Skinner

I installed a trans temp gauge in my pan and the needle has yet to move. It is getting to be winter here and the gauge on the truck dash max temp so far has been 120*F. Not sure where in the Trans Mopar takes their reading from. I have checked the gauge and the wiring and they are good. I have not towed yet to get the Trans really heated up. I installed a 100-260*F Autometer Factory Match gauge.

Typically what is the temp difference between the truck gauge and the pan gauge for you guys that have them installed? Not sure if I have a faulty sender or just a cool transmission.

KATOOM

Depends on how long you've been driving the truck and how cold it is outside. Even in freezing weather the transmission will register on a temp gauge. What truck are we talking about because I thought the 4th gens have trans temp in the gauge cluster...

Skinner

My 2011 has a temp gauge if you flip through the digital display. I have just upgraded to this truck from my 2005 about a month ago and the highest it has read is 120*F. I just installed a 3 gauge cluster on the A pillar (EGT, Boost and a 100-260*F Trans Temp) I have yet to move the needle.

KATOOM

So I'm not following you... Is this the 2011 or the 2005? Because you posted this in the 4th gen section.

Skinner

This is my 2011 Katoom.

It has a trans temp screen in the digital display you can skroll to. Max it has ever read is 120* F.

I have now installed an aftermarket 100-260* F gauge in my A pillar that reads direct from the fluid in the transmission pan. It has not budged yet. I have checked the new gauge and wiring and both check good.

So I want to know if others have the same set up, is there a difference between their digital screen temp and the temp reading directly from the pan.

As of right now I don't know if my sender for my aftermarket gauge is no good OR is there that much of a difference (at least 20*F) between the fluid in the pan temp vs wherever Mopar is taking their trans temperature reading.

KATOOM

But you said the 2011 has a temp gauge in the cluster... So if thats true and that factory gauge reads something but the Autometer temp gauge isnt showing anything then I'd say that something wasnt wired correctly during the Autometer installation. Even just to confirm your suspicions you can climb under the truck and touch the pan with your hand to get a rough idea of temperature.

Skinner

Yes but if they are taking their temp reading after the fluid leaves the transmission and before it hits the the cooler, it stands to reason that fluid would be a lot hotter than the fluid sitting in the sump pan.

Just trying to figure if my sender is not working or if there is indeed that much of a difference in readings between the pan and wherever they take their reading.

KATOOM

The hottest temp is going to be right before the cooler but the pan temp wont be much different...or not enough to matter in this situation. And I dont know for sure but I'm going to guess that your trucks transmission "cooler" isnt as much of a cooler as its a heat exchanger. Meaning its job is to keep the transmission warm in the winter and cooler in the summer.
Either way, the gauges should register heat unless your driving distances are really short and the ambient weather is really cold. So again, if the dash is telling you there's heat but the Autometer is not then I'm going to guess the gauge wiring isnt right.

Skinner

K thanks.

The gauge and wire harness tested to be working fine down to the sending unit in the Trans pan according to Autometer's test procedure. So I guess I will have to order up another sending unit.

FMB

While you are in a money spending mode, you may want to pick up an infrared thermometer. I've used mine quite a bit, mostly for taking temps of the trailer tires on long trips. A tire with low pressure (leak) will flex more and build up more heat. Catch it before it blows. This

sub $20 tool" target="_blank">sub $20 tool

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could be used to take the temp of your tranny pan to compare with the reading from your new sensor.
Back to morning brew . . .

Skinner

KATOOM

Yup... everyone should have a laser temp tool under their seat. Very handy.

Skinner

Just a follow up for future reference if someone else runs into this.

The trans temp sensor installed is in a new cast aluminum transmission pan manufactured by PML. It holds about 2.5 quarts more fluid over the stock pan. I checked the trans temp sensor and gauge with another thermometer in a cup of hot water before I installed the replacement sender (thinking the original wasn't working) and they read the same so I know it is reasonably accurate.

https://yourcovers.com/transpan_10304.php

My Autometer analog gauge reads 25 - 27*F lower than the digital trans temp readout you can manually scroll to on the dash. So far, it only registers when I am towing something. We will see come summer time if my transmission fluid gets warm enough to move the gauge under normal driving conditions.

jrs_dodge_diesel

I have never been a fan of temp probes in mounted in the pan, even though that makes for an easy install. It isn't an accurate representation of what is going on in the transmission. Your measuring the coldest fluid in the system.

I don't know where Ram mounted the factory sensor, but if you want the most accurate reading, put one in the hot line leaving the transmission.

What I see for normal reading with it in the hot line is 60°- 80° above the ambient air temperature when driving down the highway. (ex. if it's 85° outside, I should see the temp read about 145° to 165°) Stop and go in town as well as sitting at a red light and I can watch the temp creep up. Heavy towing uphill with the torque convertor unlocked and the temp will climb quickly. I get concerned when I see it hit 220°. Above 230°, the fluid stats breaking down, shortening its service life. And the hotter it gets, the faster it breaks down. 250° is really bad. Past that, parts inside the trans start getting damaged too.

Next chance I get, I will laser temp my pan and see what the difference in temperature is.