u joint failure ...

[motospotter]

I am going through my 1978 1000SP today. It has 45,000 miles. I found metal bits in the swingarm, broken metal and needle bearings. The u joint was toast, and one of the caps had been damaged. I feel fortunate to have found it. I’m prepping for a 1200 mile ride next month.

[lucky phil]

You've dodged a bullet there.

Ciao

[moto-uno]

 Did you not notice a vibration getting progressively more noticeable when riding it ?  Peter

[motospotter]

You've dodged a bullet there.

I agree, it would have been a terrible April Fools ride ...

Did you not notice a vibration getting progressively more noticeable when riding it ?  Peter

This is the second time that this has happened to me. On my first SP I did notice it but I was not riding this bike a ton and it slipped passed me. The damage to this u joint was pretty bad, it was very loose. I just did not notice any vibrations.
They say you should start checking the U joint after 25k. This bike had 44k.

[Tom]

Look up John Chicoine.  He rebuilds and sells u-joints.

[sidecarnutz]

Phil is right. Dodged it well!

My last one to fail never did vibrate on me! My buddy and me tore our bikes down knowing it had been years since they were looked at. His was seized to the splines with fine dry rust. Coaxed it apart with a mallet, then cleaned and lubed the splines. His uni moved just fine. So his was OK. Mine? Splines were Ok but one cap of the uni was toast and coming apart. Rest were stiff. Quite loose. Yet on the trip to the WV Rally and back a couple months before it had felt fine. So I had lucked out. Guzzi's do seem inherently tough! I had one on my convert fail some years before and started crunching on my way home from work. I slowed way down and babied it and the pieces inside got me home. I spent the evening tearing it down and then calling Eish for parts. Thank God for Joe Eish! He had all the bits in stock and mailed them the next day for me. That was my go to work ride. Had to have it back!

[chuck peterson]

Pope’s blessing...bad things discovered at home. I’m telling you these horses have minds..

After a 2k, one week romp all over New England...

My torque converter spilt it guts the next weekend...one block from home.

Another 3day in VT, then 2 weeks later the ujoint ,
At home...how lucky can a guy get?

[John A]

Trained to break at home!
New sales pitch?

[motospotter]

Look up John Chicoine.  He rebuilds and sells u-joints.

The portion that connects to the tranny have these severe edges inside. I wonder if they could be machined smooth and be usable after. I should reach out to John. My problem is time right now. I will order from MG, early - spending ...

[huub]

rebuilding UJ is a pretty easy job , especially now the hard bit ( pulling it apart) is already done.
the bearings are around 10 euro each.
if you change the UJ , i would change the support bearing in the swingarm too, it probably had a hard time with the UJ wobbling around.

[n3303j]

I kind of "overfill" (+1 ouncr or so) my final drives. A certain amount of that oil heads forward around the forward spline and finds its way into the universal boot. Not a lot, but enough to work it's way into the needle bearings I guess.
75K miles on the T3 universal so far.
35K miles on the V11EV so far.

Old BMW /2 had no carrier bearing so its universal got a splash every hard stop. Had 50K miles on that universal when I sold the bike. Universal was still smooth.

[jwinwi]

Bought a 1990 LM1000 in 1996 and rode it home on the Slab about 85 miles at night. Got home around 11:00 PM and it wouldn't roll backwards into the garage. WTF?  Next morning tore it down and found the UJ completely destroyed.  At least one cap was gone so that cross was driving the yoke!  Didn't really notice the vibes because the bike was new to me. Still can't believe I made it home safely...

Motospotter: Based on the condition of yours, I'd just get a new one. MG Cycle sells 2 different grades of them. The old one doesn't owe you anything at this point...
EDIT: Might be worth it to replace the carrier bearing too...

[Antietam Classic Cycle]

My '69 Ambo has 111k miles on the original u-joint. I'll find out soon enough what condition it's in after all those miles.

[John A]

There’s been a few recommendations to replace the carrier bearing so I’ll add mine. A wise man once said: “if you are in there, replace it”. He had the most colorful turn of phrase but doesn’t post here anymore, sadly .

[motospotter]

On the one cap that was damaged there was plenty of oil, in fact all of the caps had plenty of oil on the needle bearing. I believe it was metal fatigue nevertheless new parts arriving probably Monday or Tuesday. I was taught to replace the bearing with the uni. Not sure who put that in my head but that’s rule ... I feel great to have found this before my ride.

[moto-uno]

  Good advice on the carrier bearing also.
Because I was never completely convinced that the swingarm retaining screws (although equal threads on each side) was truly centering
the swing-arm in relation to the trans output shaft , I turned a piece of steel tubing so the outside diameter was a snug sliding fit in the
U-joint bearing in the swing-arm and the other ends inside diameter was turned to be a snug sliding fir on the trans output shaft . This
pretty much guaranteed proper alignment and my last U joint has lasted literally 1 1/2 decades and many more kilometers than the previous
2 did . I also made the shock length and preload (with me on it) to keep the swing-arm as parallel to the road as possible . Not really that
much more work and you don't have to do it too often :) . Peter
The devil is in the details  .

[lucky phil]

  Good advice on the carrier bearing also.
Because I was never completely convinced that the swingarm retaining screws (although equal threads on each side) was truly centering
the swing-arm in relation to the trans output shaft , I turned a piece of steel tubing so the outside diameter was a snug sliding fit in the
U-joint bearing in the swing-arm and the other ends inside diameter was turned to be a snug sliding fir on the trans output shaft . This
pretty much guaranteed proper alignment and my last U joint has lasted literally 1 1/2 decades and many more kilometers than the previous
2 did . I also made the shock length and preload (with me on it) to keep the swing-arm as parallel to the road as possible . Not really that
much more work and you don't have to do it too often :) . Peter
The devil is in the details  .

If you want to know what the robustness of a Guzzi drive shaft is here's a quote from the Daytona shop manual.  "In the event of mainly sporting use or regular high speed travel replace every 15,000klm". Remember this is a brand that has always had major sales in Germany with it's Autobahns, so there's coverage for that type of use however a "get out of Jail" 15,000klm life span for a shaft drive system used in a sporting manner on a sports bike is a sign of the manufacturers faith in it's ultimate durability. Now I know there's a million people that will jump up and talk about the gazillion miles they have got from their shafts but the point remains even the manufacturer is concerned enough to make the shaft and joint life very conservative if their, at the time premium sports bike is ridden in a sporting manner.

Ciao         

[Antietam Classic Cycle]

Because I was never completely convinced that the swingarm retaining screws (although equal threads on each side) was truly centering
the swing-arm in relation to the trans output shaft , I turned a piece of steel tubing so the outside diameter was a snug sliding fit in the
U-joint bearing in the swing-arm and the other ends inside diameter was turned to be a snug sliding fir on the trans output shaft . This
pretty much guaranteed proper alignment and my last U joint has lasted literally 1 1/2 decades and many more kilometers than the previous
2 did .

So, how far was it off, did you have thread the pivot pin in much farther on one side than the other?

[motospotter]

If you want to know what the robustness of a Guzzi drive shaft is here's a quote from the Daytona shop manual.  "In the event of mainly sporting use or regular high speed travel replace every 15,000klm".   

of course the Daytona has an exposed drive shaft.

[Murray]

of course the Daytona has an exposed drive shaft.

Which you grease regularly and 100 000 miles latter and counting its still good (the splines wear out eventually).

[chuck peterson]

Bought a 1990 LM1000 in 1996 and rode it home on the Slab about 85 miles at night. Got home around 11:00 PM and it wouldn't roll backwards into the garage. WTF?  Next morning tore it down and found the UJ completely destroyed.  At least one cap was gone so that cross was driving the yoke!  Didn't really notice the vibes because the bike was new to me. Still can't believe I made it home safely...


See what I mean?..I’ve heard a ton of guzzi stories like this..

[chuck peterson]

Correct me of I’m wrong, but nobody’s mentioned pressing in the shaft to the bearing

Isn’t the unjoint/driveshaft to swingarm bearing an interference fit? I think you’re supposed to use a guzzi tool to press fit the two together. It keeps the driveshaft from spinning in the bearing. The trick is to keep the ujoint straight while doing it. No hammer blows either.

Anyone? I only did it once, but went to a machinist who understood the issue

[Tom]

U joints on the Daytona models (spiney) and install is different.  Haven't replaced any but I don't ride them where they get "hammered" on gear shifts.  The angle of the shaft is a determining factor because the whole drivetrain "floats".  The Tonti models are different.  I don't "hammer" either when I shift.  If anything, I put more stress on the clutch plate/plates on take-off.

[lucky phil]

of course the Daytona has an exposed drive shaft.

Like 99% of RWD cars that travel hundreds of thousands of miles on their uni joints.

Ciao

[Tom]

No boot around it or a shield to protect it like cars however.

[lucky phil]

The RWD cars I've e worked on had exposed tail shafts and no boots or covers just exposed uni joints. You're thinking of CV joints.

Ciao

[Tom]

Not thinking of cv joints.  Slip of the finger on the keyboard.  I was actually thinking of Moto Guzzi in general.  Main thing is the angle of the drive shaft from the u joint to the rear end.  More wear if the angle is too steep. 

[Tusayan]

The original Daytona drive shaft had no grease nipples, failed as a result and was recalled and replaced.  The 15,000 km recommendation was a result of that saga and IIRC was never removed from later versions of the service manual.  The later spine frame driveshafts were reliable - I’ve never personally seen one fail at any mileage.

[moto-uno]

  If my memory serves me , it was only a couple of turns off from original .
  To fit the U-joint into the carrier bearing in the swing-arm , I once again turned
  the outside of a piece of tubing to be an easy fit into the swing-arm housing and
  opened the inside diameter enough to keep the U-joint an easy sliding fit and
  that made it much easier to tap the chilled U-joint into the heated bearing ( think electric paint stripper gun).
It was worth the time !  Peter

[lucky phil]

The original Daytona drive shaft had no grease nipples, failed as a result and was recalled and replaced.  The 15,000 km recommendation was a result of that saga and IIRC was never removed from later versions of the service manual.  The later spine frame driveshafts were reliable - I’ve never personally seen one fail at any mileage.

I have, see the V11 forum.

Ciao