Gear Oil Type

Mobil 1 75W-90 LS (LS = limited slip)

 

Most transaxle oils have a limited slip additive. Some GL-5 oils, however, can harm brass synchro rings. Check the specs on the oil.

Incidentally, this is from the Mobil 1data sheet for the 75W-90 LS:

Not recommended for automatic, manual or semiautomatic transmissions...

So it is not recommended for our transaxles, just for hypoid gears.

 

This is a dumb question but - do all our cars have LS diffs as standard? I’m sometimes amazed about cars that don’t (911s for example).

 

Well... to be precise the Mobil 1 75W-90 LS Data Sheet says: "[...] Not recommended for automatic, manual or semiautomatic transmissions for which engine oil or automatic transmission fluids are recommended"

 

Stu- Yup, a quandary. There are transaxle oils out there that are GL5, but do not eat brass. Shell makes one. Nulon makes on too. The others, including the Valvoline I use, have warning not to use in manual transmissions. Slowly eats your synchro rings.

Darius- Affirmative, all our V12s have limited slip differentials.

 

Asgor- Yup, but it still eats synchro rings.

 

I admit I have lots to learn in this field (and many others) but... may I ask how/ why?

The Mobil 1 75W-90 LS Data Sheet specifically states: "Features: Excellent rust, staining and corrosion protection of copper and its alloys" - "Advantages and potential benefits: Helps to reduce wear; long component life".

Brass is a copper alloy, so what am I missing?

 

I would just go to my Ferrari dealer and get what they use.... Image Unavailable, Please Login
That is what I did
You will need the additive as well, which happens to be a GM additive...Yes you read that right! GM
I bought them both from Ferrari of Ontario...

 

Asgor- May work, then, but I would want one that says it is ok for transaxles.

 

Stu- Yup, the specs on the Shell oil above state it is designed for transaxles. Before they renamed it as one of the Shell Spirax family, the same oil was called Shell Transaxle Oil.

 

They sold me a Delco bottle and told me to put it all in!
Considering the fluids came from Ferrari, I am pretty sure they know what they are doing, and is followed up by this note from the Pennzoil web site:

SAE 75W-90, API GL-5 is the primary service fill rear axle oil for many passenger cars and trucks. SUVs and Trucks in particular may be equipped with limited slip differentials. Pennzoil Platinum® Axle 75W-90 contains sufficient limited slip friction modifier for many applications. Newer applications however may require an additional limited slip friction modifier. Pennzoil Platinum® Axle 75W-90 is fully compatible with additional friction modifiers.

 

it was a small bottle, estimated a cup worth.
Call your ferrari dealer ask them what they use!

 

Anytime!