MT75 differential - oil change?

[jonb1985]

Hi all, thanks to this forum I've today established that I have an MT75 gearbox fitted to my 1991 Autosleeper Legend (based on a Transit mk3 petrol).

I've just ordered MT75 oil to give it an oil change.... But now I'm wondering if I ought to do the diff too - Would this be wise? 48000 miles on the clock and no history of a change previously.

If so which oil grade should I use - can I use the same MT75 oil? I got contradictory info from a google search.

Thanks in advance.

Jon

[Chug]

The diff doesn't have a drain plug so you will have to suck it out of the filler plug hole with a sump oil sucker, big syringe, or similar, the oil you want for the diff is EP 80-90.

[vanfox]

Does anyone ever change the diff oil? Maybe just top it up if needed. Why was a drain plug never fitted?
I guess some diffs are running on 20 yrs old oil?
If you want to change it I'd do it after a looong run when the oil is warm and thinner then suck it out.
EP 80-90 it is. Clean the crap away from the filler.

[Hondekop]

Does anyone ever change the diff oil?

Yes, I did. The oil may still be degraded by temperature, moisture, oxidation, grinding between the gears etc.. I doubt it will have the same wear and corrosion inhibiting properties it had originally.

I guess some diffs are running on 20 yrs old oil?

I think you're right.