Keeping your ZF cool

[Road_Warrior]

Oil/air coolers are being run by many people, so like you say Dave, it's not really an unknown risk. It's just not manyfacturer tested.

The thing that stops me going this path is the fact that no manufacturers do and we all know how that like to save money if they can, so there must be a reason for the oem setup.

Ah yes but it wasn't that long ago when oil-air coolers were a dealer fit option on a Falcon (part of the HD towing package if I recall). And some cars (XG and XH Falcon utes) had them fitted from factory. Don't forget, the "old" Borg Warner/Ion LE95 4 speed autos were essentially the same operating principle as the 6 speed ZF - an electro-hydraulic servo unit acting as the valve body. Just it only had 4 gears and not as advanced in a design sense.

A lot of it could also come down to manufacturing complexity. The block-mounted heat exchanger is essentially part of the engine and when the engine is dropped in, the hoses are hooked up along with all the others. What might cost more in parts might save $$$ in terms of man hours. The oil-air cooler on the other hand would require special parts and some stuffing around on the part of line workers assembling the cars. Don't forget these modern cars are modular, they are all assembled in modules. There's no time for stuffing around with add-on parts.