counter shaft oil seal small leak.

[daniel deblanke]

hey friends.

rebuilt my 650 in the fall, and have been intermittently seeing a tiny drip AFTER riding.
I pulled the cover, bent the washer down, and torqued the nut over the small sprocket. Thought that would fix it, but the small drip persists.

Should I take off chain, nut and sprocket and check the seal? (already have one in hand) or is it something that i should put more miles on the bike to get excess oil off chain? (or clean the chain)

as you can see - it is real clean under the cover, and the pushrod isn't leaking either.

bike only has 600 miles on it since rebuild.

thanks

DDB

 

[yamageddon]

Tightening the nut on the sprocket won't close the seal. The sprocket can't go any further on the axle and does not close the seal because it is not mounted against a seal. It's a very tiny drip, you're sure it comes from that seal and not from a gasket or something? I would clean all surroundings, take it for a ride and check if it actually comes from there. But it's not much. Mine does the same...for a while now, but it's so little that I don't think it's worth to take it all apart. That little drip looks a bit greasy does not look like fresh oil. Maybe it's from the chain.

 

[grizld1]

There is an internal seal in the countershaft bearing. When the sprocket nut loosens (and it does, in spite of the tab lock washer), the bearing will pass oil.

 

[yamageddon]

There is an internal seal in the countershaft bearing. When the sprocket nut loosens (and it does, in spite of the tab lock washer), the bearing will pass oil.

Ah thanks, didn't know that. When it's loose it's worth trying of course, but if it's already tight the way it should, it should not leak I suppose? Over tightning won't solve it then I guess?

 

[xjwmx]

Overtightening won't fix anything. If you think it might help it just means something is wrong you haven;t discovered yet.

 

[yamageddon]

Overtightening won't fix anything.

exactly

 

[Ozboy]

Just had a large leak on my bike after a ride and found the main nut loose even with the tab bent over. Crazy!
Took it off checked the seal was ok and loctite torqued it back up and been fine since. Did the clutch seal and bush while i was there too.

 

[5twins]

And tightening the nut means making it really tight. This is one of those torque specs that changed multiple times over the years of production, not sure why. It ranged from a low of about 36 all the way up to nearly 95 ft/lbs. Best results seem to be had using the higher value. There is a chrome steel sleeve that fits over the countershaft and into the seal. That is what the seal works against, usually quite well. What you're trying to seal up with the really tight mounting nut is both ends of that chrome sleeve. It presses against the inner race of a bearing inside the motor and against the back of the sprocket on the outside. If the nut is loose, oil can get in between the shaft and sleeve, and run out along the shaft. And it runs out pretty good, lol.

 

[xjwmx]

I need to study just what happens when the nut is loose. Visualizing it in my mind I think oil could past the inside of the sleeve where the splines are. It must seal against the bearing inner race. I wonder how much crushing force it can take there and what's holding it one the other side. At any rate, if it isn't tight it will leak for sure. A dot of blue locktite plus the tab will keep it on.

 

[gggGary]

Couple more points on the sprocket. If you are going to retighten; do the full monte, remove chain, nut, tab washer, sprocket, and the steel sleeve, clean, clean, clean. Check for any burrs or rough spots on sleeve, sprocket, nut, sand on flat surface or touch up with a file as needed, lightly grease and reassemble. The tab washer is very fussy about location, flatten, file, carefully align and watch it stays there as you tighten the nut with the recess facing in. Madness had a drip there; turned out if was the top starter gearcase bolt that holds the shifter shaft protective cover. Cleaned the case thread with spray cleaner and compressed air, CAREFULLY used a bottoming tap, cleaned the hole again, went from a 25mm long m6 bolt to a 30mm bolt, leak stopped. There was just enough depth to tighten that 30mm bolt, double check your depth by installing it without the shaft cover make sure it can go deep enough to snug up. As always be super careful tightening 6mm bolts. On other XS, I have had to remove that starter gearcase cover and replace the gasket to stop a leak.

 

[daniel deblanke]

So I changed the seal, and the problem persisted.

Put some miles on the bike and finally went back in to check, and the push rod seal had gone bad.
actually looked like the chain was rubbing the seal slowly, and the leak was pretty nasty.

Cleaned it all out replaced BOTH seals again, and whiped down anything that could see spray from the chain.



Went for an hour long ride and pulled the cover. Seals are dry, with minimal some residual spray from chain.

I was a little more liberal with the yamabond this time and made sure that the seals were pushed in good and even.

For the pushrod seal I made sure it was into the case a little, and that the rod was completely surrounded by the seal rubber.

Will ride a bit longer and just check the tire (for splatter), etc.

Thanks for all the help

 

[mrtwowheel]

Chain rubbing on seal...…...that front sprocket looks like a goner.

Scott

 

[daniel deblanke]

Chain rubbing on seal...…...that front sprocket looks like a goner.

Scott

Well the chain was rubbing on the push rod seal, which wasn’t pushed flush with case, the counershaft seal I just pushed in wonky, and didn’t put enough yamabond on.....

Why is the sprocket a goner?

 

[mrtwowheel]

Looks like a wide space between teeth, and there's not much tooth left. Do the teeth look hook shaped to you?

Scott

 

[daniel deblanke]

Well shit, I’ll order another! Thank god I’m a pro a taking this fracking chain off.