Blown clutch

[mrbuck]

Gearbox out...input shaft and clutch splines dry as a bone BUT undamaged!  The clutch housing is also dry so no leaks to oil the clutch.

Now, what was that grinding noise and the "zinging" sound I was hearing when I decided to pull off the road?  I can only believe it is the gearbox.  I strained the 200cc of oil that came out and could find almost nothing in the form of metal shavings.  

If I turn the input shaft by hand...very easy to do...there seems to be quite a bit of "slop" between the input shaft and the drive shaft (4 bolts) input connection.. Is this normal?  I would say there is 15-20 degrees of "slop" in the output.   Drive shaft and rear drive are not connected.  

Anyone with similar experience?  All theories are welcomed. :-/

[Bob_Roller]

Have you checked the final drive output splines ?

[mrbuck]

I removed the rear tire before taking the drive shaft/rear drive unit loose.  Splines looked good.

[nhmaf]

If you grasp the output flange on the transmission output shaft and turn it back and forth, do you feel like it is engaged/connected to the shaft?

If (hopefully) your gears are still intact, it might be that you lost a lobe/ear on the spring-loaded intermediate shaft inside the transmission.   They don't often break, but if they do it could give alot of noise, somewhat disconnected feeling, yet not alot of metal shavings - provided that you stopped soon enough before things started to grind up.   I've also seen one (Rare) case of the spring actually breaking - the owner was still somewhat able to move the bike on its own power, but it was not at all a smooth ride.

The part(s) I am thinking of are #5,6,&7 in this fiche-




....Errr, oops, sorry for the ridiculously small size... image copied from MAX's fiche library didn't work so well.   You want to look up Diagram#23_0257 in the R65 parts fiche..
http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51897&rnd=04302013

I may very well be wrong on the diagnosis, but it kinda sounds similar to 1-2 threads I looked into a couple years back on another forum.

Fingers are crossed for you, but with so little oil in the gearbox, I assume that there was alot more friction than normal throughout its innards.

[mrbuck]

As I said in the previous post, the input shaft and the output flange,  are connected but with a lot of loose movement.

I will look up at larger diagram in my factory workshop manual and investigate your theory.  Thanks to all for input.  I will visit the two dealerships we have close connections to and pick the brains of their tech staff.

Later.

[Bob_Roller]

At 145,000 miles, I'd say you are due for a transmission overhaul .

[mrbuck]

See initial post...this was done at the same time the new clutch was installed...$1100.

As a wise person said, "If you have a problem money can solve, you don't have a real problem".

Every lesson in life ...and motorcycles...has a cost.  I will stay in touch when the mystery is solved.  Thanks again to all.

Any new ideas?

[Luca]

Any new ideas?

Only think I can imagine is if you didn't have an extra 600cc's of fluid in the swingarm, perhaps somebody filled the transmission from the gear selector input instead of the fill plug.  I'd replace the tech's head with your transmission.

But on a more serious note...

I will visit the two dealerships we have close connections to and pick the brains of their tech staff.
 

I'f you've got one nearby, or don't mind mailing it, take your transmission to an airhead guru instead of just a dealership.

And even if the work was done years ago, go back to whoever rebuilt the trans and make a stink.  The gear oil should be changed more frequently than it was... but the thing should also be filled to the level when it's given back to you.  It's hard to miss leaking over a half a liter of oil.  Worst that could happen is you end up right back where you are now.

[Bob_Roller]

If I remember correctly, you had the threads stripped in the transmission, where the hollow bolt that secures the speedometer cable to the transmission threads into.

Is the small vent hole in the bolt clear ?

Did you place any sealant in the area after finding the threads stripped ?

[mrbuck]

Great memory, Bob. Actually, I checked that and the hole was clear. What would the effect of that had been if plugged?  

I know the vent hole is there to keep the lube from frothing...right?

Since I have the gearbox out I can heli coil the vent bolt and reattach the battery ground which I had moved to one of the coil mounts. That bolt had been held in place by the rubber boot for quite a while.  Can't say I was proud of that arrangement.

[Bob_Roller]

If the hole is plugged, the air in the transmission can't escape when it gets up to operating temperature, it 'pressurizes', possibly forcing oil into the drive shaft housing, if it can get past any seals .

[mrbuck]

This much I know to this point.

*The clutch and input shaft are undamaged but dry.
*There was only 200cc of trans fluid in the gearbox.
*Gearbox experienced false neutrals and difficult shifting.
*The input shaft and drive shaft seem to be O.K.
*Spinning the gearbox on the work bench with an electric drill does not produce any unusual noises.

However, and this is the current question,  should I be able to shift gears while spinning the input shaft? I can not make any shifts but the lever moves.  I checked the shifter on MsBuck's R65 and note that while the engine isn't running it also will not shift on static.

[Luca]

The transmission should shift without the clutch, especially under no load, but you will have to somehow spin it in the process.

If it wont shift with the transmission spinning you could have broken a pawl spring.

[mrbuck]

Latest update..

*Added 800cc of generic 80W gear oil...final filling will be with Amsoil or other synthetic.
*Good news is that by turning the output shaft SLOWLY, not with an electiic drill as some suggested, I am able to shift through the gears with the aid of a small extension on the shifter for more leverage. To do this I would pause momentarily as if pulling the clutch in.
*Also good news is that turning the output shaft slowly I was able to get more of a feel (hearing) for the sounds of the gearbox which was only a slight gear whine near the input splines.
*After reading many posts at this point I may have to amend the "bone dry" statement I first posted.  I have learned that many of the excellent lubes for splines will appear "dry" after a short time and it is the moly in the grease carrier that actually does the lubbing  and not the grease itself.  I am sure this will start a new thread.  If so, all good advice will be appreciated.

Next stop, the Honda shop for some Moly 60.

[nhmaf]

Yes, the moly 60 will dry up and leave only a very, very thin coating on the spline teeth which will provide the necessary friction reduction for sliding.    I *used* to put it on "straight" (Moly 60 paste only and no grease) but I found while the Moly60 microscopic particles usually remain, there is nothing there that really inhibits corrosion.   Now, I mix about equal parts of the Moly60 paste with a good, sticky red grease that I use for lubing my tractor and implements and put that on.   The Moly particles are still there in sufficient quantity to do what they need to do, and the tack red grease sticks around for longer to fight against corrosion.   Still have to be sure to not over-apply to avoid soiling the friction disk.