I am in the middle of a large rear driveline project. So far I've done the outer bearings & seals, new backing plates, new pan & gasket, and will have all new brake hardware. I noticed that the pinion seal appears to have been puking out fluid for a long time and I want to change the seal while I have the shaft off for new u-joints.

I went to measure the existing preload and it is so low, my in/lb torque wrench won't even measure it. Am I suppose to check this with the tires on and parking brake off? Right now there are no wheels on.