Just need some gearbox info

[Bajadera]

Well I have 2004 Breva 750 ie with 5-speed gearbox.
It has some strange noise(whining) when driving in 4th gear and in 3rd gear also but on 3rd not so loud.
I have changed the oil.
I didn't find anything strange in the oil.
Otherwise gear change is soo nice and smooth and the Breva goes really nice.
 I suppose that gearbox will need rebuild and I am considering to just replace the complete gearbox.

What other Guzzi models have the same gearbox like my Breva?
Nevada?
V7?
Any other model??
Thank you

[malik]

The Breva 750, Nevada & V7 (up to the V7 II - 2015 - six speed box - don't know if that one actually fits), & possibly the V65 & V75 are not significantly different. Whining is common on the smallblock, the gears are straight cut. It could be the hardening on the gear faces going, screeching is a sign that a bearing (or more than one) is going/gone. A decent low mileage box could well be a cheaper alternative, especially if you do the work yourself. Some of the gears are not cheap new, and the professionals are likely to charge a minimum of six hours labour just to get the gearbox out & back in again, before taking the gearbox apart and before replacement parts. While you are there, you might need to replace the clutch push rod oil seal & the clutch plate. Add in a couple more seals (the ones you can see) and there's another couple of hundred dollars.

[Bajadera]

So...
As I understand...V7 made until 2015 shoud also have the same gearbox as 2004 Breva??
That is good news.
And yes I will do the whole work by myself...that is not problem for me
I have been in old aircooled vws and vespas for a last 20 years

[Muzz]

There is a very good (and humorous) write-up by Nick Webb on This Old Tractor when four of us had gearbox problems.  Three had a generic fault which guzzi quietly fixed without telling anyone.  That is with the pre-selector fork, and you can only tell which model you have when you come to take the gear stack out, and especially when you go to put it back.

My 2003 had the later one fitted, some of your 2004 ones had the earlier one.  Go figure. <shrug>

In my case it is suspected that Luigi drilled the shafts off centre and 5th kept collapsing.  I got in a second hand one in from the States.

http://www.thisoldtractor.com/guzzitech.dk/pdf/gearbox-repair-breva-750-nick-webb.pdf

Enjoy.

[malik]

To remove the clutch shaft you will need a couple of special tools. I had the shaft holder made up from an old clutch centre, & the one to remove the nut, made from a 36mm socket.

The bend in the arms was custom fit to the bell housing.




I found the VW flywheel holder useful to get to the clutch - and you should have one of those.

[Muzz]

To remove the clutch shaft you will need a couple of special tools. I had the shaft holder made up from an old clutch centre, & the one to remove the nut, made from a 36mm socket.

The bend in the arms was custom fit to the bell housing.




I found the VW flywheel holder useful to get to the clutch - and you should have one of those.

Mal, your made-up tools are very similar to what I made up.


Bajadera, if you do decide to attack the internals of your gearbox, a couple of tips.

The crank you see in Mal's socket tool is vital.  I made up a spacer of the exact size, so when the spanner is put on the input nut it can actually be clamped firmly against the gearbox casing.  That nut is very thin, it burrs over easily and is an uncommon size.  To make the tool I actually bought a new 6 point Koken socket and cut the top of it and ground the bevel at the bottom of the socket off.  It really is a thin nut and the socket needs all the fit it can get.  The factory also do them up to about 6 million foot tons.  Clamp the socket and use the clutch centre tool to undo it.

[Bajadera]

Thank you all for a good advices about those special tools that I need for gearbox dismantling...
I think that I will try to source another good gearbox and just change it...
That is why I want to know what other Guzzi models have the same gearbox like 2004 Breva...

[Chuck in Indiana]

Before doing anything drastic, are you *sure* the sound isn't normal? Straight cut gears whine..

[Bajadera]

Well...
I can except the fact that the whine is normall...but why it is whining only in 4th and just slightly in 3rd gear?
1st,2nd and 5th are pretty quiet...
 

[malik]

Who knows? Just lucky I guess. There's a lot of different parts in there going around and around. Something would only have to be a fraction of a fraction off to produce noise. Other than my 5th with the disappearing hardening, I also have a whine in first, and some in fourth. And the faces of 1st & 4th looked to be fine when I had it apart. I sometimes notice the whines, but mostly I just don't hear them unless I'm looking for it. But then there's the 1100 Sport .... Now there's gear whine.