Tonight I turned attention back to the differential. With a seized axle in the first diff I purchased, I bought another 3.42 limited slip Getrag. This one arrived with both axles already removed (a good sign!).
Just like the transmission, I want to have solid data on what temperatures the differential is seeing under hard use so that I can determine whether or not coolers will be needed. So, my first step is to add a temperature sensor. I’m again using an Accutech SMI oil temp gauge for this as they are super accurate and affordable.
Drained the diff and then flipped it over and scoped the inside through the drain hole. Turns out there’s a perfect spot for the sensor.
Interestingly, that inner circle corresponds to one of two circles in the outside casting. Red “X” marks the spot for drilling on the rear circle. DON’T mix them up and drill into the forward circle as that will put you right into a partition on the inside:
Once again, drill a pilot then drill out with “O” size bit using grease on the bit to catch shavings. Then tap for 1/8-27 NPT threads. Do this with the diff right-side-up so that any shavings that do end up inside fall towards the drain:
Sensor installed (and after cleaning up the diff housing):
