Yes, that was the first thing I asked/checked, but it only does this in Spain.
Those sump extensions are more for looks I think. All they do is increase the oil capacity slightly, so more oil gets hot. They also often foul the exhaust.
ashcroft-transmissions.co.uk
The viscosity would in theory be the same at "normal temperature" but a 75w140 would possibly maintain that viscosity longer?
We have had them not fit either way round. But in this case they would also have to lose their transfer box sump guard
I guess the next step is to determine where it's leaking from
That is for the gearbox not the transfer case. the military ones had the same setup.ROW spec TD5 got a "oil cooler" from factory - EU didnt for some reason - I would add one if your in hot places regularly. but I would add the expansion pan as its a good/cheap upgrade
R380 Oil Cooler Kit
When a Vehicle is sold in "Rest of World" (ROW) spec the R 380 gearbox is fitted with an oil cooler, in the TD5 Disco this is a "propper" cooler, in the Defender it"s just a steel pipe that goes forward to the rad, then loops back to the box (waste of time !). The European
This i think is the most pertinent reply, work out why it is leaking and replace the seals rather than trying to stop it leaking by adding thicker oil. What do they do with the vehicle to require a gearbox sump guard? the chassis does a fairly good job of protecting the boxs and unless you are doing some American style rock crawling all this is likely to be doing is reducing cooling and airflow around the gearbox's. Unlike diff and steering gearbox guards gearbox plates are not a common fit to every off roaded land rover so they must be a reason they have fitted one as everyone else who offroads their land rover happily manages without one, myself included.
I thought it worked as a heat sync eg. if the gearbox is cooler will pull heat out of the T case and if you then have the extra oil with an extended sump in the t-case this would then also help ? maybe wrong.
They increases the surface area from which heat can escape from the box, both through the volume of the oil and the actual surface area of the sump. They do help, but I wouldn’t expect anything over a 10% improvement.
