550xp mkii needle bearing conundrum

[Trailoftears]

Also,as an afterthought,given metal or plastic experiencing heat, I'd tend to put my money on metal coping rather better than a plastic structure given the tiny thickness of the structure.

[Trailoftears]

I suppose a good plan is to keep a beady eye on their condition+keep a couple of spares for all your saws to hand.I have to put my hand up and confess they are mostly out of sight/mind until I replace a sprocket!

[spudulike]

I guess you have measured the crank diameter where the bearing runs compared to where it doesn't, inspected the crank surface it for pitting and checked the drum bearing surface for pitting and wear. I see you said the clutch has been replaced so that should discount this as the problem.

Lubrication shouldn't be an issue as the grease tends to just fly out on the first run but wear in the components may well cause issues.

[Sviatoslav Tulin]

20 years, I never grease any needle bearing, never had any problem. Hovever I do replace them once per year, no matter condition, on rarely used Chainsaws once per 2-3 year. If it was my saw, I'd be checking crankshaft if its OK, i check oiler, and replace clutch, drum, rim assembly and probably bar and chain as well, just for sure, YA clean a brake mechanism as well,usually complex methods work well, however they more costly. 

[adw]

The only time that bearing is doing anything is when the saw is idling with no chain movement, when the chain is rotating the clutch, drum and bearing are all turning together so the bearing is doing nothing, so whatever is happing to the bearing is happening at idle, looking again at the pictures of the broken bearing it appears blue from heat, I am not aware of the bearing cage being plastic, so as I see it it’s either a faulty bearing, faulty drum both of which could be creating tight spots, damage to the crank journal where the bearing runs, or working practice.

[stewmo]

Trying to get the drum off the needle bearing and shaft.

Absolutely no movement whatsoever. Guess as the bearing has failed spectacularly it has wedged itself between shaft and drum. 
Any ideas for removal? I’m stumped. 

Thanks for all the comments 

[peatff]

41 minutes ago, stewmo said:

Any ideas for removal? I’m stumped. 

 

Vice grip slide hammer.

[pleasant]

Never grease these bearings....ideally should go on dry or the very least a light spray of WD oil. Grease attracts grit and shoite which just acts as a grinding paste on the crank. I repeat never grease them.

[5thelement]

31 minutes ago, pleasant said:

I repeat never grease them.

I grease mine on all my saws once a week, never had any failures or issues in decades.

[pleasant]

10 minutes ago, 5thelement said:

I grease mine on all my saws once a week, never had any failures or issues in decades.

That's fine........but I see about 6 a year needing new cranks or seized bearings on certain saws. Husky did used to allow for greasing/oiling via a hole in the end of the crank, so not all are the same. but generally I wouldn't recommend it for saws where they don't make a provision for greasing.

Edited November 11, 2022 by pleasant