I don't have any temp problems, but i still have the check valve (truck still under warranty). My trans temp gauge is in the PAN, so what temp should I say "I better pull over."

My gauge reads 95-100 on the HWY and 110 in the city when I get off the HWY after many miles driven. Have not seen it get higher than 110 in the pan.

I am thinking 160* in the pan. or 180*.

Reason I ask is because the preferred place is the return line.

My tranny stays pretty darn cool because it has the aux cooler and my tranny pan is the deep pan with cooling tubes (derale).

 

Get concerned at 190, pull over at 200 (in the pan). Assuming a 30 degree rise in the guts, that leaves you a ten degree headspace before varnishes begin forming.

 

I also get worried when my trans temp gets to 200-210 in the pan.

You could also install a sensor in the return line and set up a switch to toggle between them.

 

This is good info. I would say that if your average temps are that low, then if you start seeing 180*-200* in the pan it is time to stop; you have something wrong.

I have my temp sensor in the test port on the side of the transmission. During highway driving, I see temps of about 110* and when running around town for extended periods of time it gets up to 150*. My fluid goes through the radiator and then through a large cooler before going back to the transmission.

I was pulling a 6,000# Bobcat & trailer across town last month and my internal temp went up to 190*. That is as hot as I have ever seen the temps on my gauge.

 

In the FAQ section, in the "Transmission" thread. Hammer posted a temp chart from TCI. Might help you.

 

Hhhhmmm.... Maybe its just me, but.... Knowing the temp of the fluid when it comes BACK to the trans, after going thru a couple (possibly) coolers doesn't seem like it would give a very good indication of what temp the trans is actually operating at. If your coolers are operating at a good efficiency level.... temp drop across the cooler can be pretty dramatic.

Wouldn't it be best to know the temp of the fluid coming OUT of the trans? And if that temp read high to the point of varnish forming, and the fluid breaking down, its time to start doing something different?

 

That is why I have my temp probe in the transmission itself. I am going to add another temp probe in the output line right before it goes into the radiator with a toggle switch to switch back and forth to see what the difference is.

 

the test port is no good for a temp sending unit, it only sees fluid in a few gears.

i put mine in the return line just because, the output line would have been a PITA to cut in half and install a compression fitting on. i see up to about 120* in stop and go traffic, but when i get up to 50mph in overdrive the temp drops dramatically to about 85* in 35* weather.

how were you planning to toggle b/w the two senders?

 

Which few gears does it see fluid in the test port?

If you put in a DTDP switch you can toggle between each sensor by switching to either side of the switch. When the switch is closed on one side, it will send the sensor Ohms to the gauge and when you switch it to the other side, it will send the Ohms from the other sensor to the gauge.

 

depends on which TEST port you put it in, as there are multiple. this is coming from MonteC. none are an accurate gauge of temp. pan and cooling lines are the best

might have to try that switch. just know realized the ouput line is easily accesible in the engine bay. i STUPIDLY was only looking at accessibilty near the trans