The other week I was towing the van along the old Armidale Road from Grafton NSW to Armidale.  By the time we got to the top of the plateau the heat indicator was showing well up into the hot area although not in the red.  My quetion is, should I be towing up very steep and long inclines in drive, 3rd or 2nd gear?  Cheers Pete 

As far as my thoughts are, you need to be in 2nd gear and don't rush it just let it take it's time and things should be ok. Just keep any eye on the temp gauge and at the first sign go getting too much, give it a rest for awhile. Brian

I also drove up those hills recently, 4.0lt non turbo diesel manual. It involved lots of gear changes and slow speeds. Coming back to dorrigo then belligen filled up and some ot the best fuel consumption ever?? Not sure about gears on an automatic though. We were in mainly 2 or third going up.

A lot of people think of a converter as being a simple connection between the motor and the gear box (transmission.) The fact is that it is a hydraulic gear box as well as a clutch. Your manual gear box is a mechanical torque converter, it converts the torque from an engine to a higher torque at a lower speed. See - http://en.wikipedia.org/wiki/Torque_converter  - to see how a torque converter works.

From that you will see that the torque converter has a higher conversion figure at low speeds where the difference between the input and output speeds is the greatest. At higher speeds there is not much torque conversion. The heat produced in the converter is maximum where the unit is working at its maximum. Where the converter is not doing much work there is far less heat produced. The engine speed where the two elements approach the same speed is give or take 2500 RPM in a typical 4WD transmission.

To minimise heat production from the transmission you need to keep your revs above 2500 RPM. When ascending long hills if you let the transmission to its own devices you will finding that it will tend to select a high gear ratio and thus keep the revs down. I had similar problems on the run that petengail had his overheating problems. When pulling up the Gibraltar range your speed is limited by the curves as much as the gradient. I had the gear box light on the Disco II come on. I immediately pulled the box back a gear and within a few hundred metres the light went out. I would suggest using your gear selector to keep the engine speed over 2500 RPM, preferably up around 3,000 RPM to make sure the torque converter is not doing much work and thus not generating much heat.