I'm thinking about replacing my coolant-ATF heat exchanger in my Jeep to an external cooler because of possible water contamination. The problem is, 95% of my driving is short trips, and I think the "cooler" actually acts more like a warmer for the ATF. Is it as important for the transmission to be up to operating temp as it is for an engine? Would it be a bad idea for a short trip driver to get rid of the ATF "warmer"?
Do transmissions need to warm up like engines?
- Thread starter SecondMonkey
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I have an 08 Liberty and was reading in the Owners Man that if the temperature outside is very cold it was normal for the transmission not to shift into OD until it warmed up. Flip side is if its in a situation where it is over-heating it won't shift into OD either. Since its been many years since I owned a new vehicle this was news to me.
I was taught that an AT had to warm up to function as it was designed to.
HTH,
Frank
I was taught that an AT had to warm up to function as it was designed to.
HTH,
Frank
Hi,
yes they need to warm up. Many devices in the modern AT are temperature sensitive
As a example a 928 Porsche V8 S4 (4spd MB Autotrans) has both an intercooler to speed warm up and an "air to oil" cooler to keep the temperature within the narrow operational heat range. All thermostat driven of course. This AT is mounted at the rear of this front engined water cooled car
Torque converter lockup operation is usually driven by temperature - in my Tiptronic transmission this occurs at around 45C
yes they need to warm up. Many devices in the modern AT are temperature sensitive
As a example a 928 Porsche V8 S4 (4spd MB Autotrans) has both an intercooler to speed warm up and an "air to oil" cooler to keep the temperature within the narrow operational heat range. All thermostat driven of course. This AT is mounted at the rear of this front engined water cooled car
Torque converter lockup operation is usually driven by temperature - in my Tiptronic transmission this occurs at around 45C
For an all season vehicle, you want that 'warmer'.
Remember also that you are taking away the cooling, when needed!
I'd start shopping for a radiator.
Remember also that you are taking away the cooling, when needed!
I'd start shopping for a radiator.
Your fuel mileage will suffer slightly in the winter months if you go with an oil to air cooler.
I assume torque convertor lockup delay is to warm the trans up quicker and not put the engine under high load/low rpm when it's cold. In my car it's based on engine temp, not trans temp.
While I'm sure the cooler/heater helps warm the trans in some situations, and stabilize temps, if I drive my car right away, my trans would be warming the engine coolant. I've had my girlfriend put the car in drive dead cold and lightly stall it to 1,200rpm which is a very light load and the external cooler starts getting warm within 20 seconds. This is a fairly tight stock convertor in the TL. I won't even mention what kind of heat the 3,800 stall in the other car produces.
While I'm sure the cooler/heater helps warm the trans in some situations, and stabilize temps, if I drive my car right away, my trans would be warming the engine coolant. I've had my girlfriend put the car in drive dead cold and lightly stall it to 1,200rpm which is a very light load and the external cooler starts getting warm within 20 seconds. This is a fairly tight stock convertor in the TL. I won't even mention what kind of heat the 3,800 stall in the other car produces.
My car has to trip the center point of the temperature gauge before the torque converter will lock up, and has to hit 60 degrees F to shift below 3500 rpm under any load. If I am on cruise control it runs 2400-ish rpm until it hits temperature, then suddenly drops to under 2100 as the converter locks up.
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