[redvers]

Hi All

Can anyone give me more info when towing with my 3.2DI-D. I have been told not to tow in 5th gear as this is not good for the transmission.

I intend to leave for hartenbos tomorrow and will be towing my caravan about 1200Kg loaded.

Thanks

[Bigwill]

I don't think that you need to worry about towing in 5th. I do that all the time. My car is an automatic and she knows when to change down to fourth. She will never allow the engine to labour too much. When running on an easy road there is no need to change down. If you had to run in 4th all the way to Hartenbos you can count on a dramatically higher fuel bill. Even driving in 5th your consumption could go up to 15l/100km. I hate to think what it will be in 4th.

[Bigwill]

Oh yes! The car's handbook states that you should engage 4H (Four wheel drive) when towing. That is to better spread the load across the transmission components. As a matter of fact I hardly ever put my car into 2H. The superselect is quite happy to run four wheel drive day in and day out. Gives me even wear on the tyres.

[4ePajero]

Although the 5-spd transmission on the Di-D is very robust, the general consensus is not to tow heavy trailers/caravans in 5th gear with any transmission.

I would make it more specific and say that 5th gear should be used only where there is little torque used, such as flat and downhill sections.
The moment you apply torque (uphills etc), rather use 4th.

[redvers]

Hi All

Thanks for advise. Trip went well and the PAJ towed like a dream. Sometimes had to remenber that I had a van behind me. Took the hills in 4th and never once had to use 3rd for the run of the trip except when pulling away and slowing when I could not pass a vehicle. Consumption was surprisingly good at 8,5km/l at 110 km/h. a lot less when doing 125km/h.


Regards

[RicardoE]

How did the Pajero do? Mine has 250 000Km on the clock and about 120 000Km done with Penta loaded with only the sink left at home. It is a brilliant vehicle. Just remember look after her and she will look after you.

[4ePikanini]

I drove in convoy from JHB to East London, where my uncle was towing a 2ton+ trailer with my dad's gen1 3.2 DiD. He never complained over lack of power and pulled away from us on the hills.

We were doing 90-105km/h and it did 12l/100km.

The double cab isuzu 2.6 petrol was driven by my brother and heavily loaded in the back but not towing and returned about 12.5l/110km
I drove an older camry 3.0 V6 auto with about a ton trailer and returned a smidgen over 10l/100km

I agree that 5th shouldn't be used when there is any torque given and 4H is a given.

[Bigwill]

I agree that 5th shouldn't be used when there is any torque given and 4H is a given.

I do not agree with this. The torque put onto the transmission is determined by the work required depending on the load of the vehicle and the gradient of the road. This will always be the same, whether it is produced in 5th gear or in 4th gear. Only difference in 4th will be the engine is revving higher and the input shaft to the gearbox is running faster. Your right foot still determines the load you want to produce, which is the required load for the circumstances. So by changing down you help the engine to produce more power which in fact could load the transmission more. One should only change down when the engine is dropping below its most efficient point on the power band. Transmissions are regularly loaded to maximum power/torque even when running solo. This happens every time you drive with your foot flat. It is the engine that needs to be protected from revving to low, but this does nothing for the transmission.

[4ePikanini]

I beg to differ. gear ratios comes down to leverage.

Imagine that your arms are the power holding onto a wall mounted surface and your back is the gearbox through which the power of your arms are transferred. If you stand on a heavy round steel plate and try to move it around in circles with your legs spread apart it is fairly easy and you can initiate and stop it quickly but if you close your legs and try to do it your back takes a lot of torque strain and can get hurt easily.

Same thing with gears. The smaller fifth gear needs to throughput more power per revolution than the bigger lower gears. This extra strain plus the inherent weaker characteristics of the fifth because it's smaller makes it easy to break.

[Bigwill]

Ok well so lets agree to disagree. In any case I do not like to stand with my legs spread apart.
I can tell you that in my days of racing I never broke a gearbox while in the higher ratios, but in first and second I did.