Can I mix gearbox oils?

lori · Guest

Hi folks

I have a 1995 4x4 Leyland Daf ex-military general service truck which I've converted into an overland camper truck. It has a Cummins B-series engine.

At the moment I have 80W90 gearbox oil in the gearbox and diffs etc.

Currently I'm in Addis Ababa in Ethiopia and am finding it really difficult to find 80W90 oil to top up my levels. However, I can find 85W90 gearbox oil here.

Is 85W90 up to the task for my gearbox etc? Is it ok for me to mix the two, or will I have to either replace all the gearbox oil with 85W90 or somehow find 80W90?

Thanks
Steve
www.overafrica.org

RichardD · Posted: Thu Feb 04, 2010 11:58 am Post subject:

As long as both oils are GL4 or GL5 then there shouldn't be a problem. GL4 is an older specification whilst GL5 is newer and not appropriate for older gearboxes with (IIRC) brass bushings.

terence · Guest

Lori the gearbox oil in ethiopia will be spec for Africa

Ie its lower weight is higher to account for the higher ambient temps, and working temps.

mix away . Itll be fine.

i might suggest that upon return it would seem prudent to drain and re spec with the 80 W when you get back to the UK

it will be fine here too just less efficient. having moving parts in more viscous fluid at lower temps and all that .

lori · Guest

Thanks for the help guys!