Turbo Diesel Rodeo Auto - Towing 1200 KG Van (loaded weight) up very steep mountains
rockylizard said
01:34 PM Jan 6, 2013
Gday...
I was taught that the "rule of thumb" was to maintain the revs of the motor either on, or upto 500rpm ABOVE, the RPM that the motor develops its maximum torque. Maintain that RPM by use of the gears.
e.g. - if the vehicle develops its max torque at 2000rpm, then begin the hill with the tach showing, for example, 2,500rpm, and then downchange as soon as the motor drops to no less than 1,900rpm. You may begin the hill in 4th gear/2,500rpm, then 3rd/2,500rpm, then 2nd/2.500rpm and if it is long enough or so steep, then you may be back to 1st with the revs above 2,000/2,500rpm. That means, maintain the engine revs and don't care about what speed you are doing.
[edit: with an auto box, usually if you manually select a gear (eg 2nd) then it will stay in that gear whether it is lugging or not. Therefore, I would be more at ease with D and then use the right foot to help the 'computer' to choose the gear it needs to maintain the required RPM. (others more knowledgeable than me will clarify perhaps) Otherwise, if you choose a gear "manually" use the tacho to change down BEFORE the motor begins to "lug".]
Usually, if the motor is kept 'spinning freely' and not allowed to "lug down" then the fan/waterpump are also 'spinning freely' and that keeps the water flowing briskly through the radiator - and cooling.
If you have a 4X4 and the hill is so steep ya run outta gears - stop and put it in low range, and take off in 2nd low.
Cheers - John
-- Edited by rockylizard on Sunday 6th of January 2013 01:40:27 PM
petengail said
07:03 PM Jan 6, 2013
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
briggspc said
07:36 PM Jan 6, 2013
Hi there, if it was me I would be using 2nd and taking it easy!
briche said
09:21 PM Jan 6, 2013
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
ibbo said
10:48 PM Jan 6, 2013
petengail wrote:
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
pete drive by the rev.counter,don't let the engine lug.make sure that the van brake is right off and not binding.
allinone said
04:45 AM Jan 7, 2013
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.
jimricho said
02:18 PM Jan 7, 2013
I regularly drive from Gloucester to Walcha which involves a long steep climb. I leave the gear in second for most of the climb and take it easy to avoid over-revving. I find I don't have have any problems even on a hot day.
PeterD said
08:53 AM Jan 8, 2013
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.
Ole_Grizzly said
12:17 AM Jan 10, 2013
First thing I add to my vehicle with auto-trans is an Oil Cooler.
Works a treat, no indication of getting hot and at service auto trans oil is clean and never has that common over heated odour.
Gday...
I was taught that the "rule of thumb" was to maintain the revs of the motor either on, or upto 500rpm ABOVE, the RPM that the motor develops its maximum torque. Maintain that RPM by use of the gears.
e.g. - if the vehicle develops its max torque at 2000rpm, then begin the hill with the tach showing, for example, 2,500rpm, and then downchange as soon as the motor drops to no less than 1,900rpm. You may begin the hill in 4th gear/2,500rpm, then 3rd/2,500rpm, then 2nd/2.500rpm and if it is long enough or so steep, then you may be back to 1st with the revs above 2,000/2,500rpm. That means, maintain the engine revs and don't care about what speed you are doing.
[edit: with an auto box, usually if you manually select a gear (eg 2nd) then it will stay in that gear whether it is lugging or not. Therefore, I would be more at ease with D and then use the right foot to help the 'computer' to choose the gear it needs to maintain the required RPM. (others more knowledgeable than me will clarify perhaps) Otherwise, if you choose a gear "manually" use the tacho to change down BEFORE the motor begins to "lug".]
Usually, if the motor is kept 'spinning freely' and not allowed to "lug down" then the fan/waterpump are also 'spinning freely' and that keeps the water flowing briskly through the radiator - and cooling.
If you have a 4X4 and the hill is so steep ya run outta gears - stop and put it in low range, and take off in 2nd low.
Cheers - John
-- Edited by rockylizard on Sunday 6th of January 2013 01:40:27 PM
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
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.
Works a treat, no indication of getting hot and at service auto trans oil is clean and never has that common over heated odour.
Best insurance for the towing vehicle.
Just my 2 bobs worth..