D350 Transmission Cooler and Gauge
I decided to add an additional transmission cooler and temperature guage so we could monitor transmission temperatures when towing. Since the 46rh transmission doesn’t have lockup, it’s recommended that an additional cooler unit be added. The original transmission cooler is still in place above it, I just added the additional one below it ( the one on the right ). You’ll also see that I replaced the existing A/C condenser with a 20 x 14 parallel flow unit. This is explained in the A/C retrofit.
Here is where we added a sensor bung to the pan ( advised by my transmission guru as best option for temp monitoring ) and a 1/8 – 27 NPT thread tapped into the bung for the sensor. You’ll use a 11/32 bit and 1/8 -27 tap ( available from Oreilly ) to tap into the bung. I do have a welder, but the metal is too thin for my MIG, so I decided to have my A/C guru do the weld on the bung instead. I do have a lathe, which allowed me to spin the metal piece to the size I wanted. You can just use a 1/4″ steel spacer for this and tap and weld it to the pan and you’ll get the same result. You will want to make sure the sensor is somewhere on the side of the pan where it won’t interfere with any of the internals of the transmission.
I mounted the gauge ( ordered online ). This unit has colors that can be selected with a button at the bottom of the gauge as seen below ( looks cool ). It has wiring for switched DC plus Battery+ and lights so that when lights are turned on, the display lighting will dim by 30 percent.
As seen at night