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Gearbox bearings


mjseymo

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Dear All,

 

I have a 2001 V11 sport here in the UK which has covered about 25K and is in generally good shape. However, recent difficulties with changing gear and the lever not returning has caused further investigation. Naturally return spring was the first port of call but all intact and fine as were the other springs and playing around with the detent setting made no difference. This only happened when the bike had done about 60km and up to tempreature. From cold there were no issues and a nice positive change in both directions.

 

So an experienced Guzzi mechanic and I ripped the whole thing apart to see what was going on. On first inspection the gears in mine seemed far better than most and no discernable play in the bearings. However, on closer inspection some of the inner tracks of the bearings have some rust and the edge of the hard chrome has pitted in a couple of places all of which have to be replaced. For some unknown reason that no one can explain these gearboxes boxes suffer from rust and iit s unusual to find one that doesn't have some no matter how often the oil changes or types of oil used.

 

We think the tolerances have changed enough when the bike is fully up to tempreature to cause enough movement and the problems associated with it. The setting of the detent position is very delicate at the best of times.

 

The box was never designed for 90hp either it being for a 750 which never went in production and the then the factory in their wisdom decided to lump it on the V11 rather than designing something specific for the bike. The straight cut gears are on only about 10mm wide.

 

So even a low mileage bike can suffer such difficulties. i would be interested to hear whether others have had their gearboxes apart and inspected them carefully for similar problems?

 

Cheers,

 

 

Martin

 

 

mini-Gbox 1.jpg  mini-gbox 6.jpg   mini-gbox 3.jpg  mini-gbox 4.jpg

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Martin, I did have the same problem with a V11 a few years ago, I think the gear lever occasionally used to stay in the down position until I released the clutch then it returned to where it should be, never did anything about it so can't help with a fix but it is a known fault

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  • 2 weeks later...
The box was never designed for 90hp either it being for a 750 which never went in production and the then the factory in their wisdom decided to lump it on the V11 rather than designing something specific for the bike. The straight cut gears are on only about 10mm wide.

 

Cheers,

Martin

 

 

  attachicon.gifmini-gbox 6.jpg   attachicon.gif 

Hiya, Martin! I'm curious about the source of this opinion of the V11 6speeder. I recall an interview with Dr. John (Wittner) about the gearbox developement in Greg Field's excellent book, Moto Guzzi Big Twins, but no mention (AIR) of this gearbox having been for a 750.

 

Also, since my hedgerows are quite overgrown, I'd so appreciate your sending your landscaper over for a romp. With the hedges of course . . . :whistle:

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If you follow my gearbox selector rework you wont have anymore issues with non returning gear lever or the "tap on the toe" issue.

It was posted a while back on wildguzzi and I posted the link here.

Ciao

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If you follow my gearbox selector rework you wont have anymore issues with non returning gear lever or the "tap on the toe" issue.

It was posted a while back on wildguzzi and I posted the link here.

Ciao

L'Phil: I'm not sure where that post and link are, but we should endeavor to archive it - like in the "How To . . ." sub-forum. :luigi:

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Here's the wildguzzi link. If I could re post it here I would, probably should have in the first place but I had a brain explosion.

If you're going to do nothing else do the shift lever arm lengthening mod. Its easy and very effective.

http://wildguzzi.com/forum/index.php?topic=80481.msg1275500#msg1275500

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If I remember correctly the too short hugger causes water off the rear wheel to soak the gearbox breather ?

That would certainly not help gearbox life if the oil wasn't changed often and/or the bike not used in hot /dry enough conditions to allow the moisture to vent out ?

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