Thread: LT95 ransfer case oil

Can't comment on it specifically, but I do remember a carrier working for us (Mac Clarke from Andado) when I was in the Simpson Desert in the sixties changed to the then very rare synthetic oil in his transfer case for sandhill work in a Leyland Super Hippo 6x6 - stopped the problem he had of the oil boiling regularly.

John

you do realise that most 75w-90 gear oils are the same viscosity as a 15w-40 engine oil.
If you have a thrust washer wear problem I'd be jumping that way due to the extra EP component of the gear oil.
If you are worried about copper/bronze discolouration, use a good synthetic 75w-90 as most nearly all are buffered to prevent reaction.

Yes, most synthetic oils result in a temperature drop in use, (better heat transfer, better coefficient of friction) although a really well blended mineral oil can also do this.

I believe that the recommended T/case oil for Defenders is 80-90 EP whereas the recommended for Discos is somewhat lower viscosity synthetic - probably close to what you are now using Justin.
Any comments re different grades.types for basically the same mechanicals would be welcomed.

I get so much heat generating from the gearbox area at times that I can't touch the seat box and left leg gets uncomfortably hot. It has been suggested that part of the cause (apart from oil type) is that heat from the turbo gets trapped around the gearbox area - I've even been considering ducting from cooler air down there to alleviate the problem.

IIRC, LT 95 recommended lube was engine oil, usually 15w-40.

LT230 is SAE 90, 80w-90 or late ones are filled from the factory with a semi-synthetic 75w-90. Note this is not a thinner/lighter viscosity oil as at 100*C it is the same viscosity as an SAE 90, and usually thicker at even higher temps. It just flows better/is thinner at sub zero temps where a straight 90 becomes treacle.

Thanks for the clarification rick130

Originally Posted by Xtreme

I believe that the recommended T/case oil for Defenders is 80-90 EP whereas the recommended for Discos is somewhat lower viscosity synthetic - probably close to what you are now using Justin.
Any comments re different grades.types for basically the same mechanicals would be welcomed.

I get so much heat generating from the gearbox area at times that I can't touch the seat box and left leg gets uncomfortably hot. It has been suggested that part of the cause (apart from oil type) is that heat from the turbo gets trapped around the gearbox area - I've even been considering ducting from cooler air down there to alleviate the problem.

If you look at where the air from the engine area can go, it can only go back under the vehicle. Some will escape between the chassis and engine downwards and out into the wheel arches, but as hot air tends to ride a lot of it will be funnelled into the transmission tunnel, which while it may be a good idea for the UK is less so here. Aft of the seat box it will spread out, and mostly get out the sides in front of the rear wheels, although at speed a lot will go out the back.

I think that this is the major source of heat in the transmission area, and adds to locally generated heat. In addition, the bell housing will be a reasonable conductor of heat from the block.

The best way would be to divert some of this heat, but the only real way I can see of doing this would be to have vents in the bonnet (they would have to be large to have much effect) and do you really want to have the oily, hot, air from the engine onto your windscreen?

John

Originally Posted by JDNSW

The best way would be to divert some of this heat, but the only real way I can see of doing this would be to have vents in the bonnet (they would have to be large to have much effect) and do you really want to have the oily, hot, air from the engine onto your windscreen?

John

I was thinking more of ducting from the area of the front bumper - it would avoid the 'oily, hot air from the engine onto your windscreen' and eliminate the need for fancy panel work and associated respraying.

Im not sure but I thought that some applications of the LT95 transfer case had fins on the bottom cover to overcome the heat problem??