Interesting reading re autos. I have been monitoring my trans temps for a while now and with a bigger heavier van coming I will be interested in any change in temp and if I go down the tranny cooler path or not.
@Boots in Action the scenario you described when your light came on would probably be the same even with a tranny cooler. Driving at 20 or 30km you wouldn’t get enough air flow for the tranny cooler to help and it would of got just as hot. Now that you can see what’s happening with your temp gauges you could drive to suit and reduce temps. (Edit ive changed my mind , with a decent thermo fan attached to the cooler it would help),
Change my “sealed box” at 45k and all looked good but happy I didn’t leave it any longer. My temps will sit on 97 / 98 all day reagardless of how I drive. Around town, freeway manually selecting or left in auto. It takes a while to slowly climb but after 40ish mins it will hit the same temps every time. This is all with out towing. Even a beach run for about 2 hours it never hit 100 which surprised me.
Towing it wanted to sit at around 106 with the highest ever recorded was 109 up a very long incline sitting on 100km/h. I was in touch with local auto shop and these temps are normal and he didn’t recommend a cooler yet as I mentioned getting a heavier van and my concerns so his advice was to monitor temps with new van first. While still under warranty adding a cooler may give ford an out as they do not even offer one as an option but after warranty is finished I can see myself probably fitting one.
Only thing that caught my eye in above comments was regarding engine temps being affected by trans temp? What the theory behind this. I would of thought the radiator temp is going to be lower then engine temp and will regulate flow through the thermostate. It would only be when the radiator can’t keep up that outside influences like tranny could hurt it even more and then raise temps. As long as the radiator has enough cooling capacity it should keep engine at correct temps even if trans is boiling itself to pieces.
Hi @JT76 , thanks for your thoughts on what may have happened to my tug when pulling hard at low speeds, especially if ambient temp is high. The worst thing about all that was that I had no idea tranny temp was getting into the danger zone. Now that I have sensors monitoring what's happening in REAL time and telling me on screen, I think that it will certainly be better than "not knowing". Yes, an oil cooler would help when air flow was high. But the provision of a thermally controlled fan would be the answer if air flow was low and temp high - just like water cooling through radiator for engine. But is it needed in all cases?? Only monitoring like your local auto shop advised can tell, as each case (and tug and load) are different. Note my Colorado engine temp has never shown higher than 83C since fitting sensors which is a lot lower than your tug. Perhaps it is because I have no (or less) obstructions to air flow at front of tug. @Drover brought up this point when comparing his tug to friend's who had oil cooler fitted but more equipment attached to front of his tug - restricting air flow somewhat???
Do not forget that the engine temp is sensed just BEFORE water from hot engine goes to thermo and then through radiator for cooling. The heat exchanger for the tranny is normally at the bottom of radiator where the "coolest" water should be (after going through an efficient?? radiator) and therefore should be able to cool the tranny fluid somewhat. However, in doing so, it raises the temp of water going back into engine again. So if cooling margins are small, there is the potential for tranny temp to be not cooled properly which gets hotter and then heats up the engine temp also. It could also work in reverse if engine is not cooled down in the first place (partially blocked radiator?) resulting in less cooling ability for tranny fluid.
My full test comes up this weekend. I will let you know what transpires.