lrmonks

Member
Just changed the oil in my transfer box in my 300tdi 1997 Defender 90. I bought Millers EP 75w/80 GL5 mineral (API 4/5). I bought the oil years ago and only just had the time to change it along with all the other oils. Looking at the manual it states 75w/90. I realise it's a bit thinner but has anyone had any issues using this grade?
 
Probably fine for normal use, if you work your truck hard like heavy towing change. Normal use change a bit sooner than you otherwise would.
 
Just changed the oil in my transfer box in my 300tdi 1997 Defender 90. I bought Millers EP 75w/80 GL5 mineral (API 4/5). I bought the oil years ago and only just had the time to change it along with all the other oils. Looking at the manual it states 75w/90. I realise it's a bit thinner but has anyone had any issues using this grade?
they are all fairly similar in terms of their use unless you have a specific and heavy use for your vehicle. I have used it before when I had some let over and similarly have used straight 90wt before again when had some left over. Mine tends to be changed annually due to the mileage I go and most of it is unladen so I am not too fussy what goes in as it is regularly swapped out as mentioned above just change it a little early.
 
The mechanism inside the transfer box is pretty simple - it's a very basic two speed gearbox - so it's not as if it has intricate components that need a specific viscosity of oil in order to work.
The primary gearbox is a bit more particular, and people have reported problems with anything other than MTF94 (or very near equivalent) in the R380 as the synchromesh mechanisms need a specific viscosity in order to work, but the transfer box is not so fussy.
 

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