Need help - bike won't move while in gear

[rteam2]

This just happened last night with my 81 GS650GL. Rode 20 miles, stopped for gas. Started engine fine, kicked into first gear, heard grinding noise & bike wouldn't move under own power. Seemed like grinding/shearing/gears not meshing was coming from rear wheel area, perhaps on left side. Bike starts fine and seems to move through all gears. Indicator shows gear selection as well. Just won't transmit power to rear wheel. I can put it in gear and release clutch lever, engine continues to run as though it's in neutral. I had to push it a mile to get home, and I could have done so with the engine running in any gear - it would roll just as easily as in neutral.

I'm fairly mechanical, but this is my first bike and my first real issue with it. I've had it for six months and I don't know if PO did any clutch or rear drive work.

Not sure what other info I can give you guys, but I'd be interested in your opinions or direction. My gut tells me it's an issue in the final drive, but I suppose it could be a clutch issue instead (or also). Someone recommended draining the final drive oil to see if there are shavings. I guess that's easy enough, but is that where I should start?

[bmac]

Rear splines

I would suggest taking off the rear tire and look at the splines on the drive gear. Possible teeth are gone. Bob

[fishfarm]

I agree, the rear splined hub would be my guess also. Check out this thread for more info:

http://www.thegsresources.com/_forum/showthread.php?t=149097&highlight=check+splines