traffic jam means your tranny isn't doing a lot of work. Not much chance for it to overheat when its not doing anything...
Also, do trannies use a thermostat or anything like that, or do they just constantly pump fluid to the cooler?
When you are in gear but not moving the trans is slipping, when it is slipping it is creating heat. To compound that there is no air moving over the coolers besides what little the engine fan moves at idle.
When I am sitting at a drive through or in traffic very long I put it in park, keep the brakes on if you are in traffic though so people don't think you are moving.
Yes, some transmissions have thermostats in them. My 2008 Toyota Tundra does, it don't start circulating tranny fluid through the cooler until the fluid reaches a certain temperature, as the overdrive/torque converter lock-up are temperature based. If the fluid is too cold overdrive/tc lockup will not happen.
Not sure if all auto trannies are that way just know of the Toyota Tundra's being that way.
As for the engine thermostat there's nothing wrong with putting in a lower temp one, I ran a 180 degree one in my 84 ranger. Never understood why they wanted these engines to run so excessively hot for.
My F-150 is like that too, no TC lockup until it reaches a certain temp. It lets the TC slipping create heat faster to get the trans up to temp.
I don't think it is a thermostat so much as it is probably a temperature switch that tells the computer what to do with the TC though.
The highter engine 'stat is mainly for emissions but it was likely taken into account with tolerances when they designed the engine. The hotter things get the more they expand...
The heater in my 84 Ranger worked just fine with a 160 degree thermostat or even no thermostat here in Idaho in the winter, my Bronco 2's heater works a little too well with the factory recommended 195 degree thermostat LOL, when you have to roll down the windows in below zero temps it works too well LOL.
With a new 2 core Explorer radiator, new heater core, new 160* stat and a 302 my heater flat out sucked here in a good Iowa winter. Just barely lukewarm and took forever to heat up the little standard cab. Per my mechanical Autometer temp gauge it ran 160* on the nose unless I let it sit and idle forever (20-30 minutes) and it would eventually kick on the 190* efan. Once you got it moving it would dive to 160* again. As far as heat pumps go a 302 should be better than most in a Ranger and it has a full liter over what Ford designed that radiator to have...
My '85 has a little slider thing that allows you to adjust the temperature of the heater that works pretty good so you don't have to use the windows to adjust the cockpit temp.
Yesterday I loaded a bunch of scrap metal in my truck. In doing so, I also removed the plastic tanks off of my F150's old radiator. This pic shows the trans cooler that goes through the radiator. It is much smaller than I had expected. Mine has the bigger radiator in it as well.
A fluid to fluid cooler is deceptive though, they are a lot more effecient than an air to liquid cooler. To use Will's analogy, to stick you hand a 400* oven doesn't feel too bad, maybe kinda good depending on ambiant temp. I don't think it ever gets cold enough to make sticking your hand in a 400* pot of water feel good though...
Liquid is just a heck of a lot better at transfering heat.
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