Transmission grinding!

Bhawkins854

Member
I rebuilt my transmission 2 seasons ago due to a failed mainshaft bearing (was hearing loud whining or whirling noises while letting off the throttle as the bike slowed down). The bike has a 6 speed baker, I replaced every bearing in the Trans with either koyo or SKF bearings. Haven't had any issues since. I was riding today and hammered the throttle, heard a bang from the transmission/primary and the bike started to surge almost like it was missing gears. I pulled off the road and could hear a grinding noise from both the clutch area and trans, noise goes away when clutch is pulled in. Makes a awful noise like rocks in a can when it's in nuetral, limped it home in 3Rd gear. Pulled the primary off for a quick inspection, chain is a little loose but not bad, pulled the pressure plate and clutch plates, clutch hub nut is so tight I couldn't get it off yet. Drained my transmission fluid and it's clean as a whistle, no shavings to be found. Pulled the trans upper cover off and cannot see any issues with the gears while I spun the mainshaft. I'm waiting on getting my impact gun to take the hub nut off and check to mainshaft. Any ideas what this could be?? Wondering if this loud grinding noise could be a bearing again since there's no metal shavings and the gear teeth all look intact, doesn't sound like the bearing noise I had before.
 

bfitz

Member
Might not be the same thing ...but several years ago I snapped the main shaft...after Carls Speed shop (don't ever go there) rebuilt it ...about 1500 miles later I had a grinding noise...turned out the set screw had come loose on one of the shifting forks...basically grinding on the gear.
 

Bhawkins854

Member
Looks like I'm missing a roller bearing for my 3rd gear....wtf! Pulled by bearing door and started inspecting, no sign of that cheap plastic bearing anywhere.
 
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