I recently purchased a 2006 Moto Guzzi Griso 1100 (12,500 miles). Great looking bike and great to drive. However, on closer inspection there is a problem with the transmission and drive. There is too much ‘noise’ (rumble) coming from the Drive shaft area and possibly the gearbox. When stationary and the clutch is in, there is the usual dry clutch noise. When the clutch is let out, there is too much rumbling noise coming from the transmission and gearbox area. I have been advised that this is a definite problem and would require the Drive shaft to be disassembled and inspected for full diagnosis. Potentially it could be the UV joints on the each end, and worst-case-scenario, the CARC transmission.
Looking at the previous service I also noticed that AGIP 1740 85W140 transmission oil has been used, as opposed to the recommended 80/90 oil.
The questions I have are: -
a) Is the 85W140 oil likely to have caused this problem? (it has run 1000 miles on this)
b) Is this a problem anyone else has experienced? and if so, how did you deal with it?
c) Any other helpful comments would be welcome…
Many, many thanks in anticipation.
A small number of CARC Units have had issues with the Pinion Nut coming loose.
Not sure if it was only a certain year/batch that were affected.
Other than that, not heard of any major issues with the Drive-Train.
The Gearbox and CARC Unit are apparently ‘bulletproof’, as far as Pete Roper knows, and that’s good enough for me.
The reason for the slightly different Oil Specs between the Gearbox and CARC Unit is due to the type of metals used for one/some of the Bushes used internally.
I’d ask the question on the Griso Forum, if you haven’t already.
Doc. That’s great, thank you very much for your thoughts and advice.
I find it an odd problem, particularly given the low mileage.
To my way of thinking, if something like the Pinion Nut is going to come loose, it’s because of an ‘error’ on the production line, so it’s likely to manifest itself early on.
Also worth asking on the Adventure Rider Forum, on the Stelvio section.
No matter that it’s a Griso, the Drivetrain is identical.
Pete Roper’s a regular contributor on there, under the username Motomoda.
https://advrider.com/f/threads/moto-guzzi-stelvio-merged-threadfest.113158/page-2322
Doc, That’s great, many thanks.
I have also had a comprehensive response form Peter Roper off GrisoGhetto ( is he the guru of Griso’s?)
I have also put a video on YouTube. I was wondering what you think of how serious the problem sounds.
See;
https://www.youtube.com/watch?v=PDsMB6WOvm0&feature=youtu.be
https://www.youtube.com/watch?v=FL_Mlqjl_xw&feature=youtu.be
Not sure how far back Pete’s Guzzi experience goes, but as far as I’m concerned, he is THE expert on the CARC models.
Seems I misunderstood your initial post Marshy’.
I thought you meant that you thought the noise was coming from the Drive Shaft/Final Drive (CARC Unit).
At least we can rule out those two (expensive) parts!
Difficult to diagnose from a Video, but I’d say that’s not too noisy, for a Guzzi anyway.
If you don’t use earplugs while riding, I’d suggest you do.
I can’t ride my Stelvio without them, or I think it’s going to explode all the time.
Anything you can’t hear on a Guzzi with earplugs in, isn’t anything to worry about.
What was Pete’s verdict by the way?
Thank you for your reply. Very interesting particularly your comments on inherent rattles and noises. Maybe I’m being paranoid, but a Guzzi dealer said it needed inspecting. Hopefully the following link will show you Pete Ropers reply;
https://www.grisoghetto.com/t5336-2006-griso-1100-transmission-problem
A typically comprehensive Roper Reply!
Glad to see he got his favourite ‘Shaved Ape’ reference in there a couple of times. 
Like me, he thought you were saying the Final Drive might be noisy, as said, you can rule that out.