2020 V85TT Rear Transmission Leaking

[timonbik]

Recently completed a 1000 mile trip on my 2020 V85TT with 53,000km on the clock.  Rode 500 miles to my destination and upon arrival there was no sign of any leaking.  Bike sat overnight and in the morning I observed a small dribble of gear lube on the rear rim.  it was leaking from the space between the rear wheel and the bevel drive.  Rode around town a bit and there was minimal leakage but it was still leaking.  Hit the road to travel home and it appeared to be good after an hour but after 2 hours it was definitely leaking again.  At about 250 miles the wheel was oil soaked. I know the drive was not overfilled as I personally filled it myself and used a syringe to add the requisite 160ml of gear lube and the bike had travelled  in excess of 15,000 in on that fill with no sign of leakage until this trip.  The parts diagram shows multiple seals, o rings and gaskets internally.  Any suggestion as to where to look first.  It is NOT leaking from the pinion/input seal. 
Thanks, Tim

[guzzisteve]

There is a thread on here just recently about same thing, only adding 130cc, look around you'll see it


Here---------------

https://wildguzzi.com/forum/index.php?topic=125639.0

[timonbik]

If one follows Guzzi's line of thinking why put any lube in at all that way there would be no chance of leakage.  The designers/engineers originally called for 180 ml, then it was reduced to 160 now  130.  Something's rotten in Denmark me thinks

[yrunvs]

If one follows Guzzi's line of thinking why put any lube in at all that way there would be no chance of leakage.  The designers/engineers originally called for 180 ml, then it was reduced to 160 now  130.  Something's rotten in Denmark me thinks

It is a little bit of a mystery as to the correct amount of oil for the pre E5+ model v85tt's. The E5+ manual states to refill with 130cc but I can find nowhere this amount for the E5 everything I find states 160cc's is the revised amount from180cc. There is a possibility that the final drives are different in some way???

[Dr. Enzo Toma]

I suspect that there could just be more "residual" left over after draining a unit that was filled to 180cc when assembled.

I had a similar issue with my V7 850 and for mine. Filled to 160cc, it leaked from the spot you describe. Filled to 130cc, no leak. Knock on wood.
https://wildguzzi.com/forum/index.php?topic=123836.0

[SIR REAL ED]

If one follows Guzzi's line of thinking why put any lube in at all that way there would be no chance of leakage.  The designers/engineers originally called for 180 ml, then it was reduced to 160 now  130.  Something's rotten in Denmark me thinks

The difference between the recommended oil volumes could be as simple as a typo in the original specified amount.  Followed by another change because there is some residual oil that does not drain.  Never underestimate the human capacity for miscommunication.

If you reduce the volume of oil, and the leaking stops, I would say "Problem solved!"

[Vagrant]

With that many miles on it the odds are the seal or vent has failed. Checking the vent is free and complete draining and refilling with 130cc is basically free also. It's worth a try.

[SIR REAL ED]

The difference between the recommended oil volumes could be as simple as a typo in the original specified amount.  Followed by another change because there is some residual oil that does not drain.  Never underestimate the human capacity for miscommunication.

If you reduce the volume of oil, and the leaking stops, I would say "Problem solved!"

I just noticed.... 8, 6, & 3 look remarkably similar don't they?  I'd bet money misreading or poor transcribing is a factor.

[JHBettsSr]

It is a little bit of a mystery as to the correct amount of oil for the pre E5+ model v85tt's. The E5+ manual states to refill with 130cc but I can find nowhere this amount for the E5 everything I find states 160cc's is the revised amount from180cc. There is a possibility that the final drives are different in some way???

Good question. According to the AF1 OEM parts catalog the "Transmission Complete" part number did change with the E5+.
E4 Early 2B0042715
E4 Late  2B0068275
E5   2B0068275
E5+ 2B013050

[Dr. Enzo Toma]

If you check the individual part changes, you may find that the breather and some other parts were revised as was the case for the V7, but I doubt the physical volume the pumpkin can hold changed - just the spec when Piaggio got enough reports that 160cc was causing it to leak. I recently had my V7 850 in for service and they changed the final drive oil without it having been on the maintenance schedule... talked with them and learned that the spec they have is still 160cc even downloading the PDF manual right then from Piaggio/Moto Guzzi to check it for any updates. So to my knowledge, it was overfilled, but to all available documentation to them, 160cc is still the spec and no TSB is issued to say otherwise.

I would have drained and filled it again but had to hit the road and figured I'd let it leak if it's going to leak, at the point the final drive leaking on my V7 is like a Harley leaking oil, you become worried when it doesn't. Around town and interstate - no problem. Then earlier today I rode Spearfish Canyon in SD and next gas stop it had leaked all over the rear wheel again. Wiped it down, rode mostly straight and interstate roads after that, no more leak. My impression is that the canyon riding had some influence on the leak since it otherwise hadn't lost oil. Maybe something to do with sustained lean angle? Just a guess. Anyway, now I am back home and have some time. I plan to drain and fill to 130cc, and install the plug marked 130cc max before the Colorado Moto Guzzi rally in Hotchkiss later this month so it's not oiling the rear tire again in the mountains.

[Vagrant]

It's not the lean angle. If it were all of mine would leak. JMHO bit it says 130 MAX! If I was having your issues I'd do 120 and maybe switch brands of oil.