Transmission temp sending unit
 

I've bought a trans temp gauge and sending unit to put in my 98 Suburban (454 w/4L80E), but I'm getting conflicting information on the best place to install the sending unit.

Seems a lot of people recommend putting it in the line out of the trans to the cooler, which would show the hottest the fluid gets. The instructions that came with my gauge even recommend this location.

I'm inclined to install it in the pan though, which would better show me how effective my cooler is, and what temps the fluid is being supplied to the trans internals. Also it seems (from what I can find) that a lot of the stock GM temp probes for models that had a factory trans temp gauge are located in the pan.

Anyone know why so many seem to use and recommend the "hot" line out of the trans? Maybe I'm missing something and should put it there.

Post on the Deiselplace.com - they have a great forum

Install it in the Line Out to the Cooler. It will give you the TRUE running temp of your transmission.

You could PM articfriends here on OSO, I understand that he builds transmissions when his boat is running OK:D

I had a 2500 burban like yours.....i went and got a deeper pan and just drilled and taped the pan for the sending unit....easiest thing to do and if god forbid you screwup or it leaks etc...atleast you still have the stock pan to put back on.. :)

After digesting all the information I could find on this, it really seems to boil down to this: both locations are acceptable. The advantage to putting it in the hot line out to the cooler is that the gauge will respond almost immediately to changing loads etc. Put your foot in it going up a grade and the gauge will show it right away.

If you use the pan location, it takes quite a bit longer to show you changes in conditions.

I think I'm going to give the line out to the trans a try. And not that I'm going to do this (right now), but I think the trick setup would be one sender in each line, wired to a toggle switch. Then you could see how hot the trans is running AND how well your coolers are working.