I'm under impression that my gearbox, when it goes in limp home mode, starts to heat up the cooling system.

I think that, from some reason, when in limp home mode, the ATF gets warmer than usual, causing heating up of cooling system (i't doesn't overheat-> it warms up to 96-98'C, and fan kicks in and lowers it to 92-93'C).

There is a line that goes from the gearbox into the radiator, which does the cooling of the ATF, right? Now, does the upper line lead into the radiator or out of it?

Reason for this question is that I'm going to put a small radiator for cooling the ATF (oil cooler from a vectra GT or something like that), and I want the ATF to go from the box, into that small cooler, and then into the engine cooling radiator, and then back into the box.

So, i must know, which of the two lines leads ATF from the box to rad?

good thinking....

it just may be that the torque converter doesn't lock up...that may cause ATF to heat up, right?

I'm just in the process of repairing the box.