A few months ago I replaced the countershaft seal with a new OEM one (93102-35109-00). Noticed the bike was still dripping on the floor and had oil running down the kickstand. :whatever:
Pulled the left engine cover and sprocket and discovered I still have a leak there. The OD of the seal is dry. Looks like it's coming out around the collar, but not sure if it's seeping out of the OD or from the ID and spline area. The collar doesn't appear worn and the inner lip of the seal is in good condition. Anyone have any tips for resolving a leak like this? Hate to throw another $20 seal in there and get the same result.
The other seals on that side that were replaced are all dry (clutch pushrod, shift shaft, neutral switch). :thumbs:
rd400_trans_parts_CSseal.png
The seal, #34 only seals the OD of the spacer, #35. Oil can creep along the splines of the countershaft and through the ID of the spacer, #35. The only 'seal' formed then is the metal-metal interface between the outer face of the spacer, #35, and the back face of the C/S sprocket. Make sure that interface is smooth and flat. Maybe try some yamabond??? :twocents:
One of the manuals I have, either Rd, Banshee, RZ or Suzuki GS mentions case sealer on the collar #35 so I always put some in there.
^this
is it possible to fit a small O-ring on shaft directly behind counter sprocket?
Thanks for the suggestions. When I have a chance this weekend I'll check the outer face of spacer for flatness and put a little Yamabond on there. :thumbs:
A little sealer on the lock tab washer and threads too.
put it in the inside face of the spacer. take spacer out and put it there, then reinstall. it'll never make it down.
if you know somebody w a lathe have them bevel the id at the bearing side and use an oring there.
Quote from: RDnuTZ on February 27, 2026, 11:58:23 AMis it possible to fit a small O-ring on shaft directly behind counter sprocket?
Would need a groove machined in for the oring like a yz
Kaw's have an o-ring that gets smash smooched for spline sealing.
Some Yamahas like mid-1970s singles do too on primary side of crank between collared end of primary gear and main bearing. The O-Ring is #17 in below parts blow up diagram. It is for 1975 MX400B.
https://yamaha-motor.com/parts/diagram/13301662/305836756