Replacing Oil in the Rear Axle (Differential)
I have a 1991 420 SEL and want to replace the original factory differential oil.. I know what is specified for the car (Owner's Manual) but I have some fresh 85W140 Heavy Duty Hypoid gear oil (generic brand, not Mercedes). SHould I use it or get the stuff from the dealership???
Thanks in advance for any replies or suggestions....