crankcase needle bearing problem

[jaguar]

3 months ago I replaced all the bearings and seals in the crankcase since the needle bearing (the one in front of the output shaft left bearing) #92046-026 had stopped spinning and the shaft was eating through one side of it.
Well the groaning has started again and after taking the clutch cover off I can manually move the clutch up and down with more movement than just the big right side bearing will allow which means the little needle bearing on the far side is going out again.
Any ideas as to why and how I can make its lifespan more than 3 months? thanks

 

[beefking]

Not really sure why just that particular bearing is going before the rest, but...maybe the shaft is scuffed up a bit, or the outer race the bearing sits in?

How often do you change your oil? Do you abuse the clutch alot? I guess if you leave the same oil (use a good 80w gear oil , Belray gear-comp is great in the kdx imo) and abuse the clutch alot, those fibers will eat the smaller needle bearings.

 

[jaguar]

I use a synthetic 15W50 4 stroke oil by Motul.
Its the only thing available that I've found to make shifting smoother.
I guess I need to search farther and try to find a 2 stroke oil although I really don't know the difference between the two or if it makes a difference.
The shaft and race seemed in good shape. Seems like an awfully small needle bearing to handle such force from the gear shaft.
I change the oil probably twice a month lately since I haven't been dirt biking since my hands still hurt from a street accident. I ride maybe 10 miles a day on the street.

 

[jaguar]

I think I know why.
The bike has always had a problem of leaking oil from the shaft driving the countershaft sprocket. Today it was really leaking bad and so I thought it might help to put a second o-ring inside of the collar. It stopped the leakage and when I looked at buykawasaki.com it showed there was supposed to always be two o-rings there although my owners manual only shows one.
So probably the bearing went as a result of long rides with low oil level due to leakage.

 

[70 marlin]

My feeling's on your bearing. Either it was a factory defect. Damaged in shipment or installed incorrectly. Go get your self-a new shaft & bearing and try again. For case bearing's I like to use a hydraulic arbor press. Then be careful and do it slowly! Make sure you only push on the out side race. Good luck!

 

[beefking]

That is possible Jag, due to low oil levels. But to clarify you only have to use 2 o-rings if you "have" to; if one does it then that would be fine too.
PS marlin, this needle bearing isn't pressed on, it just slides in.

Hopefully this stops the bearing from goin anymore jag!