ZF Auto Trans Temp Sender
- Thread starter Rivet
- Start date
RDavisinVA
Technical Excellence Contributor
I have thought about this, but never decided where to take the reading.
Before or after the fluid has passed through the cooler or in the lower part of the pan.
Think the pan would be best.
It's where the oil temp is generally taken.
We have a few extra pans... hmmm might have to weld in a bung on the side where it will be safe during wheeling.
Rivet
Founding Member
I'd be interested in a pan with a a welded bung...if you're makin a couple.
Kevin88RRC
Well-known member
That's was my first thought. Switch out the idiot light for a proper sender / gauge combo.
RDavisinVA
Technical Excellence Contributor
Some of the lines do have an idot light sender, but I think a reading from the pan would be better.
Are you guys seeing these transmissions fail often? It seems totally unnecessary to me. Kind of like the temp sensor on an LT230...
Jeff B
Well-known member
On a somewhat related note.... you'd know more about failures than most of us! Have you seen many ZF failures?
And concerning cooling; I recently acquired the stock trans cooler for my D90 auto project.
I already had a smaller cooler on hand, so I was wondering... just how much cooling is necessary in a D90 that is never going to tow anything??
.
I have a temp sensor in line to the cooler closer to the engine.
The owner at Jaggi in Houston, Hans, told me that the fluid through the cooler reverses course when the trany goes into torque converter "lock-up". This can happen in any gear depending on where you have the shifter positioned D,3, 2,1. In D this is usually about 52 MPH.
So depending on where you think overheating is likely to occur, then choose the correct line in which to place the sensor.
For me, mine gets the hottest when climbing off road grades pulling a tent trailer. This occurs because the stock position of the LR cooler is below the radiator and does not gain any cooling air flow from the engine fan.
The fluid pipes coming from the 4HP22 can be referenced as upper and lower based on where they attach to the trany. The upper position line is where I have tapped into to get the hotter reading while in "lock-up".
Mine has never been into the "yellow" zone (250-300?F) and I have pulled some long grades in 1st gear (slowest air flow over a stock LR cooler). My gauge and sensor is made specifically for transmission fluid by WesTach. Most of the time the temp needle barely comes up off of the lowest reading
The owner at Jaggi in Houston, Hans, told me that the fluid through the cooler reverses course when the trany goes into torque converter "lock-up". This can happen in any gear depending on where you have the shifter positioned D,3, 2,1. In D this is usually about 52 MPH.
So depending on where you think overheating is likely to occur, then choose the correct line in which to place the sensor.
For me, mine gets the hottest when climbing off road grades pulling a tent trailer. This occurs because the stock position of the LR cooler is below the radiator and does not gain any cooling air flow from the engine fan.
The fluid pipes coming from the 4HP22 can be referenced as upper and lower based on where they attach to the trany. The upper position line is where I have tapped into to get the hotter reading while in "lock-up".
Mine has never been into the "yellow" zone (250-300?F) and I have pulled some long grades in 1st gear (slowest air flow over a stock LR cooler). My gauge and sensor is made specifically for transmission fluid by WesTach. Most of the time the temp needle barely comes up off of the lowest reading
Let me put it this way, if mine failed, I wouldn't hesitate to install a used one out of a non running vehicle.
I've towed with mine quite a bit and never had any issues. I have 170k on my truck now, but I don't know when it was converted to automatic. It definitely wasn't recently.