final drive clunk?

[kng254]

Rode to work tonight and while parking I heard a low clunk sound.
I backed my bike into the spot put it up on the center stand and spun the wheel as it spins it gets to a point where it kinda locks up and continues with a little push.
Does this sound like its time to start hunting for a new final drive?
1980 GS1000G

[1948man]

Maybe the disk is a little warped and the brakes drag at one spot during each revolution. If you get a delayed clunk after letting the clutch out, that might indicate the universal joint.

[Dogma]

My first thought is wheel bearings. 100 to 1 more likely than anything else. They're only about $5 each from Z1. You can probably wiggle the wheel from side to side when it's on the center stand, and that would be the smoking gun. The final drives are nearly bulletproof, and your '80 drive splines are one of the good years that don't wear out.

If something is beginning to resist rolling, I'd be nervous about riding it home from work. Rear wheel lockups are no good. Please find another way to get it home. It might be OK for a short ride home, but the consequences of not making it could be severe.

If you've never had the rear wheel off yourself, it's not that bad. BassCliff's site has a .pdf that explains the procedure. Turn the bearing with your finger and you'll see just how bad it is. After that, it's just bearing replacement. Here's the best video I found for the procedure. I don't think any GSers have written it up. There's no need to use heat. Just make sure to drive them in and out evenly, without letting them get cockeyed in the bore. And don't hit the bearing's inner race when you're installing it.

[Steve]

Another possibility that has not yet been mentioned is the universal joint at the front of the driveshaft.

It could be the u-joint itself or loose bolts that hold the driveshaft to the output flange on the engine.

.

[dr_fosg8]

I agree with Steve. Had the same problem a while back on mine. Pulled back the rubber boot that covers the u-joint up by the motor and I had a bolt that had completely come out! No good at all. That bolt was bouncing around inside there and every so often it would catch between the u-joint and the motor.

[Dogma]

Yikes! Easy enough to pull the boot back and have a look. Check it all, eh?

[kng254]

Well instead of riding home this morning after work (68miles) I decided to go to my parents house (8miles) and pull the rear wheel and see what i could see and heres what I saw.
You can see from the pics that three of the six bolts backed out and were rubbing and two of them bent
So I removed all six and replaced them with new bolts applied some loctite and bent the tabs a bit more than they were
Also applied some grease to the splines didnt have any moly 60 so I used red bearing grease figured something is better than nothing
Also pulled back the boot everything looked good

thanks guys for your help