gearbox problem

[guido]

I have just pulled the gearbox for failing to hold selected gears. Having hoped it would be just a spring problem, it turned out that a segment of a shifting ring fell out!!

These gearboxes seem to be very nice when they work, they shift better than the previous units (tonti framed), and they are considerably less noisy (clonky) than on the later units (Breva).

However they are fragile and dangerous.

Not one of Moto Guzzis better designs!!!

[docc]

Guido,

 

Was this one of the early units involved in the "recall?" And was the recall done?

[guido]

Guido,

 

Was this one of the early units involved in the "recall?" And was the recall done?

 

No it was not!

My original accident was with one of the recall items, but the box blocked because one of the gears fused (welded) to another, briefly selecting two gears at a downshift, blocking the wheel.

 

This unit is off no 015331 which is long after the re-call.

 

There is thus a good reason to be circumspect of the whole series, in my view.

 

Luckily this is the bottom left shift ring, which means that the loose quarter ring just fell to the bottom of the case.

Had it been one of the top ones, things might have turned out differently.

[docc]

Interesting. How many miles (kilometers) and what kind of oil in it?

[guido]

I can't tell you for sure, but the bike has 18000 km on it. I have done about 6000 of these, but it is propable that it could have done a bit more, most likely less than 20000km.

The gearbox oil I can't recall having changed, and it was full. It smells like a diff oil and looks tat way too. I would assume it is the required grade, as the bike was a unit from the local dealer, and was never sold before I acquired it.

The question is now how can I make sure that I will not have a third gearbox problem? Short of stopping using the bike?

[Paul Minnaert]

My box has done quite a lot km with my 1225cc 4v engine, no problems outside the spring.