"Clunking" noise coming from rear drive area

I started feeling an odd sensation coming from the rear drive after shifting and re-engaging the throttle. If felt and sounded like the drive line was struggling, perhaps skipping a beat when power is reapplied.

I put the bike on the center stand, and let the bike run in 1st gear. There is clearly a clunking noise coming from under the rubber boot between the swing arm and the final drive.

I swung the drive out of the way this evening and water poured out of the swing arm area where the drive shaft engages the final drive. The drive shaft internal splines are clearly worn but nothing is broken. The final drive external splines are also worn a bit but nothing is broken. The final drive rotates freely without any sound.


Any ideas?

I have a 2004 K1200LT that I bought used in 2008 & the first time I removed the FD the swing arm was full of water because a dealer had not got the swing arm boot sealed when they changed the transmission output shaft seal. Over a 100,000 miles later a u-joint failed because the water had washed out the grease.

What is the model & year of your bike ?.

saddleman said:

I have a 2004 K1200LT that I bought used in 2008 & the first time I removed the FD the swing arm was full of water because a dealer had not got the swing arm boot sealed when they changed the transmission output shaft seal. Over a 100,000 miles later a u-joint failed because the water had washed out the grease.

What is the model & year of your bike ?.

Click to expand...

It's a 2010 K1300GT with ~ 61,000 miles on it.

U-joint? Pull the driveshaft out and check them.

there is so much play in the driveline when unloaded such as when running in gear on centerstand that it scares most folks. Not a true reading on driveline health.

Ideas on the sounds? I've had the bike since new, this sound is definitely recent.

I would still pull the driveshaft and check the u-joints. I believe there is no locking clip on the tranny side and it should come out without much effort. My K12S slid out when I dropped the FD the first time.
There is a joint where you hear your noise

a failing joint will do funny things, noise wise and smooth driveline performance. One that destructs under power is not a good thing. I had a recent failure on my GSA that I caught before a trip during a service. It would stop every 90 degrees when trying to roll wheel...lucky to find before it came apart.

I second Henzilla's comments. I did not have my K13S long enough to experience anything like this, but your description is very similar to what I had on my K1100RS. As stated, a failure of a u-joint while under power is NO FUN!!! I do speak from experience, but thankfully it broke loose and spun up only 3 miles from home, it did not cause a siezed wheel or transmission. Inside was a PILE of metal shavings and busted U-joint parts as this had been progressing for some time and I did not recognize it. Prior to the failure, a knowledgable buddy and I actually put it on the center stand and put it in gear like you, then placed a hand on the tire to give some resistance. The sound would go away, then come back with no resistance, we had no idea what it was and at the time had not heard of K bikes having U-joints fail. After a couple of months it got to where backing down it really thumped, but accelerating it was quiet, and generally thumped on steady throttle. Then one day, I added just a little gas hoping to get home as it had started 'slipping' and not sending power to the wheel...it just broke loose. It required a new drive shaft and a new final drive with new pivot pins and bearings. I got most of it used and did the work myself, and still it was costly and took me a while. Definitely get this looked at either by you or by a dealer. As Henzilla notes, it really sounds to me like a failing U-joint.

Thanks for the input, I found a used drive shaft off a k1300gt that will be delivered by the time I get home at the end of the weekend.