodslasher]

Use some sleeve retainer maybe?

 

[LittleTree]

@Woodslasher i was thinking about It, i read of some people using loctite 628 or 620, but with It being on the full-time-stressed pto side i wonder if It Is gonna let go sooner o later.

 

[J D]

You will have a press fit until the bearing gets to the position it was spinning in... then it will be loose & leak. Can knurl or punch dimples around the crank so the bearing is an interference fit again & then use a bearing retaining compound to seal it & help fix it in place. Success will depend on how worn it is

 

[LittleTree]

It doesn't seem to have that much wear on It. I was gonna sell the saw once rebuilt, maybe i should Simply get another crankshaft and leave the experiment for another day on another saw. I read that loctite 620 Is good for sealing and retaining, but It seems not available here where i live. Are there ahy other good High temp retainers? I saw an Arexons One but It Is guaranteed till 175°c, don't know if It Is enough on a husky saw.

 

[quattro.pilot]

That crankshaft is worn too.. When the bearing got spun it also wore down the crankshaft by microns where the inner race seats, which is why there is no longer a interferance fit. I have the exact same experience with a 242xp ..

In my opinion unfortunately the crankshaft is unusable, I would not put it in any chainsaw and I would not try to use loctite style sealants to "stick" the bearing to the crank. Those bearings see the abuse of heat, vibration, chemicals, and torque. It is sucky and added expense to find a GOOD condition used crankshaft (or buy cheap China.... your choice) but for me that is the only proper solution to this problem.