gearbox oil

im going to service my 200 tdi soon and read that the manual gearbox uses ATF but i been told its best to use normal gearbox oil instead as its better for higher mileage gearboxes , im confused now so wots the best to use from your own experiences ? thanks

It is a common mistake to think that it must be better to use a thicker heavier grade of oil. I mean, it's OBVIOUS, innit? That's why a number-one cause of gearbox and engine failure is nutters using gear oil like EP90 in engines, and in gearboxes that specify auto trans fluids.

In a gearbox asking for auto-trans oil, you MIGHT get away with tractor universal 10W-30, but I would only try it in emergency, meaning it was the only oil to hand, and would be a whole lot better than no oil. I would drain it out smartish when the opportunity arose, and fill with the right stuff.

However ...

More gearboxes have been wrecked in less time using too THICK an oil, than too thin. That is a fact.

These remarks do NOT apply to axles with spiral bevels or hypoid bevels - just gearboxes. OK?

Landrover specify auto transmission fluid because it FLOWS very well, and the gearbox oil pump (where fitted) and the whirling gears will be able to pump and throw heaps of nice runny oil around the bits and pieces inside the box (like the bearings for a start) which lubricates them, COOLS them, and keeps them clean. Critically, Auto-trans fluid can reach ALL the tricky bits like synchromesh rings and cones. Heavier oil might not, and burned out synchro would be a certainty. Synchro rings can MELT in seconds if the lube fails.

Don't think that auto-trans oil can't be a good lube just because it is runny.

CharlesY

In LT77 or R380 gearbox use ATF or MTF oils although it depends what part of the world you are in, as ATF is far to thin for the hot climates, so then use normal EP gear oil it won't wreck your gear box, the only reason for using the light weight oils is to improve gear selection when cold.