I made this to change lock unit for my Mustang Cobra. I have swapped live axle to independent 2003 Cobra unit. It needed new lock and it must be streched little to get unit out with bearings. Dial indicator tells when needed amount is reached. This was 0.8mm. If you exceed it, case stretches and preload will be too loose.
when fingertight, zero dial indicator. Under adjusting nut must be pressure bearing to make it easier. I found bearing from old car jack.
Image from backside, bolts touch to case inside surface, holes are for bolting it loosely to case.