1979 RM125 need advice on Transmission Bind

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10/29/2018 7:28 AM

After assembling the transmission before installing a new output sprocket, the output shaft was free to spin.
Once I tighten the nut on the output sprocket. I now have a slight bind, when rotating the sprocket, I can rotate the sprocket by hand but feel a tight spot. I have to push a lot harder to rotate it.
I need advise if I need to take it a part or not and what could be the problem.
Thank for your help.


10/29/2018 5:48 PM

photos? Shift through the gears correctly?


10/30/2018 9:06 AM

If the clutch is on the right side you need to rotate the clutch shaft clockwise while you maintain pressure on the shifter until it falls into gear. Repeat this process every time you shift it.


10/30/2018 1:05 PM

There’s 5-6 possibilities,,, but if you installed a new countershaft bearing, it’s possible you got a spec of dirt, or aluminum shaving when driving it in case under it. The smallest .001-.002” particle preventing the bearing from being fully seated or cocked the smallest amount will lead to snug spot after tightening the sprocket nut. You could tap on other side of shaft where idler gear is, plastic hammer. This will put force through tranny to the counter shaft bearing and maybe square it up in its bore. Light taps...


11/5/2018 6:12 AM

Thank you for all your help.
I have not yet been able to try anything.
I did install a new counter shaft bearing.
If tap on the shaft does not do it, Will if have to come apart or can i use it the way it is?