Been working on the rear differential:  getting the pinion bearing preload right, and getting the backlash on the ring gear within spec.  I need to do a contact pattern test, and then thoroughly clean out everything with kerosene before closing the cover on it.

But first, I built a differential spreader, since it's a pain in the butt to do differential work without one.  (It involves pounding on bearing  cups with a dead blow hammer...)

For scale, the big tubes (2" heavy wall square tubing) are 16" long.  The threaded rod is 3/4".

And here it is, in use: