Why the differences in V7 Transmission Maintenance?

[SmithSwede]

Factory manual says my 13 V7 Stone transmission oil should be changed every 6,000 miles or so.  It takes one liter.   

But I understand the newer 6 speed transmission has a much longer change interval for transmission oil, even though it uses considerably less oil. 

Is there a good explanation for this difference?

I've always wondered why Guzzi wants me to change the transmission oil so often.  I would have thought it would last much longer than that, provided you ride the bike regularly and it doesn't get contaminated with moisture from inactivity or short trips.  When I change the trans oil, it looks brand new.  (In contrast, the differential oil comes out nasty black, which suggests to me that the differential is tough on the small amount of oil it gets).   

So what's the deal?  Was the older maintenance standard far too conservative?  Something about the 6 speed that makes it gentler on the trans oil?   

[pyoungbl]

Take another look at the manual.  Mine (same year V7) says to change it at 600 and then every other oil change.  That would be at 12K, 28K, 37K miles.  Page 198.

Peter Y.

Why the difference between 5 speed and 6 speed...I think the bearings are different.  Pete Roper can chime in with a better answer.

[jackson]

My 2010 V7 manual says to change it every 7500 km (4660 miles). 
Is the gearbox in the 2013 different than the V7 Classic? 

[Kev m]

The maintenance intervals were all lengthened between the < 13 and 13 and later model years.

Why?

Well for starters I would guess the old intervals were just that, old, and had not been updated in quite a while.

Perhaps Piaggio finally has enough data to suggest a longer interval is no risk to their warranty liabilities.

Perhaps fluids have become better and better since the 4660 mile interval was first adopted on the smallblock.

Heck, our Ducati is 7500 miles with shared engine/transmission oil.

Most modern Harleys are 5k on the engine oil, but something like 15k or 20k on the primary and transmission oil.

So the 6k engine 12k trans/final drive hardly sounds like a stretch to me.

[SmithSwede]

pyoungbl.   You are correct sir.  Thanks.  Just cut my transmission oil expenses by 50%.

[sib]

First, lets agree on terminology.  Moto Guzzi uses the word "transmission" to refer to the rear, final, bevel drive, and "gearbox" to refer to what most of us would call the transmission.  Also, it is technically incorrect to call the final drive as a "differential", since it isn't one.

That said, the recommended change interval for the 6-sp gearbox oil is 1000 km and then 60,000 km, 120,000 km, etc.   Why so long?  First, the 6-sp box has an oil pump and an oil filter, and the 5-sp doesn't.  The filter will remove bigger, damaging bits better than a non-filtered oil flow. Second, the 6-sp box doesn't have needle bearings like the 5-sp box does.  These bearings are sensitive to tiny bits.  Third, the recommended eni (AGIP) Rotra 75W-90 oil for the 6-sp box has an additional API rating (in addition to GL4 and GL5) that the oil for the 5-sp box doesn't, MT1.  This spec is designed for extended change intervals, and also is supposed to lengthen the life of seals.  This oil is used in heavy duty truck gearboxes that go 500,000 km or more between oil changes.

But, really, how often do you change the oil in manual car transmissions?  I've driven many cars 150,000 miles or more, never had any gearbox problems, and have never changed the gearbox oil.

[SmithSwede]

Sib, thanks.   Exactly what I was looking for. 

Am I correct to infer that the 6 speed needs an oil pump because it runs on plain bearings, while the 5 speed gets adequate lubrication on needle bearings just from oil splashing and sloshing around?

[Kev m]

I didn't realize the design and related services changed dramatically on the new 6-sp Smallblock. Thanks for the lesson.

[Chuck in Indiana]

I didn't realize the design and related services changed dramatically on the new 6-sp Smallblock. Thanks for the lesson.

Get in the Game, son..It's been posted a few times.