Quick update,
Got the car home safely. just a little bit of a whine on the Gotthard pass, no chattering. Much cooler weather and rain might have helped keeping the temp of the diff lower. I drained the oil from the diff and it looked pretty 2nd hand almost black. I looked for castrol SAF XJ but that seems to be an older spec. no longer on sale here and not on the Castrol website. On the Castrol site they now have Transmax Axle Limited slip 75W140 for this purpose. I confirmed with the Morgan dealer/importer here that this is what they use. So I bought this but I am still not sure if I should add a friction modifier to this oil. On the filler of the diff there is a plate (as a washer with a tab) with the text; "use approved oil & friction modifier" But is this friction modifier already in this latest Castrol oil? No reference to it on the product data sheet. It does say "It is approved for use in the high performance BMW-M Series and Mercedes Benz AMG limited slip differentials." "Approved - MB-Approval 235.61, ZFTE-ML 05C, ZFTE-ML 16G, ZFTE-ML 18, ZFTE-ML 21C BMW LS Rear Axles"
My guess is it will be OK but I thought I would ask here. Btw I also asked Castrol by mail, no reply yet. I will update here when I get an answer. (I think I know what it will be ;-)
Regards, JJW
Last edited by JJW; 28/10/23 09:50 AM.
