click here for full size image

you can see where the spline from the rear end unit goes, yes? Below is a blow up of the spline area. its not a great picture, but you can see where the female spline is supposed to be (and is, on the very edges of each side). If you look closely enough, you can see that the interior of the spline (the mating area) is totally stripped, down to a machined looking surface.

click here for full size image

I know this is not a common failure of the Concours, and i asked the almighty COG listserver what the likely cause may be, and i've come up with 2 thoughts.

1. the spline was not lubed, and it failed. I have never personally lubed it, as i have not owned it that long yet (havn't replaced a tire, which is when the lubing would occur), and i obviously have no way of knowing if the previous owner ever did. Though it was an otherwise well maintained bike, and the driveshaft spline was well lubed...

2. faulty part. Perhaps the heat treatment of this particular spline was not correct? it makes sense to me, particularly since the mating male spline looks fine.

Whatever the cause, lets just hope its fixed!! i replaced it with a new cush drive.

back up to 5/28/98