Parts needed and cost:
SunPro Water/Oil Temp Guage(Advance Auto) $16.96
3/8 Galvanized Tee $3.50+/-
3/8 Flare(male)/3/8 Pipe Thread(male) Connector $1.49 x2
3/8 Flare Nut $ .79 x2
Wire splice connector

Tools Needed:
Drill
Tubing Cutter
Tubing Flare Tool

http://www.explorerforum.com/photopost/data/503/medium/Explorer_001.jpg In this pic I have fittings to connect to the rubber hose coming from secondary cooler. This location did not give very accurate reading so I moved location of sensor to before main radiator.

Remove center console compartment area by just it pulling up. Drill hole in upper compartment large enough to get sending unit threw. Run cable and wires threw hole and mount guage. On '98 XLT there is a wire harness connector behind console compartment. Locate red wire with black strip, this goes to dimmer switch. Use a wire splice connector and attach red wire from guage to the red w/black strip wire. Attach ground wire from guage to metal bracket that holds side of center console. Run cable from guage threw back of console and out by gas pedal.

http://www.explorerforum.com/photopost/data/503/medium/Explorer_010.jpg

http://www.explorerforum.com/photopost/data/503/medium/Explorer_006.jpg

Run cable up and over brake pedal and steering column. Locate where emergancy brake cable goes threw firewall. Remove rubber gromet from firewall and make a small cut, run sending unit and nut threw gromet.
http://www.explorerforum.com/photopost/data/503/medium/Explorer_009.jpg
Locate where cable went threw firewall under the hood. Look directly under brake master cylinder. Pull excess cable threw firewall (you may want help feeding cable from inside so as not to kink line).
Remove tranny lines from radiator, you need to remove both so you can pull upper line up enough to cut. You may want to use a small pan to catch tranny fluid that will leak from lower line. With tubing cutter cut upper line about 3in from lower bend. On lower part of line that was just cut cut again about 2in down.
http://www.explorerforum.com/photopost/data/503/medium/Explorer_008.jpg
On both ends of line install Flare Nut and use flare tool for 3/8 tubing and flare ends. Lowe's has flare tool for around $10.
Use pipe tape on all threads. Insert the 3/8 Flare(male)/3/8 Pipe Thread(male) Connector into tee. Insert 3/8 adapter that comes with guage for the sending unit. Install tee on lower line and then install upper part of line onto tee. Reattach tranny lines to radiator. Insert sending unit into tee (be carefull not to overtighten, adapter that comes with guage is very soft brass, I stripped it and had to but another guage just for the adapter). Use wire ties to secure cable from guage.
http://www.explorerforum.com/photopost/data/503/medium/Explorer_011.jpg

Go for a short drive to warm transmission and check level of tranny fluid.
Let me know if this is helpfull and if I need to change anything.

nice write up man ill be doing this after i get my tranny situation under control...

Maybe Im missing something, but you say to install flare fittings, but Im looking at barb fittings in your pics. Using these barb fitting, couldnt you install this temp gauge in line with the aux cooler. Mine are done with rubber hose so....

Where you have the sensor, is that in the line that goes back to trany or coming from trany?

http://www.explorerforum.com/forums/showthread.php?t=176798&highlight=transmission+temp+gauge

Ok, it can be done either way it looks like.

THANKS. I always appreciate a good photo illustrated how to thread !!

Gonna sticky this a bit to insure it gets adequate exposure for the work you put into it!

Nice write up! Why did you use a galvanized tee instead of a brass tee? All of the fittings going into it are brass.

Maybe Im missing something, but you say to install flare fittings, but Im looking at barb fittings in your pics. Using these barb fitting, couldnt you install this temp gauge in line with the aux cooler. Mine are done with rubber hose so....

I explained in thread that I first installed it at the secondary cooler but could not get an accurate reading(temp. was too cold on the downside of both coolers to get reading on guage). I moved it upstream of the radiator and know I get the temp coming out of the tranny.

I had to use the galvonized tee in order to get clearence for the sending unit to allow better flow threw the tee. The 3/8 galvonized tee is bigger than the 3/8 brass tee.

I had to use the galvonized tee in order to get clearence for the sending unit to allow better flow threw the tee. The 3/8 galvonized tee is bigger than the 3/8 brass tee.

Yeah, the brass "probe manifold" T is an expensive part--about 25 bux, It has to have a real deep center neck for the probe.
Good idea!!!!

They make extension couplings which could be used, but they add to the cost, and bulk of the project.

Great write up.

Great write up! Love the pics!

Good write up. Mines going in once I finish the tranny leak. Would the pan have a more accurate reading then in the tranny line like your set up.

The pan would be more accurate but it requires more work to install the sensor.

ExploreingNC, Is the gauge you used mechanical or electric? Great deal for $16

I'm guessing it is mechanical- the cable that goes from the gauge looks pretty big. Mine is electric, didn't include a cable or wire, I had to run my own.

I see that this thread is a sticky in the transmission section as well as in this towing section. This was the first time that I saw this done on this forum.

I see that this thread is a sticky in the transmission section as well as in this towing section. This was the first time that I saw this done on this forum.

I thought I'd try it, I copied the thread- so it appears in both. Just seeing how it works out.

The information is valuable, and applies to both sections, so there is no harm done.

ExploreingNC, Is the gauge you used mechanical or electric? Great deal for $16

It's a mechanical guage from Advance Auto

I've had it in for over a week now and I can't keep my eyes off it. It's amazing watching the temp go up and down, it respondes instantly when your pressing on the gas. I didn't relise that the temp fluctuated so much, even when you down shift the temp responds. This was a real good mod, simple and cheep.

I am betting you will see more fluctuation with the sensor mounted in the cooler line than if you were measuring the bulk fluid temperature in the pan. That temperature would change a lot slower (I would think anyway).

I had mine mounted into the pan. It wasn't too bad to do. Just drilled a hole large enough (and in the right spot so it didn't interfere with stuff inside the pan!) to thread in a pipe bushing that would hold the probe end, then I welded it into the pan and sealed it with some silicone, just in case. It lasted through 2 transmissions... (which goes to show that temp isn't the only thing that kills trannys -- mine lost all the springs under the drive clutch plates!) :D

It will read slower, and it will also not show you the temp of the fluid coming out of the front pump and torque converter like a line-mount sensor will.

If I were to do it over again, I'd probably opt for the line mount. For a real killer setup, you could use an electric guage and switch it between two or three probes just to cross-check temps. Be an interesting study at least... See how hot the TQ is compared to the overall temp of the transmission, or the effectiveness of the coolers.

I used a B&M drain plug kit- my electric sensor threaded right in- it does double duty sensor mount and drain plug.

Guys, I installed a B&M unit with a electrical sender and mounted the guage on top of my dash as we out here have rhdrives it's tucked into the rhwindow colomn .I wandered why you changed from the outlet pipe before the radiator because that's where I've put my in line filter .Hot oil flows better but I've put the temp guage on the return and I 've found even towing a 2 ton van the temp hardly gets above 100 degrees F on the return oil but then I've put an extra oil cooler on as well it's certainly a worthwhile mod Cheers Barry

just forgot to mention the bulk of the filter also adds as a cooler and you use extra oil Cheers Barry

If you put the sensor after the coolers then by the time you may notice it overheating then it may be too late. I put it before the cooler so now I know the max temp that I'm getting.

okay, now I understand but if the oil flow back into the tranny is too hot then that to is a worry ???

Here's an alternate way to install a transmission temp gauge (from my registry page, dated 3/21/03 http://www.explorerforum.com/forums/showthread.php?t=73405 ):

After reading of the success of installing an auxilliary transmission filter in this thread: http://www.explorerforum.com/forums/showthread.php?s=&threadid=34136&perpage=20&highlight=Filter&pagenumber=1
I decided it would be a worthwhile mod. I also wanted to add a transmission temperature gauage and needed a place to mount the sender.

I decided on a generic filter mount rather than a kit, so I could fabricate everything just the way I wanted. I ordered the TD products #:TRD-1028 Single PH8A filter housing from Summit for 12.75. I picked up a bunch of brass fittings from Home Depot, and 3/8" hose from Autozone.

I struggled to find the ideal mounting location. I wanted to run a full-height filter, have it vertically oriented, be easy to change and be out of the way of rocks off road. I found the ideal spot to be right behind the passenger side bumper.
http://www.explorerforum.com/data/2/1342212-21-03-aux_tranny_filter_location.jpg

I fabricated from brass fittings the inlet/outlet for the 3/8" hose and the attachment point for the Autometer temp sender.
http://www.explorerforum.com/data/2/1342212-21-03-aux_tranny_filter_housing_and_fittings.jpg

It is plumbed in between the two transmission coolers. The circuit runs from the transmission, into the radiator cooler, out to the filter, to the auxilliary trans cooler, and back to the transmission.

The hose for the filter required relocated the vacuum reserve sphere for the climate system from above the plastic fender lining. Fortunatley, there was plenty of space below the MAC intake, and there were even holes in the sheetmetal!
http://www.explorerforum.com/data/2/1342212-21-03-vaccuum_reserve_relocated.jpg

I was not impressed that ford ran the transmission lines under the already low radiator. I cut them back to above and behind the radiator and ran new rubber hose. The hose will be permanently secured soon, and a skid plate will be installed.

http://www.explorerforum.com/data/2/1342212-21-03-aux_tranny_rubber_lines.jpg

The finished install:
http://www.explorerforum.com/data/2/1342212-21-03-aux_tranny_instal.jpg

http://www.explorerforum.com/data/2/1342212-21-03-aux_tranny_install-final.jpg

The temperature gauge mounted in the center console:
http://www.explorerforum.com/data/2/1342212-21-03-gauges_installed.jpg

After the failure to convert the in-dash oil pressure "gauge," I am putting in an autometer electronic oil pressure gauge.

I removed the complete plastic inner fender this time, not just the rubber "access door." I also removed the low-pressure power steering hose for easier (hah!) access to this cramped location.

I used 1/4" brass pipe to extend the T fitting away from the block to clear the senders. I hooked up the stock 6psi switch in addition to the Autometer sender. I wanted to retain the functionallity of the idiot light/gauge on the dash, and not compromise the accuracy of the Autometer system.

http://www.explorerforum.com/data/2/1342212-21-03-oil_pressure_senders.jpg

Day two consisted of installing the gauge inside the cab. I also installed a transmission temperature gauge at the same time. I wanted the gauges mounted in the center console, I'm not a fan of the A-Pillar as it reduces visibility and could be a potential hazard for my head in a severe crash.

I cut out the bottom "pocket" from the center console, and epoxied in some black plastic.
http://www.explorerforum.com/data/2/1342212-21-03-console_modification.jpg

The gauges were mounted, due to tight clearance issues underneith the console, I had to cut down the Autometer mounting studs and cut the clamp brackets in half. The gauges are secure enough without the clamp, it just adds some rigidity. The +12v, dash lights, and ground come from the radio. All connections are crimped and heat shrunk. Connections in the engine bay for the senders are crimped, soldered, and head shrunk.

http://www.explorerforum.com/data/2/1342212-21-03-gauges_installed_wiring.jpg

Final image:
http://www.explorerforum.com/data/2/1342212-21-03-gauges_installed.jpg

After seeing this again, I remember reading it a while back, very nice work. On my next trans fluid change, I plan to do something similar, though my temp sensor will remain in my pan. Nice work on the gauge install :thumbsup:

After seeing this again, I remember reading it a while back, very nice work. On my next trans fluid change, I plan to do something similar, though my temp sensor will remain in my pan. Nice work on the gauge install :thumbsup:

Thanks Evan!

When I installed my message center, I move the MC buttons to the side of the center console and put my two gauges where the buttons where. I can't find a pic on my computer, but I'll post one.

I don't see much fluctuation at all on my gauge due to it's position in between the coolers.

Just thought I'd say thanks for all the info. It came in very handy when I decided to install the temp sensor and gauge.

here's a pic...
http://img.photobucket.com/albums/v392/CBII/Xplorer/TTgauge_2.jpg