Thread: Extra gearbox oil cooler for towing Y or N ?

Originally Posted by matti4556

Hi Guys - added some photos and more explanation to my post above - hope it helps someone.
Matti

That’s a fair bit cheaper than the BDP kit for $600

Originally Posted by matti4556

Hi Guys - added some photos and more explanation to my post above - hope it helps someone.
Matti

Thanks for the post, looks great.
So what's the status? how much cooler does the transmission run?

My ATF has been running at around 100C the last couple of days towing the brick, so I'm 90% interested in an additional cooler to bring it closer to the recommended max of 93C - complete with "Deraile open at 80C" thermostat. I just happen to have just seen a brilliant explanation of what is required on this thread.

Originally Posted by gavinwibrow

My ATF has been running at around 100C the last couple of days towing the brick, so I'm 90% interested in an additional cooler to bring it closer to the recommended max of 93C - complete with "Deraile open at 80C" thermostat. I just happen to have just seen a brilliant explanation of what is required on this thread.

Wouldn’t worry about the thermostat.

Just drop a gear or 2 when the going gets hot. Engine runs cooler at higher revs too.

Originally Posted by Eric SDV6SE

Thanks for the post, looks great.
So what's the status? how much cooler does the transmission run?

Thanks for the good question Eric.
I didn't measure temps before I fitted the cooler. I had no instruments to do this measurement. But if you can imagine that in a non-modified system, the tranny fluid passes through the engine cooling radiator fluid; (its located in the cold end of the radiator) then what leaves the old system cooler back to the tranny would be very close to the engine coolant temp in the cold end of the rad - maybe more? Definitely hot and considering the thermostat is wide open at 95°C.
Has anyone measured the cold side of the rad when the thermostat is wide open? I guess that depends on the ecm commanding the fan and its duty cycle, vehicle speed, load, accessories, oil temp, fuel temp etc.

Now with the additional cooler fitted in series to "further" cool what is exiting the main radiator - and the fact I can keep my fingers on the brass return line connection (where on the input side I cant because its too hot), I am hazarding a guess that it might be around the 60-70°C mark. When that cooled fluid squirts its way back into the transmission it will be warmer again after passing the exhaust dump pipe (why do they do that!?) - hence my statement earlier that I doubt it would re-enter the tranny at "too cool" a temperature - but certainly cool enough to give the fluid (and the tranny) some longevity. I hope.

What spurred me on to do the mod in the first place was when stopping for an under bonnet check on a long drive one day and feeling how hot the under-bonnet temps can get. And when you consider that the radiator is dealing with cooling the coolant, the engine oil and the tranny oil and running a fuel cooler as well AND pulling hot air through it that's being dissipated by the aircon condenser right in front of it (and as mentioned earlier that's dumping a lot of heat), its under a lot of demand and the auto tranny fluid returning to the box when the rig is working hard on a summers day, can hardly be called "cool". Oh, and plus the fact i dropped $8K on a tranny rebuild, I thought $200 bucks worth of additional cooler might be money well spent and a bit of fun for one who likes tinkering with the car.
On my next trip in a few weeks, I will pause to measure the temp at the radiator outlet, the second cooler outlet and the tranny case and tranny pan. Maybe rad top right hand tank and bottom left hand tank if I can reach. (I only have an infrared thermometer bit that's better than nothing for $hits and giggles).

I have talked too much - I will stop now.
Matti

Originally Posted by Tombie

Wouldn’t worry about the thermostat.

Only 'cos I already have it.

Originally Posted by Milton477

Just drop a gear or 2 when the going gets hot. Engine runs cooler at higher revs too.

Prefer an additional cooling resource rather than dropping gears for 3-400 km.