I believe the A340 is similar to some Jeep transmissions?
Either way after overheating a Jeep tranmission when heavy 4WDing, a mate fitted a gauge and better cooler and was seeing about 86 degrees C and the car ran a lot better with no overheating of the trans.
So I'd say anywhere from 83-87 would be the where you want it.
EDIT : More info here http://www.toymods.net/forums/showth...highlight=A340
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