Transmission line in radiator (Trans. Temp Gauge)

[JSteward]

Instead of drilling and tapping into the transmission oil pan, wouldn't it be more prudent to just put a three way into the transmission cooling lines and put the sensor inside a "T"?
Which line is comming from the transmission on a '96 radiator?

Thanks.

[bcbigfoot]

I think you would tend to see spiked high and low temps. I don't think you would get a real reading of the oil being used by the trans. Also most info on proper trans temp refers to pan temp so getting readings from the trans line would mean what? nothing to refer, so you would wonder if the trans is over heating or is that the proper temp in the line.

I have been told that putting a sending unit in the pressure port of the trans just above the shifter is a good place. I put mine there and seems to work well.

[soulman67]

I have mine in the trans line to the cooler, down next to the tranny with a tee. Its a B&M trans temp gauge and it said in the directions to put it there. It work great, and stays at a steady between 160 and 180 degrees while running down the highway at 75. While towing a 24ft gooseneck and a FSJ waggy it will get up to 200 degrees. But thats towing nearly 12k but it doesn't jump around. The only problem I have is pulling the wire off the sender when driving through brush and tall weeds.

[JohnC]

The line from the trans to the cooler should be very close to the pan temperature. Fluid is pumped from the pan and splits. Some goes to the trans and the rest to the cooler.

[JSteward]

I think you would tend to see spiked high and low temps.

I have been told that putting a sending unit in the pressure port of the trans just above the shifter is a good place. I put mine there and seems to work well.

How does the oil temp. spike up outside of the transmission? Maybe I don't understand exactly what you mean.

Also, how do you get access to the "pressure port"? What side of the transmission should I look from? Do you remember the size of the threaded portion of the "T"?

Thanks

[JSteward]

The line from the trans to the cooler should be very close to the pan temperature. Fluid is pumped from the pan and splits. Some goes to the trans and the rest to the cooler.

I wonder how I could find out the size of the threaded portion of the line so that I could buy a "T" to go in. Also, is the line comming from the transmission on the top or bottom?

[bcbigfoot]

Oil from your torque converter goes to your trans cooler because it is the hottest oil so when your climbing a hill with lockup torque converter disengaged the torque conveter will raise the temp in the oil line very quickly, say to 220F but the rest of the trans and trans oil is only 160F. Then going down the hill the torque converter isn't working and the temp. may drop to show 140F, but the rest of the trans and oil in the pan has maybe raised to 170F. Trans pan oil temps don't move very fast, it takes over 10miles to just get it to operating temp.

I remember being told when I went to trade school as heavy equipment mechanic that it only takes a 10 second brake torque to cause the oil in the torque conveter to get to boiling temps of over 300F.

If you have a 4l80e trans (I think 17 bolts to hold pan on and the 4l60e has 16) there is a 1/4 inche plug on the drivers side just above the shifting shaft and the 11 wire (large electrical terminal box) Its super easy to do and thats were the temp senders are put in most RVs and motorhomes.

[JSteward]

Oil from your torque converter goes to your trans cooler because it is the hottest oil so when your climbing a hill with lockup torque converter disengaged the torque conveter will raise the temp in the oil line very quickly, say to 220F but the rest of the trans and trans oil is only 160F. Then going down the hill the torque converter isn't working and the temp. may drop to show 140F, but the rest of the trans and oil in the pan has maybe raised to 170F. Trans pan oil temps don't move very fast, it takes over 10miles to just get it to operating temp.

I remember being told when I went to trade school as heavy equipment mechanic that it only takes a 10 second brake torque to cause the oil in the torque conveter to get to boiling temps of over 300F.

If you have a 4l80e trans (I think 17 bolts to hold pan on and the 4l60e has 16) there is a 1/4 inche plug on the drivers side just above the shifting shaft and the 11 wire (large electrical terminal box) Its super easy to do and thats were the temp senders are put in most RVs and motorhomes.


...you don't sound like a "newbie." :cool:

[JohnC]

I forget which line it is on the trans, but it's the top one on the radiator. The oil going to this cooler comes directly from the pan, in bypass fashion, via the pump.

[ZZ]

Tranny fluid flows in the radiator through the bottom and out the top.

[JohnC]

Tranny fluid flows in the radiator through the bottom and out the top.

I believe that's true of the 700R4 but not the 4L80E. But, I don't want to get into a pi$$ing contest.

[ZZ]

John, I think you're right. Seems like I have read that. I should've thought before I posted that.

[JohnC]

I should've thought before I posted that.

No problem. In fact, I told a friend with a 350/700R4 that it was the top one. He ended up making a big mess using it to drain his trans. Wouldn't let me hear the end of it when the fluid came gushing out of the radiator instead of the tube...