Transmission Temp Gauge install w/pics

baldilocks

Battle Ground, WA
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Jan 29, 2014
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Battle Ground
Recently I installed a AutoMeter factory match trans temp gauge. I installed the sender in the pan and normal driving even when ambient temps are 95ish produces about 140-145. I have seen it as high as 175 while my 6000lb. 80 propels itself down the Rubicon when it's 90ish outside and that's a very hot day at 6500ft elev.
The oil in the pan is representative of the core trans temp because that fluid just lubed the guts and then fell into the pan immediately after returning from the cooler. In my experience with learning and building the trans in my diesel pickup, the fluid that exits the trans and heads toward the cooler just left the toque converter where tremendous heat can be generated during certain times. Times like when you are forcing your beast up a mountain road with converter unlocked or rock crawling on a hot day. Cruising with converter locked always renders lower temps due to no internal slip in the converter.
It's true that ultimate fluid temp is what destroys the fluids ability to lube your trans but putting a sending unit in the out line can induce a lot of unnecessary worrying because that's the hottest fluid in the system and its only that hot for a moment until it reaches the radiator.
A premier performance transmission builder here in the U.S. (Goerend) advised me to put the sender in the pan of my built 48re in order to monitor actual average transmission temp with out the dramatic spikes that can happen in the line from the converter to the cooler.
I also carry, in my vehicle, an inexpensive infrared thermometer as a second reference and it has shown my gauges to be accurate thus far. It's nice because you can monitor temps anywhere on the vehicle or even check for fever. :)
 
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Bend, OR
Cool mod but I heard watching trans temps on the 80 was about as boring as watching paint dry.... Has anyone seen it spike into the range of concern?
 

flintknapper

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Deep East Texas
Cool mod but I heard watching trans temps on the 80 was about as boring as watching paint dry.... Has anyone seen it spike into the range of concern?
Never. Not even towing in the hot summertime. On the highway (depending on time of year) mine stays a boring 130-140° F.) In town (summertime or towing) it might go 165-175°F at most.

Temps definitely rise anytime the Torque Converter is not locked up...or when conditions are such that there isn't good air flow through the transmission tunnel, but never into a range of any concern. If there were an easy way for folks to just 'test' their unit and see how it is performing, most would not go to the trouble to install a gauge permanently.

Actually, my IR temp gun reads really close (withing a few degrees) to what my gauge reads...when I shoot the middle of the transmission pan. I'm sure I could get it to go up around 200 if I were towing something heavy over mountain passes...but average person probably doesn't need to monitor their trans temp.
 
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