Practically Classics Forum

I'm changing the oil in a 5 speed Type 9 gearbox (think Capri), but I can't find the right oil either.

The Haynes manual says on the 4 speed box to use hypoid gear oil SAE 80EP which is in my local factors no problem. For the 5 speed it says to use semi synthetic hypoid gear oil 75W/90S, not the EP. Problem is I can only source semi synthetic 75W/90 in EP variant.

Anyone care to explain what the difference is and why I can't use EP? From there any suggestions what oil to use would be appreciated?

Thanks in advance.

Sounds like time PC did an article on gear oils like the excellent one you did on engine oils a few months ago

I've got EP90 in my type 9. GL5 eats copper things, which is why it shouldn't go in some diffs (spitfires I think)

there should be no problem with the Extreme Pressure stuff, If a standard midget gearbox can survive on 20-50 engine oil then EP/non EP oil may not make a lot of difference.

When was EP invented - possibly after some manufacturers could spec. it?

Unless it categorically says don't use it (like for a spitfire diff), I'm pretty sure it would be OK.