I have an '01 with an automatic, I assume it is a 47RE. I'm in the planning process for installing, among other things, a transmission temp gauge. I want to put the sensor in the hot line so I need to determine which fluid lines on the transmission is the right one. Both lines connect on the left side of the transmission, one toward the front and one toward the rear.

Also, one of the lines crosses underneath the transmission and goes up to some sort of reservoir beneath the exhaust manifold. What's the purpose of that? The return line from that crosses back under the transmission and then heads up toward the radiator on the left side of the engine along with the other line directly from the transmission.

Any clues or links to sites with details?

Don

 

That would be your HOT line.
It runs from the transmission to the heat exchanger, before continuing to the tranny cooler near the radiator.
The other would be the "cool fluid" return.

 

Do they make a fitting to tap into that line?

 

I've seen other postings about a replacement line that was used prior to '96 that has a tee in it and will fit newer models. It's kind of expensive though ($80-$115) at the dealer. See the link below.

Thread about replacement line

I'm going to look at silver soldering or brazing a tee in the existing line. Others have used a compression tee fitting.

Don

 

just go to home improvement shop and get a copper fitting, when you cut the fuel line dont cut it too close to the curve edge. Because curve edge do not fit well with the copper fitting. I found out the hard way.