By popular request (i.e., spouse) - I have disposed of all Brit cars other than my 1962 Mk2. Now to clear out 30 years of assorted supplies. I have two quarts of Castrol Hypoy 80W-90 GL4 oil and two quarts of Brad Penn 213 80W90 (apparently got them from the Roadster Factory for my TR6). I cannot use them in the Mk2 transmission (Moss non-synchro SAE 30) but will they be a lifetime supply of oil for the rear differential?
george leicht
Cincinnati OH
65 Mk 2
Warm 80W90 gear oil has viscosity just a bit more than 30W engine oil and often is used in manual transmissions. 30W is a bit easier to pour when cold and widely available. I’ve used 80W90 in Moss boxes just fine. 90 is common standard for rear axles.
80W-90 is fine for differential.
There was a Jaguar Service Bulletin, not numbered but dated 16 Sept 1957, that said specifically NOT to use other oils in Jaguar manual gearboxes and overdrives, but to use only SAE 30, warning that mechanical difficulties or failure could result from incorrect oils.
They meant the synchronizers would not work right with oil of the wrong viscosity.
5W-30 or 10W-30 which didn’t exist at that time are also fine. The W numbers simply refer to the Winter viscosity range, and the 30 is the summer viscosity range.
Thank you both. Looks like I have lifetime supply of rear axle lubricant!
george