Towing with the Auto

[stewydz]

I have just finished setting up the Nav to tow our trailer and was wondering has anyone had issues with the auto overheating.?

Do I need to fit a tranny cooler straight away?

Had heaps of dramas with our Prado and didn't find out until half way to the cape.

[happy john]

Originally Posted by stewydz

I have just finished setting up the Nav to tow our trailer and was wondering has anyone had issues with the auto overheating.?

Do I need to fit a tranny cooler straight away?

Had heaps of dramas with our Prado and didn't find out until half way to the cape.

Can you supply the weight of your trailer?.

[Old.Tony]

I was just thinking that in Australia, a "tranny cooler" is a Vodka Cruiser on ice held by what appears to be a woman.

I would expect a camper trailer to peak at around 1500Kg. They generally don't like more than about 750Kg per wheel, and since camper trailers are usually exclusively single axles, any more than 1500Kg makes the choice of tyre rather important - you can't use normal off-road tyres, you have to move to LTs.

Since the cops have been pulling over caravans and weighing them (it's not a myth this time) it's something to be very, very careful about. They've been looking at GVM, GCM and caravan's loaded weight alone (GTM). What's misunderstood by many (and not an issue here for the OP) is that the Gross Trailer Mass - the total mass of the trailer - is checked against the max allowed to be towed. They don't subtract the ball weight, BUT the ball weight is added to the tow vehicle's load (GVM) and checked.

It's correct. Example: 2T trailer, 200Kg ball weight. The tow vehicle has to be able to support that 200Kg ball weight on its suspension (not the caravan's suspension). However, the tow vehicle is pulling 2000Kg, not 1800Kg.

Anyone towing up towards their GCM need to take care. A weighbridge costs about $40. The fines are several hundred $ if you're overweight and in some cases they're stopping you from continuing until the weight issue is resolved or the rig gets towed.

[Tappet]

It's probably not a bad idea to fit one. Every deg. you can lower the transmission temperature will result in increased longevity.

Some Navaras do run on the warm side when towing so the added benefit of the trans. cooler is is it takes that extra thermal load of the engine cooling circuit.

Probably the only hassle is find a place to mount it particularly on D40's . With the radiator, intercooler, AC condenser and steering cooler it's getting tight in there.

[stewydz]

That's why I asked the question OLd Tony.

My Trailer is a tandam and is around 2400kg loaded.

So I thought Id sort it before we left if there might be a over heating issue.

And yes the tyres are LT's.

[Old.Tony]

Yep, she looks heavy alright.

A tranny cooler is not an absolute requirement - we towed without it for 10s of thousands of km, but as pointed out, every degree you save adds to the auto's lifespan so it's a good move.

Be aware that because the radiator isn't warming the transmission fluid up, you'll find that the auto box may not engage its TCC until the gearbox warms itself up. I don't have an auto transmission temp gauge, but my coolant temp on cold mornings generally needs to be 55C or higher before my TCC will engage (and below 0C I have to wait until my coolant is over 60C).

[KevinE]

Two things that change everything are a high ball weight & lowered tire pressures on the car & trailer.

This combination, very often seen with off road camper trailers, will overheat most auto trans, whether you run a cooler or not.

You may not notice it while cruising at speed, but once the engine is stopped for a break like lunch etc, you'll get the temp gauge heading north as soon as you start to move off again.

I notice that the OP originally had a 150 Prado; I know from an acquaintance's experience that they suffer this. He tows an off road Kakoda caravan. He swapped the 150 for a MUX & problem solved.