Morris Minor Owners Club

Recently browsing the old posts (as you do) I came across the new-to-me info that all oil isn't equal. Apparently EP90 GL5 eats diffs.
Last year I came across a good deal on a gallon EP90 - just what I need for my back axle, thinks I, so diligently filled her up. Checking in my garage I now find that, of course, it is GL5. Dern!
What should I do? Drain the diff and refill? Ignore (it'll probably all leak out soon anyway)? Advice please - I don't do many miles in the Mog but I believe having a diff is useful even for the few I do.
Also filled up the steering rack with it - is this OK?
Ta for advice, Dave
PS. any offers for 7/8 gallon of good quality EP90?

All you can do is drain and refill really.
I'd be tempted to "flush" the rack with engine oil, no idea how aggressive GL5 is, I think it's brass that it "attacks".

Grease is so much better in the rack...........

Has anyone here actually seen any component - brass, bronze, whatever - that they believe has been attacked by the EP additives in a GL5 oil?

No-one in another messageboard I inhabit has, either - and there are some very experienced people there.

I spoke to Castrol Classic's technical person a few years ago about this, and was told that, while this may have been true many years ago, modern EP oils do not have the high levels of chlorine compounds that old ones did, and do not present any hazard, even to old gearboxes.

I tend to use GL4 oils in old transmissions, but only because they're sometimes cheaper, and do an adequate job when your diff is relatively lightly loaded. I wouldn't worry for one moment about any adverse effects of EP oils made in the last 25 years.

But I wouldn't use any old grease in a steering rack, either. If I couldn't stop it leaking any other way, I might resort to a semi-fluid grease, such as Penrite steering box lube.

Kevin

Racks in pretty much every car after the Minor (including the Mini with identical design rack) specify grease rather than oil, that just runs into the bellows and leaves the working parts effectively unlubricated.

MG Midget? Oil
MGB? Oil

If there's enough oil in the rack, the pumping action of the bellows will force oil back to the bearing, pinion teeth and damper; grease has no particular reason to return to those areas (if it ever gets there to start with) once it's squeezed out by the mating gears. Look at the what happens to needle roller bearings where there is insufficient angular movement to bring fresh grease to the needles, e.g. in prop-shafts which are nearly straight. Grease is fine for keeping muck out of bearings you can't seal properly.

I suspect that this one will join coils as an area on which we will have to agree to differ.

Kevin

Mini = grease (virtually the same rack - just a bit shorter)
TR7 = grease (virtually the same rack - just a bit longer) !

i have been using comma gl5 /ep90 in my diff for over 6 years no problems .

Well guys, a pretty diverse and interesting selection of replies. As always, variety is the spice of life I guess.
Many thanks for all the the info and views. I actually do feel much better about it than I did before and I think I'll leave all as it is at present. I have always reckoned that if knowledgeable people can't agree on something, then there often isn't a compelling argument one way of the other. But if all my diff teeth fall out sometime soon, I'll certainly report it.
Again many thanks,
Cheers, Dave