Trans Fluid Temp Observation

I installed a SW temp gauge, the sender is in the line between the trans and cooler (out going fluid from trans before cooler) the temp will do almost immediate swings of 40 to 50 degrees depending whether the T/C is locked or unlocked.
I have a manual switch set up for shifting.

Am I correct in the thought that when the T/C is locked, there is no or very low fluid flow going to the cooler loop ?

If it shuts off when locked I could understand the quick drop in temp display on the gauge as the sender is in flex line, the wind stream behind the radiator.
The next time I have the trans pan off I will be relocating the sender to the pan.

Thoughts ?? .............

Fluid runs through the cooler regardless of the gear selected or the TC state. Curious here, are you saying the temperature drops when the TC is locked? If so, that sort of makes sense to me as the fluid is no longer getting "sheared" in the TC which generates heat.

But the idea that it will change "almost immediately" is quite foreign to me. That sounds remarkably like a gauge issue, not a transmission issue. Given the masses of fluid involved, fast temperature changes appears unlikely.

ME IN RED

O-Gauge Steamer said:

Fluid runs through the cooler regardless of the gear selected or the TC state. Curious here, are you saying the temperature drops when the TC is locked? YES, THAT IS CORRECT If so, that sort of makes sense to me as the fluid is no longer getting "sheared" UNDERSTOOD, HAVING WORKED WITH HYDRAULICS FOR YEARS in the TC which generates heat.

But the idea that it will change "almost immediately" IMAGINE A READING SWING FROM 200 TO 160F IN LESS THAN A MINUTE is quite foreign to me. That sounds remarkably like a gauge issue, not a transmission issue. Given the masses of fluid involved, fast temperature changes appears unlikely.

Click to expand...

Also, I haven't taken it for long drive with the TCU operating the trans, the observations were from a trip to the mountains and back using only the manual switch shift. (I guess I miss having a stick)

My sender is after the cooler on the way back to the trans, I see a pretty quick decrease in temp when the converter locks. Tons of heat is generated when its not locked, I could see a pretty good drop in temps in a minute.

X2 with the TC unlocked I will see a good increase in temps specially if you are driving on mountain roads with hills and more load on the trans. On the trail it always stays at 150-165. with the TC unlocked.