Observation on Why MG Specifies 85W90 GL4 in the 6-Speed Gearbox

[Lannis]

Ok, as I realize when it comes to Guzzis I�m not the sharpest knife in the drawer. I�m nearing  the time to change the oil in my tranny and rear end in my 07 Calvin and was going to use a good quality 75-90 synthetic that says on the bottle for the 4and 5 types of oil. Am  I going to be ok?
These types of conversations are confusing for an old guy who has  ridden thousands of miles on all kinds of bikes and never changed anything but the oil.

Even the Guzzi manual specifies "..... or any quality oil meeting the specification."   The first recommendation is AGIP (now ENI), but even Guzzi says you don't have to use that brand.   Just meet the spec, is all.    I use AGIP because it's just as available and the same price as anything else, but there are 20 brands or more that will meet the spec.

Does it say "meets spec API SJ?"  Then use API SJ oil or a later spec (now SN).

Does it say "10W/60"?   Then use your favorite 10W/60.

Does it say "GL4"?   Then use GL4.

Does your brake fluid spec say "DOT3"?   Then use DOT3.

There are reasons why people fight against doing this and want to do something different, but the reasons are generally in people's heads, not for any practical, economic, or technical reason.   

Lannis

[Arizona Wayne]

Even the Guzzi manual specifies "..... or any quality oil meeting the specification."   The first recommendation is AGIP (now ENI), but even Guzzi says you don't have to use that brand.   Just meet the spec, is all.    I use AGIP because it's just as available and the same price as anything else, but there are 20 brands or more that will meet the spec.

Does it say "meets spec API SJ?"  Then use API SJ oil or a later spec (now SN).

Does it say "10W/60"?   Then use your favorite 10W/60.

Does it say "GL4"?   Then use GL4.

Does your brake fluid spec say "DOT3"?   Then use DOT3.

There are reasons why people fight against doing this and want to do something different, but the reasons are generally in people's heads, not for any practical, economic, or technical reason.   

Lannis

When I got my used `04 750 Breva it said to use 80W-90 oil in the tranny, so I did.  But I found that @ 40F temp. when I started riding the bike it wouldn't shift from 1st to 2nd properly until the oil warmed up some.  So I instead put 75W-90 oil in the tranny and all was well.      Some times you have to go against the recommendations when you find they are wrong for best results.

[Lannis]

When I got my used `04 750 Breva it said to use 80W-90 oil in the tranny, so I did.  But I found that @ 40F temp. when I started riding the bike it wouldn't shift from 1st to 2nd properly until the oil warmed up some.  So I instead put 75W-90 oil in the tranny and all was well.      Some times you have to go against the recommendations when you find they are wrong for best results.

Well, without a lot of experimentation (including possible DE), it's hard to get the big picture.   It might shift even easier with kerosene in the gearbox ... for a while.    Really hard to imagine that the difference between 75W and 80W would be noticeable, though.   As a lot of people have said, it's probably fine to use any modern multi-weight gear oil from 75W-140 to straight 90W.   

But I've never had any reason to experiment.

Lannis

[Arizona Wayne]

Well, without a lot of experimentation (including possible DE), it's hard to get the big picture.   It might shift even easier with kerosene in the gearbox ... for a while.    Really hard to imagine that the difference between 75W and 80W would be noticeable, though.   As a lot of people have said, it's probably fine to use any modern multi-weight gear oil from 75W-140 to straight 90W.   

But I've never had any reason to experiment.

Lannis

Lannis, in all the bikes I've ever owned this is the 1st bike that has acted this way.  I'm just glad the fix was so easy. 

[Kiwi Dave]

Even the Guzzi manual specifies "..... or any quality oil meeting the specification."   The first recommendation is AGIP (now ENI), but even Guzzi says you don't have to use that brand. 

My owner's manual (2017 V7-III Stone) states that the recommended oil manufacturer is now Castrol.




The Italians can sure be fickle.

[ITSec]

My owner's manual (2017 V7-III Stone) states that the recommended oil manufacturer is now Castrol.

The Italians can sure be fickle.

The announcement about the change in relationships was made a year or so back. Piaggio has had a very long relationship with AGIP/ENI, but Castrol has been pretty aggressive about courting manufacturers. Lube makers are always looking for ways to make customers 'sticky', since so many car owners are now just going with whatever their local drive through oil change place uses.

[Kiwi Dave]

Yep, and this is why I've never sought out AGIP/ENI.  Coincidentally, I've been using Castrol Edge 10W-60.  Foresight?

[Socalrob]

Souls...176 soles.
Is that the one where they had a runaway trim, and the pilot/s had to exert so much back pressure on the column that the nut stripped on the shagged threads on the jackscrew ?

Buddy of mine who is a pilot at Alaska Air (and was then) lays blame on the pilot.  They were flying level and straight (and not all that far from a super long runway at Vandenberg AF Base, but the pilot decided he needed to futz around with the controls to see what was what.  That's when it jammed, and in a bad position.  So I was told.

[Bonaventure]

My Stelvio owner's manual specifies "AGIP GEAR SAE 80 W 90" for the final drive/CARC and "AGIP GEAR MG/S SAE 85 W 90" for the gearbox.

When you buy these and look at the bottles, the gearbox oil says it's GL-4 and the CARC oil is GL-5.

Interesting as a theoretical exercise (which I think this is, as noted), but for me, who simply shortcuts all the oil mania by buying and using what the manufacturer specifies, it's a bit moot!

Lannis

The ENI sauces arrived today.  The 85W90 MG/S gearbox oil says GL-5 and the 80W90 CARC oil says GL-4. 

The ENI i-Ride PG 10w60 says API SG.  That indicates a content limit for Phosphorus @ 1000 ppm and ZDDP (Zinc) @ 1400ppm, per the API rules.  Those are healthy doses, I'm happy.  This oil should go the full 6250 mile service interval no problem. 

[Lannis]

The ENI sauces arrived today.  The 85W90 MG/S gearbox oil says GL-5 and the 80W90 CARC oil says GL-4. 

The ENI i-Ride PG 10w60 says API SG.  That indicates a content limit for Phosphorus @ 1000 ppm and ZDDP (Zinc) @ 1400ppm, per the API rules.  Those are healthy doses, I'm happy.  This oil should go the full 6250 mile service interval no problem.

Good for the bike and for peace of mind ....