2012rt signs of failing drive shaft

[jjpen]

While riding along it feels like the rear tire hits an object in the road that is not there.  Just a little bump in the bike.  I am guessing a bad drive shaft but how can I know for sure?

[dirtrider]

13 minutes ago, jjpen said:

While riding along it feels like the rear tire hits an object in the road that is not there.  Just a little bump in the bike.  I am guessing a bad drive shaft but how can I know for sure?

Evening jjpen

 

It might not be the drive shaft it could be other things like the final drive crown bearing. 

 

The only way to know for sure if the drive shaft is OK is to remove it & inspect it. 

 

Put the motorcycle on the center stand then grab the rear wheel at top & bottom then try twisting it to see if it has excess play. Then do the same at front & rear of wheel. 

 

You might possibly be feeling a sticking drive shaft on the splines if the problem happens when you hit a dip or do something to cause the rear suspension to move enough to get it to move.

 

In any case you need to get it checked out just to be sure. 

[jjpen]

Well the crown bearing has no play.  I listened to the swing arm with my stethoscope and sure enough I could not hear or feel anything unusual.  Other than the driveshaft what could it be?

[dirtrider]

5 minutes ago, jjpen said:

Well the crown bearing has no play.  I listened to the swing arm with my stethoscope and sure enough I could not hear or feel anything unusual.  Other than the driveshaft what could it be?

Afternoon   jjpen

 

If you could define the input from the rear in a little more detail we might be able to tell you something. 

 

Is it only one input? Or multiple inputs in a row?  If so how often does it happen?

 

If more than one input at a time is it wheel rotational speed or drive shaft speed (about 3 times wheel speed).

 

Have you checked the rear wheel for being tight?

 

If you have side cases or a top case then remove those then ride it &  see if the problem goes away.  

[jjpen]

I checked the rear wheel and it was tight.  The bump is always one bump only.  It happens three or 4 times on a 40 mile ride.  I left the luggage at home, took a 40 mile ride and not a single bump!  If the luggage is my problem how good is my luck?  Thank you dirtrider

[dirtrider]

30 minutes ago, jjpen said:

I checked the rear wheel and it was tight.  The bump is always one bump only.  It happens three or 4 times on a 40 mile ride.  I left the luggage at home, took a 40 mile ride and not a single bump!  If the luggage is my problem how good is my luck?  Thank you dirtrider

Evening  jjpen

 

You don't have something loose or rolling around under your seat do you?

[jdub53]

14 hours ago, jjpen said:

I checked the rear wheel and it was tight.  The bump is always one bump only.  It happens three or 4 times on a 40 mile ride.  I left the luggage at home, took a 40 mile ride and not a single bump!  If the luggage is my problem how good is my luck?  Thank you dirtrider

 

The panniers on my RT have more mounting point play than any panniers I've had on six previous BMWs. The RT panniers only get mounted/used about twice a year when I actually have something they need to carry on a trip, so at that time they're loaded with weight which helps to mitigate the mounting point play.

 

From what you posted, it appears possible the (empty?) panniers themselves are the source of your noise which I could believe.