Wanting to install a transmition temp guage
 

I was wondering if I can put a run of the mill, $20 sunpro oil/water temp guage in my transmition? I have a 700r4 transmition. There are 2 unused taped and pluged holes on the passengerside of the transmition abouve the pan. According to my chiltions, these are for the cooler lines. Could I just take out either the send or return plug and put the temp sender in that hole? Or would the acctual size of the temp sender interfere with something?

I found this pic on google, this is the kind of guage it is.
Attachment 13195

Are there not cooling lines going from the transmission into the rad?
Maybe on the drivers side?
Not familar with your tranny, maybe the stock rad cooler comes out of one side and the auxilary cooler lines come out of the other?
Kinda unusual if it does not have the in-rad cooler already.

Yeah I kinda wondered the same thing. When I noticed the plugs previosly described, I was working on something else, it just cought my attention. I never thought to look any see if there were tranny cooler lines anywhere else. I'm shure there are tranny cooler lines in my rad.

Installing the temp gauge prob into one of those plugged ports.......................
The thread of those ports might be straight threads for inverted flare tubing connections, eetc.
Versus pipe threads of the prob fitting.
Probe might be too long to go into either port all the way.
Using one of those ports might only read "dead fluid" since none is circulating thru an external cooler.
I can't recall GM ever installing a factory trans temp gauge so the ideal location is a toss up.
I think I would be inclined to install the probe to read the cooler line fluid.
Downstream of the cooler.

trans temp gauge
 

If you put the gauge in after the fluid has gone thru the cooler you wont be checking trans temp. Look on the drivers side right above the shft linkage for a pipe plug. You are going to have a plumbers nightmare of fittings to hook up whats in the picture. Autometer makes a gauge for this.

OK, well all of the above is kinda what I expected (in short, its not recomended). I just figured that the guage was free so WTH, why not ask. Thanks for your input everyone!

those plugs on the side of the tranny are actually pressure testing taps. a temp gauge should work there if it threads the same. i wouldn't change the threads on the housing. might make it hard to pressure test if needed.

I put mine in on a pressure test port and it worked great. That was in a 4l60e.

Yep, and he could also put a T into the trans, cooling lines on the right side of the trans. OR push the temp probe down the fill tube using an O ring and flared aperture cap to seal the tube instead of the dipstick.