A second hand wire wheel axle was sourced, although the casing needed some attention. Firstly it was very rusty, and secondly, one check strap pin had broken. It was decided to replace both pins with new off the shelf parts. This required grinding off the old pins to a bright smooth finish and then clamping and welding on the new pins with the MIG welder set to a high power for extra weld penetration. The hubs, backplates, drums, and brakes had been removed which also allowed the half shafts to be removed and check for wear.
When attempting the remove the hubs from the axle, it was found that a great amount of force was required to undo the nuts. In the end, the nuts were heated with a propane blow torch until they were nearly glowing, and the hub was held from rotating by using an old leaf spring with the eye around one bolt and the second bolt pressed against it. This gave enough stability to attach the torque wrench (and a six foot extension bar) and release the nut.
With the axle off the car, it was also decided to replace the 'thrust' washers. These sit between the sun gears and the differential. If these washers are worn then there is quite a lot of freeplay in the pinion, causing differential 'clonk' on acceleration which can cause wear on the gears. There are two sets of washers, one fibre and one copper; on removing the old washers from the axle, there was no sign of the fibre washers, and the metal washers were very thin.
With the half shafts removed, it was easier to remove the washers, however only one shaft needs to be removed for this process.
To deal with the rusty case, the differential was taken to be shotblasted, and it came back ready for painting as completely bare metal.
With the differential completely painted and the casing flushed out in case any sand had entered during the sand blasting process, the half shafts were reinserted and new oil seals added.
The backplates (but not drums) had also been shotblasted and were repainted. The brakes and hubs were then assembled using new brakes, springs, slave cylinders, and adjusters.