CARC Oil 85W140

Hi Guys,
I have just done an overhaul of my '08 GRiSO 8v, and between what the service manual says and the research done on the internet, I am still confused on the oil to be used in the CARC.
Here in France, ENI/Agip is a rare as hens teeth, so I had to buy the stuff from Germany.
The book states 85W90 for the CARC, but the German outfit sent me 85W140.
A bit of research on the webby came up with this :

eni Rotra bike MG  85W140 is a special EP lubricant complying with API GL-4 and API GL-5 performances, specifically designed for lubricating gears and final transmissions of motorbikes and scooters running under particularly heavy conditions and subjected to dynamic loads and high operating temperatures.
This oil has been designed with particular regard to lubrication of the spiral bevel gears of shaft transmissions on MOTO GUZZI models.

What do the experts think... should I swap out the 85W140, and fill up with 85W90 of leave the 85W140 in the CARC ?

Help appreciated.
Steve

You don't need to use the Agip stuff. Any quality lube of the correct or close weight will be fine. I use a 75/90 weight full synth made locally.

While the 85/140 will probably work OK frictional losses will be higher and in cold weather I'd worry about the pinion nose bearing being starved as it warmed up.

Pete

I use Motul 80W90, 'cos that's what my local Honda shop has.

beetle wrote:

I use Motul 80W90, 'cos that's what my local Honda shop has.

I use the same, 'cuz it's cool French stuff and the 10W60 smells all flowery and shit...

Quick question, what is the normal operating temperature of these CARCs?

Depends on conditions and how you're riding. How long is a piece of string?

Steak wrote:

beetle wrote:

I use Motul 80W90, 'cos that's what my local Honda shop has.

I use the same, 'cuz it's cool French stuff and the 10W60 smells all flowery and shit...

That's how we roll us French!

Actually the book says 80W90 for the CARC and 85W90 for the gear box.

There is a dude - called UBE - on the Italian Forum Animaguzzista.com who pretends that 85/140 grade oil is to be used on all C.A.R.C models. The guy is specialized in Guzzis and runs an independent Guzzi service garage in Mandello del Lario - he seems to be considered kind of a Guru on that forum.

On the older Guzzis what I heard is that using synthetic oil - as Pete Roper suggests it above - helps massively to eliminate clincks and clancks in the gearbox. I guess it can't harm the rear drive neither.

Tom
GRiSO 1100
T3 California

Ok checked the thread again and this UBE guy pretends that it is the MG factory itself that prescribes
the 75/140 or 80/140 or 85/140 graded and API GL5 specified oils for both the gear box and the final drive in all in-house communication material sent to dealers.

Gearbox prescribed quantity is 0,5 L but you can go up to 0,650 L
Final drive prescribed quantity os 0,380 but correct quantity is 0,350 L
(still according to Guru UBE - not on Animaguzzista.com as I remembered wrongly but on Grisoguzzi.it)

Need to read SAE J300/306 although for Winter grade (W) it's all based around correlations between lab viscometers and field experience mainly in main bearings and oil pick ups of big bus engines. 85W means the oil has a viscosity suitable for high shear cold starts at -12C. Any lower than -12C and the viscosity will increase and not lubricate or move as well - at some point it will also go solid as the wax crystallizes but that's bigger issue for oil sumps & pick ups (oil starvation) than gears which mash in the oil. The 85W also sets a minimum viscosity at 100C . The high temperature grade for gear oils eg 90 or 140 sets the max 100C viscosity suitable for normal operation once everything has warmed up(usually selected by OEM based on fuel consumption, emissions, frictional limits, etc).

So 85W's should behave same at low temperature, and you should consider picking lower W grade if you are spending lots of time at sub -15C to get lower viscosity at start & at normal (colder) operation - CARC/gearbox will run colder I guess in freezing weather.

For normal operation/summer grade, if Guzzi specs 90 I would stick with 90 unless I was using bike under conditions that will significantly raise the stress and heat in the oil eg high external temperatures, racing etc. Sticking 140 or higher will increase frictional drag which may affect operation and efficiency - it 'may' reduce wear but only worthwhile if wear is a weakness in the specific application.

Well I kept reading about the topic yesterday night on the Italian forum
and fact is that there is this noice about an in-house official communication about using GL5 rated 75/80/85-140 viscosity oil for both gear box and final drive. However, this piece of paper has not been seen by anyone - at least on the internet. Normally recall and similar in-house communications end up on the internet in forums like these but not this one.
Fact is also that there is nice confusion at the official Guzzi dealers. Some of them use 80/90 others 85/140 and others again use one for the gear box and the other one for the final drive.
Then another chap came up with some scientific explications pretending that the gear box needs GL4 rating whereas the final drive GL5 and that you should definitely avoid GL5 and the 140 oil in the gear box.
Well, it's a bit weird that the situation is not clear.
However I think as long as you are not racing not much bad can happen with a good synthtic 80/90.
At least in older Guzzis this has never been an issue.

I've recently switched to the Redline ShockProof stuff on the last service for both the GRiSO and the Stelvio.

[You must be registered and logged in to see this image.]
I opted for the Heavy ShockProof (the pink stuff) - Film thickness greater than an SAE 75W250, yet low fluid friction like 75W90.

[You must be registered and logged in to see this image.]
But the blue stuff might be worth a try too.  Lightweight ShockProof - Film thickness greater than an SAE 75W140, yet low fluid friction like 80W gear oil or 30W motor oil.

I use the same shit Roper uses, and my GRiSO goes like stink. 'Nuff said.





Word.

About the 85w140: Its used on small blocks, nevada and v7, don't know about v9... so its convinient for a service shop, to replace all others with this, just to avoid having to buy and stock varius quantities of stuf that may or may not sell. I do not trust the guy who says "the factory guys do not know, the stuf I have on my shelve is the same or better"

I know the head profesor at the oil and fuel lab of a univercity - the lab that does all the quality tests in Greece - he rides a Breva... This guy explained to me how to select oils. From all that he told me, my conclusion was, that i can safely use whatever i want for the motor as long as it is 10W60, but for the gearbox and carc, I realised that I'm not able to safely choose an alternative - even with the same viscocity. He was speaking not only about friction, but mostly about pressure and shearing, so I gave up, I'm not going to do a doctorate study for half a liter of oil, neither I'm going to risk my gearbox or carc, so I'm using exaclty what is specified by Guzzi...
gearbox: [You must be registered and logged in to see this link.]
carc: [You must be registered and logged in to see this link.]


About GL4 and 5: GL5 has better additives, can handle more pressure, but it corrodes copper and brass (maybe other metals too?). So, using GL5 instead of GL4 has a risk, who can be surre that there is no copper or brass to be corroded? On the other hand, using GL4 instead of GL5 has the risk of the oil not be able to withstand the forces that develops between the gears...

I'm sure, the Italians had a very seriοus reason to make the whatever effort needed to write this technical note : [You must be registered and logged in to see this link.]

Wow Avgpetro!
I think everybody on the Italian GRiSO forum is after this document (the last link in your text).
Much appreciated!
Cheers
Tom

AvgPetro

the oils that are in the service manual and that you cite too are both GL5.
These ones:
Transmission oil: ROTRA MP 80W-90
Gearbox oil: ROTRA MP/S 85W-90

Are you aware of that?

avgpetro wrote:

About the 85w140: Its used on small blocks, nevada and v7, don't know about v9... so its convinient for a service shop, to replace all others with this, just to avoid having to buy and stock varius quantities of stuf that may or may not sell. I do not trust the guy who says "the factory guys do not know, the stuf I have on my shelve is the same or better"

I know the head profesor at the oil and fuel lab of a univercity - the lab that does all the quality tests in Greece - he rides a Breva... This guy explained to me how to select oils. From all that he told me, my conclusion was, that i can safely use whatever i want for the motor as long as it is 10W60, but for the gearbox and carc, I realised that I'm not able to safely choose an alternative - even with the same viscocity. He was speaking not only about friction, but mostly about pressure and shearing, so I gave up, I'm not going to do a doctorate study for half a liter of oil, neither I'm going to risk my gearbox or carc, so I'm using exaclty what is specified by Guzzi...
gearbox: [You must be registered and logged in to see this link.]
carc: [You must be registered and logged in to see this link.]


About GL4 and 5: GL5 has better additives, can handle more pressure, but it corrodes copper and brass (maybe other metals too?). So, using GL5 instead of GL4 has a risk, who can be surre that there is no copper or brass to be corroded? On the other hand, using GL4 instead of GL5 has the risk of the oil not be able to withstand the forces that develops between the gears...

I'm sure, the Italians had a very seriοus reason to make the whatever effort needed to write this technical note : [You must be registered and logged in to see this link.]

tjo wrote:

the oils that are in the service manual and that you cite too are both GL5.

Correct, mentioning GL4 was not only off-topic but off-forum, as it is obviously wrong to use it for GRiSO. It was a generic note for people that have bikes that are made for GL4 - using GL5 might be risky...

Petros

PS: the first link i previously posted is "ENI ROTRA BIKE MG/S 85W-90". Its a newer product of ENI, "MG" stands for designed specifically for Guzzi gearboxes - and aprooved by Guzzi.
Datasheet: [You must be registered and logged in to see this link.]

Anyone used olive oil yet?
It's Italian...

Petros

It's interesting what you say about GL5 and GL4. I thought there is not much difference between the two and that GL4 would not damage a gear box that officially requires GL5 as long as viscosity is the same.

On the italian GRiSO forum there was a guy posting that the C.A.R.C. Guzzis definitely need GL4 in the gear box but GL5 in the cardan.

But since the two different oils prescribed buy Guzzi are both GL5 I guess you are right and it needs GL5.

What do you think about people (and dealers) putting the 80W90 in both places and not bothering with two different oils? Are they causing trouble?

Tom

avgpetro wrote:

tjo wrote:

the oils that are in the service manual and that you cite too are both GL5.

Correct, mentioning GL4 was not only off-topic but off-forum, as it is obviously wrong to use it for GRiSO. It was a generic note for people that have bikes that are made for GL4 - using GL5 might be risky...

Petros

PS: the first link i previously posted is "ENI ROTRA BIKE MG/S 85W-90". Its a newer product of ENI, "MG" stands for designed specifically for Guzzi gearboxes - and aprooved by Guzzi.
Datasheet: [You must be registered and logged in to see this link.]

tjo wrote:

What do you think about people (and dealers) putting the 80W90 in both places and not bothering with two different oils? Are they causing trouble?

About people, I don't think anything, everyone can do what he wants with his bike (exept messing with other people), for whatever reason, its his property, money comes out from his wallet...
About dealers, I can't document that they're cousing trouble, still as i wrote before, I don't trust the salesman who tries to sell to me not exactly what I want, but exactly what he has. On the other hand I trust the university chemistry professor specialized in oils and fuels, who's also a Guzzista...
Think about this: Using 80w90 for both gearbox and carc, would be more cost effisient for Guzzi fatcory also - for their purchase department, warehouse, production... Would be easier for all. Cost efficient and EASIER, and the Italians do not do it? Surely, there must be a very good reason.

Merry Christmas to all

Petros

Oh there probably is a reason. Some sort of engineering pedantry would be my guess. Look guys, it's a gearbox, there is nothing magical about it, it isn't held together by fairy-dust and protected by magic.

Compared to something like a truck gearbox what the oil is asked to do is a walk in the park, really.

The six speed box used in our bikes has mainly sealed 2RS bearings in it so lubrication for them is almost a non issue. The pinions themselves? There are only going to be the primaries and one secondary carrying load at any one time, the rest are freewheeling. The oil doesn't have to work very hard.

If anything the oil spec may be chosen for longevity, perhaps as a fail-safe in case people neglect their oil changes, but really any decent quality synthetic gear oil of approximately the correct viscosity will provide all the protection you need in both the gearbox and the bevelbox where both the bearings and tooth area of the crownwheel and pinion are HUGE! Massively disproportionate to the loadings they are expected to carry.

By all means obsess about this if you wish but as I said earlier the only reason I'd advise against an 85/140 in the bevelbox is that when cold it might starve the pinion nose bearing.

Look at it this way. In the ten years the six speed and CARC have been in production I've been inside quite a few CARCs to replace seals and, with the early ones, replace bearings due to the factory bean counters buying cheap. Apart from those early bearings the only failures I've seen have been down to the pinion nut loosing it's preload and that has nothing to do with oil!

As for the six speed box? I've yet to have to have one apart due to mechanical failure! I took an early one off a B11 apart just out of interest but apart from that they just keep going. I can assure you that not all of them run the *Exact* specified oil in them!

Ride more! Worry less!

"ride more, worry less '
I like the sound of that ...........

Interestingly Pete, Guzzi's recommanded gear and cardan oils are not even synthetic according to their specifications. I know the old Guzzis were very indifferent to the type of oils they received (as long as they received any and had been changed within a reasonable miles-frame); am happy to hear from you now that it should be the same with the C.A.R.C. models.

However Pete, it seems that regarding engine oil there is a relative anonimity that 10W60 shall be used. In my old LeMans and T3 it was absolutely no issue to put 20W50 (as long as you don't ride in Siberia in Winter) or the most common 10W40.

Tom

The viscosity is less important than its heat resistance before it degrades.

Happy Christmas. Fuck oil threads.