Hi Pleiades,

don't fret too much about the other linkage bearing sizes unless you have an easy way to find that info out, I don't think that is where my problem lies.

As you were quick to respond on both of my posts seeking info recently I am guessing you are an avid XT forum reader, and I thought I would perhaps bounce my problem off you as it were, in order to solicit your opinion, or indeed that of any others that might be able to help.

The bikes a 26000 mile XT660Z, bought just before Christmas from a guy called Andy in Bristol. He had used it to traverse continental America, so it has obviously seen some use.

I noticed the back shock was knackered when I bought it, but factored that into the equation price wise.

When I got it home, I noticed an pronounced creak from the rear suspension, almost like a crack, crack crack noise when the rear is extended by pulling the bike over on the sidestand. It sounds like a little bearing that's broken up but its quite a violent nose, it can be 'felt' through the crashbars mainstand, footpegs etc.

So I shrugged my shoulders and put it down to the rear shock.

Then I stripped the back down, pulled off the rear shock and checked the swingarm, perfect no sideways play, tiny bit up and down but not a lot (one of the linkage bolts looks slightly undersized, think this is normal). The swingarm moved very smoothly for the full extent of free movement.

no noise.

Great, so just to be sure I stripped the linkages, cleaned and greased all bearings (didn't remove the bearings though, they all looked pretty good with a fair amount of grease on them). Swingarm back on, and wait for the new Yacugar shock to arrive. Bike built back up having done the airbox mod to aid fitting the new shock.

With the bike built back up, the noise is evident again, shoulders shrugged and noise put down to knackered shock (thought the spring was turning against the collar and causing the noise).

New shock arrives and its a thing of great beauty. Fitted the shock and, noise still there, ****** !.

Strip the arm off again and double check the main swingarm pivot bearings, nope look good, nothing seen. Get a second opinion from another engineer (just to prove I wasn�t going mad) and no, visually as fitted they look fine.

Put back together, noise still apparent..... scratch head.

I thought it may be one of the other linkages however I found that if I loosened the swingarm pivot bolt a little, the noise stops. you can bounce the bike up and down, pull it over on the sidestand to fully unload the rear and its silent. Torque the bolt back up and .. crack, crack... crack crack.

Frame looks good, no cracks can be found.

If I turn the pivot bolt (not the nut) the entire pivot, bolt with it torqued up (I have a long breaker bar), I can cause the noise to happen. Nothing else moving at this stage, bike on mainstand, pivot bolt only turning. Noise evident when pivot nut torqued up, goes way then nut loosened.

So when the nuts torqued it must induce some sort of lateral compression which something is not happy with. I'll try turning in the little plastic adjuster tonight and see if that helps, but its too loud and violent a noise to be that.

So bearings now ordered, long, protracted tale of woe told.

All thoughts gratefully received, in 40 years of riding and maintaining my own bikes and cars, this one is one of the more annoying problems. Just hoping when I remove the bearings I'll see something that I can't see with them in situ.

Here's hoping ...................