rear wheel bearing bugaboo

[vtv11lemans]

After 3-1/2 seasons of virtually trouble free riding on my '02 LeMans, left side (circlip side)rear wheel bearing fragged on me after a 2600 mile trip to NC (Blue Ridge area) and back to Vt., with 28000 mi. on odometer. Had to ride it for about 150 miles on the bad bearing (no choice-no dealer would touch it). I managed to gingerly wobble it home. I had just replaced tires (before trip) on front/rear and torqued the rear axle to about 100-110 ft/lbs. I later found out it was supposed to be 88 ft/lbs. Could this have led to early demise. I've read the about how critical the inner spacer dimensions are. Though when I inspected the spacer face that rides against the inside of left bearing, it didn't look unusually worn (I could see it because the bearing inner race virtually fell out after wheel removal). I subsequently took wheel to Guzzi dealer in NH. I requested he inspect the inners of the hub to make sure I didn't do further damage by riding it. Also mentioned to him about how critical the inner spacer dimensions are. He didn't seem to be overly concerned about that nor the over torqueing I had performed. To his defense, he couldn't recollect doing any bearing changes on either V11 Sports or Lemans's. He subsequently replaced both bearings (left and right) manufactured in France (stock were Italian I believe). This time I was a little conservative and torqued it to 80 ft/lbs. Within 700 miles the same bearing failed and far more immediately, within 50-60 miles of the first sign of trouble (grease weeping out at the inner diameter of grease seal-where it mates with caliper spacer). Then came the ugly clunking noise and next thing I know, I'm wobbling again. Fortunatley only rode it for about 10 miles. What's your thoughts on this and what should I stress to the mechanic. Am I looking at replacing the whole hub or just a new spacer. The ouside right bearing looked fine. Thanks. Leon

[Guest ratchethack]

That's a sad tale, Leon. IMHO you've had the infamous "shortened" spacer syndrome, likely brought about just as you suspect. The way to know for sure is to get an accurate measure on the spacer against the dimension between bearing registers in the hub. You want the spacer (as I recall) .006-.008" longer than the space between registers. As far as the liklihood of needing a new hub, any good machinst could tell you this with an inspection. Not to make you feel any worse after the fact, but it probably should've been trucked from the point of original bearing dintegration, even at considerable inconvenience and/or cost. The spacers are of inferior grade and y'er next one'll undoubtedly be a coupla notches harder and beefier. Don't know about any possible up-train effects on the crownwheel and pinion, but this'd be the high dollar item at risk here, and I'd sure have 'em carefully checked. If Pete sees y'er post, he'll be sure to give you the correct read on it.

 

Good luck, my friend.

[Wick]

Sounds like your spacer isn't up to spec.

 

Wick

[Baldini]

I had pretty much same experience. L side brng went, then replacement went immediately after I fitted it. Checked spacer - too short. Made new heavier spacer to correct length - no more problems. My guess is that crap MG spacers though possibly of correct length are compacting under load of (over?) torqued axle nut. Interestingly the manual gives a torque setting measured at axle head....

 

KB

[Guest Mr Eko]

YOu mean this spacer pointed by the arrow?

 

 

 

I found at 23.000 km both rear wheel bearing broken. The right one (cardan side) was completely destroyed (ballcage broken), and the left one ran harldy.

 

I replaced both with the best bearings (skf of fag). At the cost of 4 euro each.

 

So i think i'm gonna replace them every tyre change, just to stay to the reason side.

 

btw...

 

I can't understand everything you say....

then i ask:

 

the bearing are gone because of the short spacer?

 

so overtightening rear axle nut make work incorrectly the bearings?

[tikkanen]

Hi Leon,

 

Orson have just been visiting me on his Tour de Europe. On his way through Norway his rearwheel's bearing went south and he had to have it replaced up in Oslo. Orson's Tenni has just 50.000 km (30.000 miles) on the clock.

 

Furthermore his rear tyre looked like shite when I met him at the ferry in Denmark. It was just like there was a deep cut on the left hand side of the tyre. Naurally Orson had his tyre replaced here in Copenhagen but nonetheless it sounds strange that a tyre can be worn so badly.

 

To cut a long story short you're not the only one having problems with your bearings. In fact Orson's Tenni has been visiting the mechanic three times to have rearwheel bearings replaced.....

 

Ciao

 

Søren

[Martin Barrett]

That yellow thing is the beastie. I was destroying bearings at the following milages

6,000

18,000

23,000

24,500 I then shimmed out the spacer with a washer (ala BFG) and it seems to have done the trick I,m now at 26,300 and seems to be fine*. I've a new spacer on order.

 

I was going to go down replace the tyre change the bearing route but they started collapsing before I got round to the replace the tyre.

 

 

* It might have caused the wheel to centre slightly different in the frame. I'm sure the UJs look after the bevel box, and the brake pistons should also do so. But I did have to stand the rear end up on beer crates to inspect a strange noise 500miles in having got to the German Treffen. Couldn't identify it but thought it might have been from the rear pads. But seemed all okay, only recently changed and cleaned. And it never repeated itself.

[Baldini]

....so overtightening rear axle nut make work incorrectly the bearings?...

 

I can't understand me either....

 

When the rear axle is tightened, the load is taken through the bearing inner races via the spacer (shown in yellow in your pic). If you were to overtighten the axle nut the spacer may compact (shorten) thereby pushing the bearing inner races out of line with their outers (which are hard up against the hub shoulder). This will quickly destroy a bearing.

 

When I measured my spacer it was shorter than the distance measured between the bearing housings. This may have been a manufacturing fault, but IMV it is more more likely that I overtightened the axle & compacted the spacer.

 

As I understand it, wheel bearings designated "C3" should be fitted. C3 indicates some additional clearance to allow for some movement of inner race relative to outer.

 

Another point worth attention is that new bearings should be drifted home bearing on both inner & outer races (using a flat drift across BOTH faces) to ensure central spacer does not cause inner/outers to become misaligned.

 

KB

[Guest Mr Eko]

clear

thanks