Wheel bearing adjustment/shimming/set up
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Replacement wheel bearings are very rare and exceedingly expensive (How does USD $140.00 each sound?). Fortunately, the tapered roller bearings last forever if properly shimmed and greased. I pack mine with fresh grease every time I change a tire. If you've never repacked your bearings with grease, I highly recommend that you do so. Now. Likewise, the bearing free play should be checked and adjusted as well.
To set the bearing free play, the wheel must be off the bike and the seals must be removed so that you can feel resistance. I prefer to do this with cleaned and oiled bearings (rather than when packed with grease) because it is much easier to feel when things get too tight. A light coating of grease is okay. But if your bearings have age old hardened grease in them, forget about setting them until you thoroughly soak them in degreaser and clean them properly. I start by sliding the axle through, and then place a tube around the axle to take up the extra space between the bearing and the axle nut. I do this so I can tighten the axle nut down properly (factory spec is 101 to 107 pound feet of torque). Basically, you are securing the axle in place (as it would normally be in operation) and then feeling how the bearing is rotating. Then, you add and remove wafer-thin shimming washers between the bearings as needed. Generally I like to start with too many shimming washers. I'll remove them slowly until I feel the bearing get tight. Then I add a shimming washer back in and all is good. Hint, those shims really like to stick to the bearing's inner race when you pull out the bearing, so watch for that when you are removing the bearings and can't find any shims.