Originally Posted by Scottina06
thats a QD2 sensor bro
Eh? QD2 works off the wheel speed sensors. I doubt there are any QD2 sensors on top of the diff itself and I bet what the OP is talking about is a TPMS sensor 'cause I have an '08 Limited (with QD2) which doesn't have a pressure monitor for the spare (and also has no sensor on top of the rear diff).
To the OP - did you ever consider pushing FixAFlat through one of your previous attempts to seal up the leaks? You'd probably have to put a regular valve in first, then replace it with your TPMS valve after the FixAFlat was in.
Now that I think about it, FixAFlat is probably viscous, so it might muck up the sensor even if you waited to install the sensor until after the FixAFlat was pushed in.