Clutch Shaft Problem

[trbig]

I have no idea what's going on here. This motor was purring along fine. I had done the gear fix on it, but then it had shifting problems. When I tore it down, I found the spring clip had come off the end of the clutch cam..







I figured maybe this was a fluke. I installed the clip back on, put fresh bearings and seals in the motor, mounted it in the bike and went to install the clutch basket and noticed this.... Sorry about the blurry picture...


VIDEO






There is a LOT of sideplay on the clutch shaft. The video doesn't really show how much, but it moves almost as much as the shaft nut is thick. The other motor I just took out has no sideplay. I'm convinced that these two problems are connected.

I am now pretty sure that I'll have to pull this motor AGAIN, split the cases AGAIN, then split the other motor also to get the parts I need from it. I'm just not sure what could be going on. The bearings in the case on both ends appear to be fine. Guesses or suggestions?

Tod

[81xsproject]

Is your comparison motor without its clutch basket also?

[79XS11F]

If you have that much side play perhaps the pin, at the other end under that bolt, is worn out or not in place in it's slot properly. Check it
Rob

[trbig]

Is your comparison motor without its clutch basket also?

Yup.


Rob, not understanding what you're saying.

[79XS11F]

Clymer manual, page 137, top right & page 138 photo 104. Check the condition and placement of the shift cam detent.
Rob

[trbig]

The shift cam is fine. I installed that circlip back on and it worked fine. It's the main shaft that the clutch basket goes on that has the sideplay.


Thanks though.

Tod

[79XS11F]

If that detent pin is in place there shouldn't be much side to side movement of the shift cam.
Rob

[trbig]

The shift cam isn't moving side to side. It's the main shaft.


Tod

[GNEPIG]

If the circlip between 2nd/3rd gear pinion and 4th gear pinion comes loose from it's groove your shaft will move over until the gears touch.

[trbig]

Well... if I install the basket and torque the nut down, it would take away any sideways movement. So, if this was your motor, would you take it back out, re-split the cases and find out what's up, or just run it?

I'm leaning towards the exploratory heart surgery as bad as I hate to.


Tod

[79XS11F]

I have an engine in the garage with the cases together but all removable components removed. I just checked that clutch shaft and there is no side play what so ever. Installing the clutch basket may indeed remove the side play that you have there but that is only moving the shaft out of its intended position. I would be inclined to fix this while it's easier to do.
Rob

[XSPastor]

I seem to remember the same side play until I installed the clutch. I would insall the clutch and check if the side play goes away.

Tim

[trbig]

OK.. Came home from work and got after it. 3 hours and 3 Crown and Cokes later... I removed the current engine from the bike and got them both thrown up on the bench together. The old engine I took out has no sideplay whatsoever either in that shaft. I split the cases on both motors and found the problem. Apparently the bearing on the clutch basket side is pressed onto that shaft. The bearing keeps the shaft stationary and a C clip on the outside edge of the bearing sits in a groove in the case to hold it in place. Somehow, this bearing has come loose from the shaft, letting it slop back and forth.


VIDEO....




Here's a pic of the old motor's shaft... there is no play in this one. You can see the C clip on the bearing and the groove it sits in better than the video.




The only thing I can think of that would cause this would be vibration in the shaft somehow?? The bearing feels snug still between the shaft and the inside of the bearing, but maybe not at several thousand rpm? lol. I'll swap the old one into this motor and stick it back together tomorrow.


On a side note, we had installed new crank bearings on this old motor. We didn't plastigauge anything... just put what was in it back in and rode. I noticed a slight knock right away... even though SOME people said I was hearing things. (Ahem Kat...) The crank must have had some wear to it also that didn't get accounted for. This is one half of one bearing from the left side. If you ever see a slight copper color in the bearing, you have rubbed through the bearing surface and it needs replaced. If you have run through the copper color so much that it has started to shave the bearing and ball it up on the sides of it... you may have a problem! Sure was lots of pretty glitter in the pan too! At least it didn't spin the bearing like the first motor I had did. This motor probably didn't have 5,000 miles on it since the new bearings were installed.





I hope this helps someone in the future. Maybe this clutch bearing I pulled it apart for would have been fine?? The clutch basket bolted on took all the slack out, but this bearing became un-mated from the shaft for some reason.. I'm betting some form of vibration. Maybe a high run-out/ slight bend in the shaft. I'm glad I went ahead and fixed it.


Tod

[79XS11F]

By the looks of things it worked out OK that you had to go in to it again. You think this damage to the bearing was caused by journal wear causing vibration or the bearing being to tight?
Rob

[trbig]

No idea.. neither the bearing or shaft seem gaulded or damaged in any way... just not connected any more.

I have everything back together and the motor back in the bike tonight. I just need to install the head, cams, exhaust and carbs. I may get it running tonight.. but it may be tomorrow. It's hot and humid and this fat boy is sweating his arse off! This sure would be a lot easier with some pneumatic tools.. lol


Tod