Lets have some fun: final drive oil??

[Anomaly]

Asking for a friend...

Guzzi manual says 85W140, while other sources (e.g., Cadre) show 75W90...

Thinking modern Guzzis, and E4 (E5 may be different?) models, what explains or is behind the discrepancy here?

[DoubleGuzzi]

There's no Anomaly, only confusion. 

Gearbox oil has been confused with rear drive oil.

[Anomaly]

Gearbox oil has been confused with rear drive oil.

Nope, it's not confusion. Some clearly call for/use the same in both the gearbox and the final drive....

[MikeP996]

 Ahh..the old "Asking for a friend" ploy.  I've used that myself a time or two!   

[Anomaly]

Ahh..the old "Asking for a friend" ploy.  I've used that myself a time or two!   

Shoot! You're on to me ...

Actually, I don't currently have a bike in my possession that this applies to, but wasting time on the internet can lead to some interesting questions....

[DoubleGuzzi]

Some clearly call for/use the same in both the gearbox and the final drive....

TBH, I betya good ol' fossil ATF and Hypoid 90 and would suffice, respectively. I'm not going to test the theory though. 

P.S. you missed the cringeworthy play on words in my first response

[Dirk_S]

Interesting. Can you upload a screenshot and tell us what models and years you’re seeing this discrepancy? Or at least share links to your source material. I too suspect you might be confusing the transmission with the final drive—which you may or may not know, has been listed in many a Guzzi manual as “transmission” (while the transmission is listed as “gearbox”).

[Anomaly]

P.S. you missed the cringeworthy play on words in my first response

I didn't miss it- since it was "cringeworthy", I simply ignored it...

[SIR REAL ED]

TBH, I betya good ol' fossil ATF and Hypoid 90 and would suffice, respectively. I'm not going to test the theory though. 

P.S. you missed the cringeworthy play on words in my first response

If I ever had twins, I would have named one Anormally and the other Anomaly.

[Anomaly]

Interesting. Can you upload a screenshot and tell us what models and years you’re seeing this discrepancy? Or at least share links to your source material. I too suspect you might be confusing the transmission with the final drive—which you may or may not know, has been listed in many a Guzzi manual as “transmission” (while the transmission is listed as “gearbox”).

Oh FFS! Really? I'm really not interested in throwing any particular establishment under the bus in an "oil thread" here. The original question was sincere and I know the difference between "gearbox' and "final drive" (and how Guzzi refers to the latter as "transmission"....

From the V9 owners manual:




And from the online shop of a well known and well respected (here on WG) dealer listing the contents of their 12,000 mile service kit:




Is that enough for you?

Could anybody comment on the merits of the two different oil weights suggested for the final drive, or should we continue to question my reading ability?

[Dirk_S]

Calm your pants and have a drink on me, amigo. It’s a very common mistake, and one that we English speakers (including you apparently :) ) know that the manufacturer could’ve done a better job of clarifying years ago.

[Anomaly]

Calm your pants and have a drink on me, amigo. It’s a very common mistake, and one that we English speakers (including you apparently :) ) know that the manufacturer could’ve done a better job of clarifying years ago.

Any comment (as related to the original question/topic) on the screen shots you requested?

[Tom H]

85w/140 is normally conventional oil. 75w/90 is normally synthetic. You can run either oil in both boxes. If I had a choice of the two and only could have one, I would go with the 85w/140 in both. But I'm more of a conventional oil guy.

When I help out at a shop, I put in what the factory manual calls for, but I normally would not use the recommended brand. If there is a problem due to the oil weight or Syn/Conv, we can say we used what the factory said, at least the weight and a name brand.

Tom

[faffi]

Asking for a friend...

Guzzi manual says 85W140, while other sources (e.g., Cadre) show 75W90...

Thinking modern Guzzis, and E4 (E5 may be different?) models, what explains or is behind the discrepancy here?

IIRC, the newer V7 850 calls for 85W140 in the gearbox and final drive, whereas my (now sold) V9 calls for the same gearbox oil and 85W90 in the final drive. When I replaced both oils recently, I just threw 85W140 in both, since final drives are pretty similar..

 I recently fitted the same oil to the final drive of my BT1100 Yamaha since I had something left, but was warned that it could be too thick. Since the final drive unit hardly ever reach the 40C temp of the lowest number listed (85W being measured at 40C, 140 at 100C), I cannot see this ever becoming an issue, but I replaced it with 75W90 simply because I learned how cool it runs in our climate and not having to listen to those who claimed the 85W140 was too thick.

[Huzo]

Shoot! You're on to me ...

Actually, I don't currently have a bike in my possession that this applies to, but wasting time on the internet can lead to some interesting questions....

Yes.
If you jump on the net and Google “lubrication for rear ends..”
You’ll not get the result you were (initially) seeking.

[Anomaly]

Yes.
If you jump on the net and Google “lubrication for rear ends..”
You’ll not get the result you were (initially) seeking.

You say that rather authoritatively. Not judging mind you...

[DoubleGuzzi]

I suggest that the use of the same grade in both G/B and final drive, is a cost-cutting/stock reduction ploy. Perhaps making the assumption that the rear "diff" can cope with a wider temperature range oil than is needed. For the sake of 130-180ml, it's a piddling amount when purchasing by the barrel.
Personally, I'd want the thinnest oil that meets the spec., to make rotational losses as least resistive as possible - shaft drive already is less efficient than chain, according to experts.
 

[Huzo]

You say that rather authoritatively. Not judging mind you...

I was…
“Asking for a friend…”

[Vagrant]

Be aware the 2017 V7III and I would assume the V9 got an internal oil pump in the 6 speed and a super fine oil filter so it then went to a 90#. 140 might be a big mistake.

[Anomaly]

Be aware the 2017 V7III and I would assume the V9 got an internal oil pump in the 6 speed and a super fine oil filter so it then went to a 90#. 140 might be a big mistake.

Yes, if you go back up- thread, the screenshot of the V9 manual specs 75W-90 for the gearbox.

[SIR REAL ED]

I was…
“Asking for a friend…”

How "close" of a friend were you asking for?   

[Huzo]

How "close" of a friend were you asking for?   

 

[faffi]

Yes, if you go back up- thread, the screenshot of the V9 manual specs 75W-90 for the gearbox.

Anybody know the difference between the V9 and for example the 2021 V7 850 when it comes to gearbox? The latter say 75W140 for both gearbox and final drive, the former only for the final drive. I deliberately put 75W140 in both the gearbox and final drive of my V9.

[Anomaly]

Anybody know the difference between the V9 and for example the 2021 V7 850 when it comes to gearbox? The latter say 75W140 for both gearbox and final drive, the former only for the final drive. I deliberately put 75W140 in both the gearbox and final drive of my V9.

Interesting -- the photo that accompanies the screenshot from the dealer I posted above indicates they are taking the opposite approach and using 75W-90 in both. I'm just curious what are te strategies behind these two different approaches? (as someone suggested above, the reason for using one oil in both places is probably a cost saving argument, but that still leaves te choice of which weight oil....).

[Dr. Enzo Toma]

FWIW, the owners manual and service manuals for both my 2022 V7 Stone (E5) and 2027 V7 Sport (E5+) call for:
"75W-140 lubricant for gearboxes and transmissions"

https://cadrecycle.com/product/moto-guzzi-v9-roamer-bobber-12000-mile-scheduled-maintenance-kit/
That Cadre listing shows a bottle of LiquiMoly 75W-90 while the part number 3603-0073 is for Motorex 75W-90. With that discrepancy on top of what you've already pointed out, I'd recommend just reaching out to them for clarification. Maybe they do recommend and use the same oil between gearbox and final drive, and can explain why.

[MikeP996]

Cadre may do it simply because they get a better deal on 75W90.     I would LIKE to think that Moto Guzzi knows best about what lubricant weight is appropriate for their components.   

OTOH, based on some experience with car transmissions over the years, 75/90 vs 75/140 probably won't make a substantial difference wear-wise in typical normal use. 

[DoubleGuzzi]

The thicker grade at higher temperatures might be solely down to reducing gear noise. Just saying.
 

[SIR REAL ED]

Cadre may do it simply because they get a better deal on 75W90.     I would LIKE to think that Moto Guzzi knows best about what lubricant weight is appropriate for their components.   

OTOH, based on some experience with car transmissions over the years, 75/90 vs 75/140 probably won't make a substantial difference wear-wise in typical normal use.

c

I would agree, it will make no difference during the life of the bike.  Although, the "correct oil" might extend gear life from 500,000 miles to 700,000 miles....  Which is a huge expense savings!!!   

This thread reminds me of the Aprilia RXV/SXV thread at AF1.  A half dozen guys there really knew how to make those bikes reliable.  They all had a common opinion of "never, ever trust any information Aprilia will give you on these bikes!  Aprilia may have made them, but Aprilia does not race them!"

If Moto Guzzi supplies confusing information, I would just follow the oil recommendations of BMW or any other manufacturer ( John Deere, Kenworth, Mack, Kubota, etc.).  No rocket science is involved here.

Oil opinions always make for some entertaining BSing!!  Great campfire fodder.

[Anomaly]

c

Oil opinions always make for some entertaining BSing!!  Great campfire fodder.

Precisely! Hence the title of this thread. You guys were a little slow in getting started, but you're doing nicely now...

(favorite line so far: "let's hope Moto Guzzi knows what they're doing"

[SIR REAL ED]

(favorite line so far: "let's hope Moto Guzzi knows what they're doing"

 

Which is a strange hope, given that most of the Moto Guzzi rider's expert opinions on this forum are precisely the opposite.....   

Paraphrased:  "Moto Guzzi's engineers/dealers/mechanics are idiots!  This is what the smart people are doing....."