gear box/differential oil

There was a lot of discussion about this on the Ferrarilist about a year ago.

A lot of people have had good results with Red Line 75W-90NS, which is for gearboxes. If you use an oil designed for limited slip diffs it is too slippery for your synchros to work properly and you will wear them out.

If you get too much noise or grabbing under hard acceleration in a tight turn with this you can add tiny amounts of limited slip additive until the grabbing stops.

Personally I find it works just fine without additive and the gearbox shifts smoother before it is fully warmed up.

Jim Oddie
246GT

 

Redline 75W90ns for the differential, Redline MTL (75/90) for the gearbox.

 

I assumed that you have a transaxle car. If you have separate gearbox and diff, you can use the different fluids.

 

I have had the absolutely best all-around results with Valvoline 85W140 gear oil. I've used it in differentials, transaxles, transmissions and steering boxes.
It works extremely well at all temperatures.
Using it in my 330GTC, 330 2+2, and my 308, it was always possible to shift from 1st to 2nd even when cold. I also use it in my FIAT and ALFA and I will soon put it in my 911.
When in the repair businees, I put it in all my customer cars unless instructed to do otherwise.

It is available from NAPA. 33 ounce bottle, Valvoline part #VV825.

Bob Z.

 

Shell produce a good oil for transaxles which they call "Spirax X 75w/90". I have used this in my 365 GTC and had excellent results. It seems to be as good for the gears as it is for the diff. Good luck!

 

It depends on your car and the age. Since your profile doesn't say what Ferrari you have and you didn't mention it then that leaves it wide open.

Synthetics have the best lubricating ability, but older cars do not have the same sealing technology as modern Ferraris and you can read posts on Ferrarichat.com where 30+ year old Ferraris will leak (seriously leak) if you use synthetics.