Possible UJ problem

[rologuzzi]

I have an '03 V11 Sport (Ballabio) which I've had for about 6 months & bought new. So far I've been delighted with most aspects of MG ownership, not least of which is the knowledge & good natured banter emanating from the owners forums.

 

I'm currently doing some preventative maintenance & preparation for an upcoming long ride. On removing the diff & driveshaft to lubricate the shaft coupling & UJ's (easier & more thorough than trying to get a grease gun onto the awkwardly placed grease nipples), I've found that the rear UJ is quite stiff & notchy when moved in one plane, & smooth when moved in the other. Could this indicate stuffed bearing(s) on the rear UJ, or is it possible for them to wear or settle at different rates? The front UJ seems to be OK in both planes. The bike has done 4000 careful km's from new & hasn't displayed any unusual noises or vibration that I can detect. It may be paranoia on my part but I'm reluctant to ignore this & reassemble hoping it will go away as I've read of nasty consequences of UJ failure.

 

Any info would be greatly appreciated.

 

Cheers

Tony

[Guest ratchethack]

Tony, I think y'er OK. I've noticed the same thing. When you rotate the joints past their normal range of operation, it feels like the bearings are rolling over hardened lumps of grease that accumulate in the bearing cups, since each bearing normally operates only back and forth within a narrow range of rotation. As long as the crosses feel tight in the yokes with no slop, and you've got fresh grease in there, y'er fine. NOTE: Don't forget to align the F/R trunnions via the white painted-on marks on the driveshaft when re-enaging the splines.

 

BTW - not that it makes any difference to ME, y'unnerstan' -- but a "differential" is found only on vehicles where power must be split to two driven wheels via planetary gears -- which Guzzi's ain't got. That's why on Guzzi's, The Oracle of Bungendore NSW (and certain other curmudgeons including meself) correctly refer to it as a bevel box.

[rologuzzi]

Rachet

 

Many thanks for your words of wisdom & comfort. The prospect of replacing the joints at such a low mileage is not appealing. The joint feels firm with no slop, just a difference between "feel" in one plane compared to the other. On rechecking the front, I now notice it too has a marked difference in feel, but again, is firm with no detectable slop.

 

Whilst I have good access to the joints & shaft, I'll pump some fresh grease into them, lube the splines & put it all back together. Re alignment of trunnions - paint mark is clear so it shouldn't be an issue - thanks.

 

BTW, is it easier to get the rear axle in & out with the bevel box torque rod disconnected, or is it just me? Seemed to be inordinately tight last time I did it with the rod connected. When I undid the rod from the bevel box, the axle could be moved much more easily. Could it have something to do with the "memory" of the rubber bushes when loaded (bike is resting on its wheels) compared to when they are unloaded (on the shop stand)?

 

I take your point about terminology WRT the bevel box & will refer to it as a diff no more!!

 

Cheers

Tony

[Guest ratchethack]

Tony, I'm not sure I understand this. You should always make sure to have the torque arm disconnected at the bevel box before attempting to take the spindle all the way out, so as to immediately withdraw the bevel drive, and not let it drop down and thereby stress the forward U-joint. When simply taking the wheel out to change a tire, I've found it most convenient to leave the torque arm connected to the bevel box, and leave the bevel box hanging on the spindle. In this case, I withdraw the spindle only far enough to get the wheel hub slid out of the female drive splines in the bevel box and withdraw the wheel. If you support the wheel and the 20 lbs. of the bevel box with one hand and jockey it around a little -- give it a little upward nudge or 2 -- you should be able to withdraw the spindle as far as needed fairly easily with the other hand. I always keep the spindle greased to protect from rust & to make this an easy operation.

[rologuzzi]

OK, thanks Ratchet. I think I now have it sussed.

 

Tony

[Guest ratchethack]

Outstanding. As they say south o' the border in Baja California, "Muy bueno!"

 

They also say, "Eeeeeholay!" but I got no clue wot that means. . . . . .

 

I reckon it might have somethin' to do with a popular extract of the ledgendary blue agave. . . . .

[belfastguzzi]

certain other curmudgeons including meself correctly refer to it as a bevel box.

certain other curmudgeons = Moto Guzzi

[docc]

I recall some needle bearings on the outboard side of the bevel box which would benefit from adding some grease while you have the access. Also, many have found their wheel bearings a bit dry. Some have carefully lifted the seals and added abit of grease to these as well.

[felix42o]

I haven't looked into this, as my white stripes are still in tact, but does anyone know if there are any other indicators with which to line the two halves of the Uni up, should the indicator lines somehow wear off?

[Guest ratchethack]

I haven't looked into this, as my white stripes are still in tact, but does anyone know if there are any other indicators with which to line the two halves of the Uni up, should the indicator lines somehow wear off?

Felix, without indicator marks, this can be done visually by aligning the planes of the U-joint trunnions. The yokes at each end of the shaft must be in the same plane to cancel-out sinusoidal oscillations in rotation. Properly aligned, the drive U-joint sets 'em up, and the driven one exactly nullifies the oscillation. Because the splines are relatively large, it should be pretty obvious if they're off by as much as one spline.

[Richard]

I haven't looked into this, as my white stripes are still in tact, but does anyone know if there are any other indicators with which to line the two halves of the Uni up, should the indicator lines somehow wear off?

 

Just to add to the illustrious ratchethack, when installed the UJ's should sit at exactly 90 degrees to each other as shown here -

[felix42o]

Ah, so that's the only issue then? Thanks for the clarification...I thought there might have been some other Guzzi Black Magic going on. Thanks all.

[belfastguzzi]

I haven't looked into this, as my white stripes are still in tact, but does anyone know if there are any other indicators with which to line the two halves of the Uni up, should the indicator lines somehow wear off?

The indicator lines will certainly wear off, but aren't there dimples? (Though visual alignment of the joints will always be the essential tell-tale.)

[rologuzzi]

docc, I know about the bearings of which you speak from my first wheel removal when the bike was new. I lubed them then & so far, they seem to be OK. Thanks.

 

The driveshaft on my bike, one of the later V11's to make it to Oz, has dimples (punch marks) which will provide guidance when the paint marks eventually wear off. In any event, ratchet & Richard's comments are all you need to correctly align the two halves of the shaft.

 

I've pumped plenty of fresh grease into the joints & they now feel smoother. Hopefully will be good for another year or so.

 

On a slightly different subject, I'd like to remove the fuel tank but I'm having trouble figuring out how to disconnect the fancy fuel line connectors from the tank. Is there a procedure described somewhere for this? I can't find any reference to the connectors in either the owners or factory shop manual, presumably because they weren't in use when the manuals were published.

 

Thanks

 

Tony

[Richard]

docc, I know about the bearings of which you speak from my first wheel removal when the bike was new. I lubed them then & so far, they seem to be OK. Thanks.

 

The driveshaft on my bike, one of the later V11's to make it to Oz, has dimples (punch marks) which will provide guidance when the paint marks eventually wear off. In any event, ratchet & Richard's comments are all you need to correctly align the two halves of the shaft.

 

I've pumped plenty of fresh grease into the joints & they now feel smoother. Hopefully will be good for another year or so.

 

On a slightly different subject, I'd like to remove the fuel tank but I'm having trouble figuring out how to disconnect the fancy fuel line connectors from the tank. Is there a procedure described somewhere for this? I can't find any reference to the connectors in either the owners or factory shop manual, presumably because they weren't in use when the manuals were published.

 

Thanks

 

Tony

 

They are self locking type connectors. To disconnect you have to force the fuel line towards the connection, while at the same time pulling back on the white surround, then pull away on the fuel line. It's a real pain of a job and takes some force and a lot of patience. I just wish that they kept the good old fashioned jubilee clip (did I really just say that.....?!?! )