So my middle gear bearing siezed...

[zhagg]

The gears are destroyed and bearings look black with heat... Happened while I was riding on the freeway. There was nothing catastrophic, it felt like my clutch just disengaged...

I feel fortunate that my rear wheel didn't lock up or something like that due to the issue. I have a couple questions though...

Why wouldn't my engine stall if the middle gear bearings are locked? I had the clutch engaged and the tranny sounded like it was engaging into the gears...

Is it possible to have been kicked out of gear when the middle gear shaft stopped spinning upon lock-up?

I removed the engine and took the oil pan off to inspect. The gears look fine, they shift smoothly, the output turns and feels engaged with the rest of the gears etc... I just don't understand where the disconnect would be between the engine and the transmission with a frozen middle gear...

[randy]

Something must have snapped...

[xschop]

Check your middle drive gear....weakest link (fuse)

Funny this discussion was just up recently....
Check your Middle drive oil people....

[Brian_D]

Funny this discussion was just up recently....
Check your Middle drive oil people....

I just checked, and none of my middle drive oil people were wearing pants!

[DGXSER]

Something had to have broken. The crankshaft turns the primary chain which turns a shaft with a gear on the end that the clutch engages with when installed and turns one side of the clutch. The other side is splined onto the shaft of the main transmission shaft and gears. Those are constantly turning the countershaft which constantly turns the middle drive and of course the drive shaft and final drive. So if the middle drive lcoked up, clutch or not, it would lock up the rear wheel inless the gears got eaten in the middle drive or the drive shaft snapped.

Over all, I'd just be happy about it and count my blessings.

[DiverRay]

The gears are destroyed

That is the reason the bike didn't lock up the rear wheel. The middle drive gears are now shafts, and can spin without spinning the "connecting" gear. Time to find a new middle drive, and keep and eye on the oil level! I, and a lot of other riders here, use synthetic oil in the middle and final drive. I like the Red Line 80W-90W, others use Amsoil or Royal Purple.

[zhagg]

Thanks for all of the replies! I don't have any excuse for not checking my oil level.

So, I understand why the rear wheel didn't lock up (because of the shaved gears (you wanna see them...? or should I spare you?)

The shaft is still intact and the bearings are seized... When I crank the engine, the drive axle still turns and I've tried to hold pressure etc. against it (with MG unit out) and it seems to turn right along with the engine in all gears... Would the trans pop out of gear once the MG shaft seized and locked up the output gear from the trans? I figured it would have just locked up the tranny and the engine would stall...

Anyway, that's the situation. Waiting on MG now. I'm going to just throw it back together and see what happens..

[RODS454]

Show us the gears!!!!!!!!

I want to see them. Question DiverRay, when you changed to synthetic oil, did you flush out the old oil with anything? Or did you just drain and replace? The reason I ask is because my final drive oil is very dirty, and want to know if it is better to flush it out or just change. Sorry if I highjacked the thread.
Thanks, RODS454

[Guy_b_g]

When I used to belong to another forum a while back we had a "hall of shame" forum where we would post pics of various mechanical failures, and usually also the cause of the destruction...broken cranks, shattered gears...etc. I wonder if the Administrators would consider something similar here?

[randy]

Guy, that would be a hoot. Why not just start one in Idle Talk?

[CatatonicBug]

The reason I ask is because my final drive oil is very dirty, and want to know if it is better to flush it out or just change.

Just drain and replace. Make sure you do both the middle AND final drives.

[DGXSER]

If you drain your final or middle drive oil and it looks very dark and dirty, I would recommend putting some brake cleaner or the like into there (not carb dip) and drain that back out of it. Then add new fluid of choice. No need to clean just to change from regular to synthetic though.

[Guy_b_g]

Guy, that would be a hoot. Why not just start one in Idle Talk?

Two things come to mind..

I was just thinking that a permanent forum or topic would be better so it doesn't keep falling off the map over time.

Second...I haven't broken anything yet..

[skids]

My 1st middle gear oil change in the cherry bomb showed a thick chocky looking substance at the bottom. Ash? Of course I replaced it with synthetic gear oil.

[zhagg]

Here you go...