Oil Cooler for D4D Autobox

[Ulfie]

Greetings,

Has anybody made any experiences in trying to size an oil cooler to cool the auto transmission fluid of a D4D D/C 4x4? I am planning to take a caravan up to Zim later this year, and really can do without an overheating torque converter, boiling oil, popped seals, charred oil and so on.....

I had a look at what's available, but do not have the knowhow to calculate or determine what the optimum size of oil cooler should be. Too small is self explanatory, but too large cannot be good either as then the ATF does not come up to operating temperature... Between a hard place and a rock again....

Maybe somebody can recommend a suitable professional outfit in Gauteng that would be knowledgeable on these matter that I could approach for advice and or possibly perform the installation?

Thanks, Ulfie

[Andries]

Hoe groter hoe beter vir 4x4.

[pietpetoors]

This is what one guy who did several Lexus conversion suggested I use for the Surf with Lexus auto box, I see there is dimensions on the one picture as well.

Oil Cooler

oil-cooler (5).jpg (31.06 KiB) Viewed 3279 times

Oil Cooler

Oil Cooler

[pietpetoors]

Also see
http://www.hot4cold.co.za/products.aspx?prod=4

[Dirka]

On ATF coolers: - Bigger is Better. You can do no harm going too cold. Only limitation here is the space required for installation.
A surprising answer I got a while back from the pro's. (Still can't put the logic to it though)

One place I'd go to in Gauteng is Autobox in Koedoespoort. It is where Toyota send their transmissions to for repairs.

Their contact details is on website: http://www.autobox.co.za/index.html

Speak to Raymond. They do series/inline cooling which is nice.

[WayneSchalk]

I am also learning a lot on my fortuner as this is the first time I opted to go auto, from reading other guy's experiences with overheating it seams like the issue lies with the auto box changing gears, up and down. That is where the heat comes from, please correct me if I am wrong?

So I have changed the way drive with the auto, I find myself changing to drive to 3 quite often on uphills where the box changes between 4th and 3rd and especially when towing.

But it will be interesting to see what the experts say and what cooler you end up putting in

[Ulfie]

Hallo WayneSchalk,

Having gone into the topic a bit it appears it is less the gears changing that is a problem but more that the Auto box tries to use the highest gear at all times and to keep the engine revelations as low as the torque demand allows. This applies particularly when towing a heavy load, or driving in High range in soft sand. That puts a big torque requirement on the torque converter, and it gets hot, together with the rest of the box.

Keep the revs up, choose a lower gear, the torque required by the motor and torque converter drops and the heating of the Auto box is gone. But then the consumption of diesel is a bit of an issue, I do not like a diesel revving unnecessarily, nor straining if it is in a high gear. When towing, I find it is the long hills that give grief. And yes, I also stop any hunting by immediately intervening and selecting a lower gear.

And to Andries, Pietpetoors and Dirks - Thanks guys for your valuable information!