How-To: Install a trans temp gauge in a 95+ GMT400 with a 4L60e

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JollyGreen

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^^^That looks really good. I'd like to put one in my 4L80, but I want it in the area where it's going to get the most accurate reading, which would be in the pan or the cooler return line.
 
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94Sierra4x4

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^^^That looks really good. I'd like to put one in my 4L80, but I want it in the area where it's going to get the most accurate reading, which would be in the pan or the cooler return line.

That's something I was thinking, depending on where that temp sensor is in the circuit relevant to the trans cooler, it would read higher or lower than the actual temps..
Where exactly is that port in relevance to the trans cooler?
 

JollyGreen

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That's something I was thinking, depending on where that temp sensor is in the circuit relevant to the trans cooler, it would read higher or lower than the actual temps..
Where exactly is that port in relevance to the trans cooler?

I believe that would be on the feed side of it, after the cooler. I'm thinking my first choice would be the line feeding the cooler (return) and my second choice would be in the pan. I want to know what the temp is before it hits the cooler, not after.

I looked at the Mag Hytec pans...holy ****!!! I'm not paying $325 for a cast aluminum pan, I don't care what it says it does. Personally i think you're gaining enough by getting one that holds 3-4 QTS more, and the fact that it's AL will dissipate the heat better. I don't know if I could justify spending that much on it. Maybe $200, but even that is pushing it.
 

94Sierra4x4

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I believe that would be on the feed side of it, after the cooler. I'm thinking my first choice would be the line feeding the cooler (return) and my second choice would be in the pan. I want to know what the temp is before it hits the cooler, not after.

I looked at the Mag Hytec pans...holy ****!!! I'm not paying $325 for a cast aluminum pan, I don't care what it says it does. Personally i think you're gaining enough by getting one that holds 3-4 QTS more, and the fact that it's AL will dissipate the heat better. I don't know if I could justify spending that much on it. Maybe $200, but even that is pushing it.

Yeah, it would be neat to set up a temp gauge before & after the cooler. (No point having both, but, would be neat to see how much the cooler actually cools. :))
 

Mschaffer92

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Needed to sub so i dont lose this one..like many others that i cant find again..

Sent from the over used computer that is a phone
 

great white

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I use the obdii data stream:

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Thats Torque Pro on Android, but I also use Dashcommand on iphone
 

usar17

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Reviving and old thread. Great white do you think that would work with the OBD1 system? I have a 94 setup that I installed on my 1985 square body. Was curious if I could just use the signal that goes to the PCM or if a separate sending sensor is needed.
 

Blue95

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Sub'ed as I just ordered my Autometer Z series guage to do this same install, great write up and pics! I am using teh Z series as it is only $45 and has twist lock base so I can replace the bulb.

I think this is sticky worthy.

OP, where did you find the SEM paint? I have the code for my blue interior, but having trouble finding the paint.
 

someotherguy

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For those debating where to place the sensor, I've done this on two different transmissions (4L60E and 4L80E) by using the pressure test port as OP did. Took the truck out and beat it mercilessly, then checked all over using an IR thermometer. Reading on the gauge was almost spot-on the hottest temperature I could find anywhere on the transmission - all around the pan, case, torque converter, etc. I have 100% confidence in using the test port as an accurate measuring point, and prefer it greatly over risking introducing another potential sudden-massive-leak point by splicing into a cooling line. YMMV.

Blue95 - you can get SEM at most auto paint supply stores. Be sure to get the adhesion promoter too, read and follow the instructions to the letter for the promoter and the dye. Very important to have some grease-removing cleaner. SEM suggests TSP (trisodium phosphate) which can be had at many (but not all) hardware stores, or you can also find TSP substitute (calcium carbonate.) I guess for something as small as a gauge pod it may not matter much; I did a whole interior with the stuff so I wanted it to be durable.

When I did my 1996 3500 it was just a wrecker, not a play truck - so I didn't care much how the install looked. I already had a gauge and switch for my helper air bags and a switch for my load lights, so I used an Autometer 3 gauge panel:
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Did a much cleaner install in the 1994 2500LD using an AMI GMP333 stereo delete pocket:
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Richard
 
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thunderstruck

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For those debating where to place the sensor, I've done this on two different transmissions (4L60E and 4L80E) by using the pressure test port as OP did. Took the truck out and beat it mercilessly, then checked all over using an IR thermometer. Reading on the gauge was almost spot-on the hottest temperature I could find anywhere on the transmission - all around the pan, case, torque converter, etc. I have 100% confidence in using the test port as an accurate measuring point, and prefer it greatly over risking introducing another potential sudden-massive-leak point by splicing into a cooling line. YMMV.
Agreed. Even if the pressure port isn't 100% accurate, it's still more than enough to be useful. There is no good reason to cut into the oil cooler lines and/or add a fitting, IMO. If you really don't want to use the pressure port, get a Mag Hytec pan or weld a bung in the stock pan.

It would be nice to able to tap into the sensor that's already in the 4L60E's, which is used to enable TCC lockup. You can do that on 96+ OBD2 trucks using a good scanner like great white's or an Aeroforce Interceptor gauge.

Blue95 - you can get SEM at most auto paint supply stores. Be sure to get the adhesion promoter too, read and follow the instructions to the letter for the promoter and the dye. Very important to have some grease-removing cleaner. SEM suggests TSP (trisodium phosphate) which can be had at many (but not all) hardware stores, or you can also find TSP substitute (calcium carbonate.) I guess for something as small as a gauge pod it may not matter much; I did a whole interior with the stuff so I wanted it to be durable.
There are three auto parts stores local to me: a NAPA, an O'Reillys, and an independent. I only found it at the independent store.

I just used an off-the-shelf Duplicolor Grease & Wax Remover when I dyed mine. I don't recall if I used adhesion promoter or not (which would have been Duplicolor as well), but the grease & wax remover is very important. Either way, the SEM has been holding up great!
 
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