Installing a Transmission Temperature Gauge in your Jeep

[TerryMason]

Personally, I enjoy my automatic transmission - It's nice around town, and is great for offroading, allowing me to focus on my lines, and where I'm going, instead of worrying about my clutch burning out, or engine stalling. While autos aren't for everyone, they definitely have their fans (me among them).

One of the biggest problems with an automatic in a Jeep is that the low speeds you see in rock crawling cause less airflow, making the transmission heat up quickly. Heat is the main reason that transmissions die, and once you cook your transmission your looking at some costly repairs. The sad part is that this is a pretty easily avoidable situation - if you simply knew when your transmission was overheating, you could let your Jeep cool down. That's where the transmission temp gauge comes in.

After some research, I decided to pickup a digital temp gauge, along with a sender (the sender gets mounted in the transmission pan). I picked the Cyberdyne Blue Ice Digital Gauge (part number A221E351Y) from Jegs. At around $80 it wasn't the cheapest, but it looked nice so I went with it.

[TerryMason]

The sensor needs to be welded into your transmission pan - well, more accurately, you weld in what's called a bung (this is like a nut, and has a threaded inside). A hole is drilled in the transmission pan, the bung is then welded over that hole, so that you have a spot where you can screw a sensor (looks like a bolt) into the transmission pan.

The thought of drilling and welding my only transmission pan made me nervous. I was able to pick up a new pan off of ebay for only $45, so I went with that. I took it to my local metal shop, and had them weld on the bung.

Here are some shots of the new Wrangler transmission pan

[TerryMason]

I removed the old transmission pan and installed the new one - changing the fluid and filter along the way (take a look at my Wrangler fluid change article here: http://www.jeepz.com/forum/drivetrai...er-change.html (Jeep Wrangler automatic transmission fluid and filter change) ), After the new pan was in place, I pried up my center console and ran some wires through the console area under the Jeep).

Here are shots of the center console popped up with wires (through a grommet) to the underside of the Jeep.

[TerryMason]

Next I climbed under the Jeep and wired up the sensor. You'll want to wrap the wire in some heat insulating material - I slid on some high temp vacuum line that protects the line from heat.

[TerryMason]

Next I prepped the console in order to drill the gauge hole. I used a hole saw (a large drill bit designed to make holes) for the mounting hole, but before drilling, I taped over the area. This helps prevent extra knicks and marks.

[TerryMason]

I was able to power the gauge using the power that was already run to the shifter - this includes a headlight wire (to dim the gauge when the headlights are one). I then mounted the gauge.

[PinCushion]

with my current issues with my transmission and needing to drain the pan anyway, id like to do something similar to this.

can you use the temperature hole as a drain hole too?

[TerryMason]

with my current issues with my transmission and needing to drain the pan anyway, id like to do something similar to this.

can you use the temperature hole as a drain hole too?

Sure, you could take the probe in and out as a plug, but if that was your intention, I'd just weld in two bungs (holes with plugs) when you were installing it - one for the sender, and another as a drain.