EP80/90 and 20w50 mineral - will it mix?

[Mark Serj]

Guys,

I have either EP80 or 90 in my MOD gearbox at present and it was recently changed. However due to an oil leak through the clutch bearing extension nose fasteners it needs topping up. I like what I hear about using mineral 20W50 in the box, but right now I just have other priorities so haven't the time to drain and re-fill completely. Anyone know if topping up with 20w50 mineral would be a problem please?

Thanks in advance as always

[DJT]

Surely using 20W50 will only make the leak worse as it is thinner than the EP80/90.....

FWIW, I never felt the need to change to a lower viscosity oil in the MOD box on my previous Stag, which was driven all year round for over 60,000 miles during my ownership.

[marshman]

Surely using 20W50 will only make the leak worse as it is thinner than the EP80/90.....

FWIW, I never felt the need to change to a lower viscosity oil in the MOD box on my previous Stag, which was driven all year round for over 60,000 miles during my ownership.

The viscosity of gear oils is rated/quoted/measured differently to engine oil. There is little difference in the viscosity of ep80/90 gear oil and 20w50 engine oil.

Mark, unless the level is so low the overdrive will not engage I would leave it until you can do a complete drain and refill rather than mix 2 different types of oil.

Roger

[Mark Serj]

OK thanks Guys, sound advice.