A new theory

[Rocket Scientist]

Starter tight, no cat, drained diff onto a magnet wrapped in white cotton, no swarf. Removed rear wheel cush drive and bearings all good.
Removed diff looks good. no end float and back lash seems acceptable. Spline was rusty brown which amazed me as my tyre is only half worn and I put lots of Molycote on it when I do it.
Will replace all the wheel bearings.
Probably remove the swing arm tomorrow to check movement in damper shaft if I get time to make a lifting attachment for my trolley jack at work tonight!!!
I read somewhere here that Avon tyres make a bit of noise when they are worn it couldn't be that could it? noise mainly happens at 120kph and sometimes when decelerating at around 50kph.
Tyres wear very flat around here as we have very straight roads.

Used moly looks like rust. Kinda disturbing the first time you see it. Perfectly normal.

 

[Doc Roc]

Used moly looks like rust. Kinda disturbing the first time you see it. Perfectly normal.

The moly I put in the cush drive never turns brown, thats what freaked me out.

 

[Rocket Scientist]

The moly I put in the cush drive never turns brown, thats what freaked me out.

Ya, come to think of it my cush drive moly stays moly colored. Hmmmm...

 

[Doc Roc]

Got the swing arm off, universal is fine, front spline is still lubed with wet moly. No movement in damper shaft. Damper shaft is hard to turn by hand but easy if I attach the drive shaft. Does not make any really strange noises apart from it having helical cut gears I think. Really don't know if I should go any further or just put it back together with my fingers crossed.

 

[Doc Roc]

May have found the problem. Cleaned up the rear spline of the drive shaft and found it it 50% ****ed. My fault entirely as the diff I have now was a recall back in 05 because of a seal problem. When I received the replacement diff I cannot remember getting a packet of Moly to refit it, but they did send a new bolt and locktite for the disc caliper pin??? I have always lubed the spline with molicote since I found out you need to do it but there was a time where it did not happen. Do you think that this extreme wear would cause a noise that I am worried about???

 

[Rocket Scientist]

May have found the problem. Cleaned up the rear spline of the drive shaft and found it it 50% ****ed. My fault entirely as the diff I have now was a recall back in 05 because of a seal problem. When I received the replacement diff I cannot remember getting a packet of Moly to refit it, but they did send a new bolt and locktite for the disc caliper pin??? I have always lubed the spline with molicote since I found out you need to do it but there was a time where it did not happen. Do you think that this extreme wear would cause a noise that I am worried about???

It looks like to your spline is close to 25% gone. I bought my bike used and the splines had run dry before I got it. Mine were 50% gone. They weren't causing any symptoms or noise but I replaced the shaft and diff before they failed. I would run the one you have without a second thought. I'm not trying to shoot holes in your ideas (well actually I am). I just want to see you get to the root cause of the problem. You've got a lot of work into it now, and it would be a shame to put it all back together and have the noise still be there.

 

[TheKid]

I didn't realize we were suppose to lube the cush drive. Is this the rubber you are lubricating? Or am I confused (again)

 

[Rocket Scientist]

I didn't realize we were suppose to lube the cush drive. Is this the rubber you are lubricating? Or am I confused (again)

Hi ya Kenny ! It's the splines on the cush drive (that insert into the bevel box) that need to be lubed. Heh,heh I said "insert"

 

[Gregger]

Hey Doc,

Don't mean to change the thread but that is a slick jack attachment you have there fastened to the bike. Is the jack easy to remove once everything is back together and lowered?

 

[Doc Roc]

Hey Doc,

Don't mean to change the thread but that is a slick jack attachment you have there fastened to the bike. Is the jack easy to remove once everything is back together and lowered?

Zoom in and you will see that it is attached to the swivel part of the jack by 3 cap screws just clamping it there. removes in seconds with an allen key.