Thread: R380 Gearbox Cooler Fittings

It's on an R380 manual gearbox.

All Australian TD5's, and some early Defender Tdi's and I think all Disco I V8's had the thermostat housing and cooler on the gearbox. As John mentioned, some Rangies with the LT77 also had the cooler fitted.

Most 300Tdi's don't have the thermostat housing on the box, just a blanking/transfer plate. They also have the tendency to 'kill' their lube pretty quickly, too.

Hi Rick 130,
Is the cooler an ordinary auto cooler or is it something special? Now I know why my gearbox is giving up the ghost because I do a lot of towing with it. I have never heard of a cooler mounted on the manual gearbox before.

The TD5 one just uses a steel pipe from the 'box up past the engine and back.
It still doesn't seem adequate when towing in our hot summers. I know of one TD5 that has had the gear hardening start to have a problem when the gear oil (synthetic) thinned too much when towing in 46*C + temps.

Early Tdi ones, and the UK Army 300Tdi ones use a dedicated cooler up in front of the radiator.
The t/stat starts to open at 87*C, so the boxes get damned hot.

Can anyone explain how the cooler is plumbed up such as is the oil pumped directly from the pump through the cooler then into the bearings. can a blanking plate be modified to do it and is a thermostat required.

Originally Posted by Bush65

Pic of mine below. The hose end fittings are JIC (37* flare).

BSP parallel fittings seal on the washer face. The Dowty washers can be seen where the fittings screw into the housing - they have bonded rubber seals with lips on both sides to seal.

Dowty is a UK aerospace company who also make hydraulic equipment. Any hydraulic shop or hyd hose company such as Enzed or Pirtek will know what you are after if you ask for Dowty washers - it tends to be used as a generic name now (like hoover for vacuum cleaners).

I don't know the origin of my cooler adaptor - obviously earlier than those you have. I do now that they were fitted to LT77's in some rangies that had the towing package fitted.

BSP parallel is in very common use for ports in hydraulic valves and cylinders. Tapered threads such as BSPT and NPT ports/fittings suffer from overtightening causing failure of valve bodies.

Thanks.

The fittings I used to seal on the gearbox face, rather than internally with the original o-ring seal.

I did however use and extra o-ring on the eternal face as the seal on the hydraulic fitting didn't look thick enough.

Thanks all.

Dave.

My 300Tdi Defender is one of those which has no R380 gearbox oil cooler, which I presume was due to some bean counter at Land Rover wanting to save money and possibly sell more gearbox parts later. Seems it is a good idea to instal one if much heavy work in hot conditions is anticipated.

Something someone who has had the same vehicle before and after fitting a transmission cooler could comment on: On a hot day, do you reckon it makes a noticeable difference to the temperature of the seatbase or in the cab? eg as extra airflow on the left side of the engine compartment seems to reduce the temperature of the left footwell which would absorb a lot of heat from the exhaust manifold and pipe.

What size hoses are used to the oil cooler and is an auto cooler big enough to do the job? Is a thermostat required?