Output Shaft Spline Play

[spacewrench]

My 2000 R1100S is running again after my clutch-spline adventure, but there's a bit of a "clack" noise that I don't remember from before, and I have a suspect point that I'd like to know more about.

 

Specifically, when rolling slowly, in gear, at idle, you can pull in the clutch to coast, or let it out to get a very small, lumpy push from the motor.  When you do that, there's a clack both ways, as if there's some backlash in the drivetrain that you're either taking out (to go under power) or letting back in (when you coast).

 

What I suspect is that the front U-joint, which is splined onto the output shaft of the transmission, is not completely engaged.  (When I assembled it, I thought I felt it click over, but now I'm not sure.)  There's a circlip there that holds the front of the driveshaft to the output shaft, but by looking into the little spherical boot at the front of the swingarm, I can move the U-joint back and forth a bit (fore & aft on the splines).  (I think all the length-adjustment of the driveshaft is supposed to happen between the splines at the back end of the driveshaft and the front yoke of the rear U-joint -- the back yoke of the rear U-joint is similarly circlipped to the final drive spline.)

 

 

So, a couple of questions:

 

* Is there supposed to be any longitudinal play splinewise between the front yoke of the front U-joint and the transmission output shaft?

 

* Can I lever the front yoke of the front U-joint past the circlip and onto the output shaft without disassembling the swingarm and/or final drive again?

 

(I tried levering with a stout screwdriver against a wood block, but couldn't get it to click over.  I can apply more force, of course, but would like to know if that's going to get me anything other than damaged swingarm edges and bent screwdrivers!)

[dirtrider]

8 minutes ago, spacewrench said:

My 2000 R1100S is running again after my clutch-spline adventure, but there's a bit of a "clack" noise that I don't remember from before, and I have a suspect point that I'd like to know more about.

 

Specifically, when rolling slowly, in gear, at idle, you can pull in the clutch to coast, or let it out to get a very small, lumpy push from the motor.  When you do that, there's a clack both ways, as if there's some backlash in the drivetrain that you're either taking out (to go under power) or letting back in (when you coast).

 

What I suspect is that the front U-joint, which is splined onto the output shaft of the transmission, is not completely engaged.  (When I assembled it, I thought I felt it click over, but now I'm not sure.)  There's a circlip there that holds the front of the driveshaft to the output shaft, but by looking into the little spherical boot at the front of the swingarm, I can move the U-joint back and forth a bit (fore & aft on the splines).  (I think all the length-adjustment of the driveshaft is supposed to happen between the splines at the back end of the driveshaft and the front yoke of the rear U-joint -- the back yoke of the rear U-joint is similarly circlipped to the final drive spline.)

 

 

 

So, a couple of questions:

 

* Is there supposed to be any longitudinal play splinewise between the front yoke of the front U-joint and the transmission output shaft?

 

* Can I lever the front yoke of the front U-joint past the circlip and onto the output shaft without disassembling the swingarm and/or final drive again?

 

(I tried levering with a stout screwdriver against a wood block, but couldn't get it to click over.  I can apply more force, of course, but would like to know if that's going to get me anything other than damaged swingarm edges and bent screwdrivers!)

Afternoon  spacewrench

 

The usual place for that   clack that you feel in in the transmission gear dogs to slider dogs, as well as some slight gear to gear play & final drive gear backlash.

The transmission is built with more slider to  gear slop in the lower gears to make it easier to shift through the lower gears, they tighten the slop in the top couple of gears to remove some of the clacking & smooth out the drive train as that is where most of the riding is done. 

 

 

* Is there supposed to be any longitudinal play splinewise between the front yoke of the front U-joint and the transmission output shaft?-- Just a little as the circlip isn't a tight fit in the shaft  & yolk slots.

 

* Can I lever the front yoke of the front U-joint past the circlip and onto the output shaft without disassembling the swingarm and/or final drive again?-- Should be able to but you might need the swing arm straight  so you get a straight push on the drive shaft.

 

(I tried levering with a stout screwdriver against a wood block, but couldn't get it to click over.  I can apply more force, of course, but would like to know if that's going to get me anything other than damaged swingarm edges and bent screwdrivers!)-- Depends,  is it already all the way on?????  Is the circlip distorted????  

 

 

 

[spacewrench]

Thanks DR.  The front U-joint spline had too much motion, I couldn't fool myself that it was actually engaged.  Couldn't get it clicked over with a screwdriver, so...

 

I'm no longer intimidated by the final drive pivot pins, plus I knew not to let the front U-joint fall off, so I pulled the final drive, gave the driveshaft a whack to engage the front circlip, then reinstalled the final drive.  Piece o' cake, and it ran smoothly down to fill the tank.  Looking forward to another 100K miles!

 

(Actually, there's one other thing I gotta do: on the front spherical boot between the swingarm and the transmission, the circlip that's supposed to hold the swingarm end in place is out of position.  I guess I'll have to pull the swingarm to fix that, so I'll wait until I get a replacement shock or some other reason to screw around with it.  And I'd like to pull the transmission to check the input splines after 10-20k, but that's a bigger hassle.)

[Jim Moore]

No need to pull the transmission. You can check the splines through the starter hole. Check them every 10K for a while, until you're sure they're not deteriorating. 

[spacewrench]

I put on an extended-hub clutch in this repair, so you can't see the input-shaft splines through the starter hole (all you can see is the outside of the clutch hub).  I know I can check for play through the starter hole (which is probably worth doing) but I'm really interested to see whether there's any erosion anywhere along the input shaft.)