how do i hook up a transmission temperature gauge sending unit. i have a 94 trans am which im pretty sure has the 4L60E (its an automatic). With the sending unit is there already a unit that i can tap into to or do i have to tap into the pan.
Thanks alot guys

 

you need to remove the pan and weld a bung into it.

 

That the only way to do it? Has any done like a screw in type with gasket? Welding it it sounds like the best way to do it though.

 

you can weld a bung, OR you can screw it in the pressure port, its the same thread, but it will read 10' hotter

 

pressure port on the left side of the tranny by the linkages.

 

I have mine in the pressure port on the drivers side of the trans, just have to remember its 10-15 degrees hotter.

 

so pressure port definately sounds like the easiest way, cause i really dont want to weld my pan. but what should the trans temp be around. i have an a4 if that matters

 

Normal driving should be around 175 degrees
High range is 250 degrees

Just remember pressure port will read hotter.

 

ok thanks alot one more question will i have to drain my trans to put the sending unit in the pressure port

 

oh and what does the pressure port do anyway why can you just take it out and put the sending unit in. it wont hurt anything will it

 

Nope theres a plug there and you just remove it and install the sensor. The sensor acts as the plug while reading the temp!

 

ok thanks alot guys hopefully i get the gauge tomorrow

 

Yeah just like this..

 

What size fitting was used to screw that in there?

 

Size fitting... that is the sending unit, that is how it comes - just screw it in.

 

Most sending units are 1/8 NPT which is a tapered thread. I would recommend a little teflon tape. For those not wanting to weld, get a 1/8 NPT bung and pull your pan off and clean it, then go to your local muffler shop and have them seal it with a bead for a few bucks. Its worth it to have a pan reading as I believe this is the best average temp of the trans as a whole. From the pan I see about 120 in cold weather, 140 in warm weather and 170-180 in hot weather.

 

Pressure port is better place the go then the pan. I tried both. Pressure port was about 15 degrees off from what PCM said. Pan was more like 25-30 degrees off. Id stick with pressure port.

 

We arent seeking the pcm's approval of our gauge reading. We should be seeking the average temp of the tranny to indicate how effectively our cooling system is working. The pan is better suited for this. But if the port makes you feel all warm and bubbly then whatever....

 

That's strange because the factory sensor is located in the pan area on the manifold switch. With the aftermarket sensor being located in the pan that is kind of the same thing. I would have to think than that there might be a calibration issue with one or the other if this is where they were located. I personally do not like the pressure port for some of the reasons that have been mentioned in this thread. Also to add to this I have seen guys crack cases using the port. IMO it is just an easy cheap way to do it and not the right way to do it in my opinion and experience. As builders here we use that port to test pressures on our dyno not temp. We actually use the internal sensor and also have one locate in the return cooler line on our dyno to test temps. You guys do what you want but not me.



+1 ROTF

 

Vince, the reason why some people crack the case when using the pressure port (and you may already know this) is because the pressure port is a 1/8 straight thread. The sending units are 1/8 National Pipe Thread which is tapered like a triangle. Effectively you are wedging a triangle into a hole the shape of a cylinder. Thats what causes case cracks bc thats not the right way to do this. Seems like anyone who uses the pressure port is just plain being lazy. What I did with my pan when I added my bung, I added a seperate drain too. It was another 1/8 NPT bung and matching 1/8 NPT plug. That way from there on out I never had to drop a trans pan that was full of fluid. So I accomplished two things.