UJ bearing

Just been putting my 850GT loop back together having hopefully sorted the oil leak from the front of the bevel box. Just put the wheel back in and gave it a spin to check everything was free to turn etc. Unfortunately there seems to have developed a clicking noise, apparently from the UJ housing area, although could be rear of gearbox. Counted the clicks and there are 14 for each revolution of the wheel.

Any thoughts? I’m guessing UJ support bearing. Do these fail catastrophically - in other words I am OK to ride it to Mallory next weekend (approx. 150 miles) or do I need to order bits and fix it during the week?


About 1 per revolution of the shaft then. As far as I know weakest point is the needle roller bearings of the UJ, not the support bearing. Only one sure way to find out what’s going on, take swing arm off and have a look. I can see us just making guesses otherwise. Â Â

Thanks Mike - it will be coming apart, but would prefer to leave till after the weekend if it isn’t liable to seize and chuck me off.

I think bevel box ratio is 4.625 so 14 clicks per wheel revolution is about 3 times per driveshaft revolution I think?

Just a thought…
Does this happen on the stand or with the bike on its wheels and rolling along…or both?
It it’s when the bike is on its stand but not when it’s rolling then you’re OK.
The UJ can click when out of line. This also happens when overlength shocks are fitted.
Hoping Kate/Guy Wain happen along as they have a lot of expertise in this area. may be worth giving them a ring.
See you at Mallory

It’s on the main stand at the moment Steve. I did wonder about that myself, so I’ll disconnect the shocks tonight and lift up to ride height and see what happens.

UJ rather than support bearing though I’d change the lot (inc circlip), especially if UJ drops out of s/a when you take it orf! Parts same as later round barrels so easy to source. The one on my loop rumbled on for some time, and with no tell-tale vibration through footrest, as we were on hol at time! Even if it only happens on extreme of s/a travel it is still giving you notice - 'cos new ones don’t do it! If you want fitting tips, there are some archived on this site somewhere or give us a phone. If you have disassembly issues I do have access to a quite heavy duty (!) press!

For driving out the bearing I’ve used a 1/2" socket slightly larger than the inner race, on the end of a long  extension bar, insert into drive tunnel with UJ housing face down on block of wood, then apply  big 'ammer.

Remove its circlip first tho. :smiley:

Ride height doesn’t seem to make much difference. I think I’ll take it to Mallory this weekend and get it apart after that. UJ is expensive so I quite fancy rebuilding if possible. Will talk to Guy at weekend.

The support bearing is a standard item too and will be cheaper from a ‘bearing house’ than a Guzzi source. It may even be serviceable.
With a rebuilt UJ and possibly reusing the boot you can halve the cost of a kit.
See you Saturday

support bearing are available from your local bearing shop, but be aware that the bearing market now is awash with choice, some cheap and nasty some good, for example looking at the 'Simply Bearing ’ on line web shop they stock so many 6204 bearing (front wheel bearing for some Guzzies) that the prices range from around £3 to £150, the higher priced ones being for extreme temp use, I allways use the local bearing outlet and do state that the bearing are for motorcyle use so no cheap and nasty ones please.

+1 :bulb: