Hello there!

So, the diffs are due to be delivered today. That means I will do some dirty, oily work quite soon. The rear axle oil question is easy to answer, the Detroit Truetrac needs EP90 (if memory serves well, will check the manual before buying).

As I need to go oil shopping anyway, I decided to do the gearbox as well, including transfer case.

Now, what oil should I use for a LT95? 20W50 engine oil as originally specced, or a GL4 80W90 gearbox oil for classic cars? No expert on the LT95, so besides avoiding modern oils that eat yellow metal I have no idea.

I'll leave the engine oil change to my mexhanic, that way he can install the new oil cooler and I void the mess the Rover V8 sump makes well removing the plug. The gearbox is much less difficult in that regard, as is the rear axle.

I've read that box has an internal oil pump, so i can imagine if you use an oil that's thicker than designed, the pump won't work so well and you'll have lube deficiency issues?

Don't know, never owned one

That's what I read as well... Not sure about it, as even LR itself is not using 20W50 anymore, for reasons. 20W50 it most likely is then, maybe I get a volume discount?