VAC 13 ring and pinion

helped a school chum remove the rear axle from his nice VAC-13 wide dash ...this tractor has been in his family for 50 or more yrs and has done very little ,and it looks it , tranny had been locking up, then got to where it would go and then start grinding gears ,,. if we could remove the brake hubs behind the 2and 1/4 bolt head ,. I think we can fix the problem ,.. looks like the entire hub shaft has nearly a half inch of sideways play ,,. you can clearly see the shaft change height from moving on the tapered races as it is shifted back and forth ,.. once we get those whopper bolts out I hope we can draw up the slack,,if that is where it is truly drawed up ??,. cant tell if there is a internal adjustment collar for the bearings . but am wondering ??and THAT IS MY QUESTION.. can anyone tell me.. btw , the pinion by feel seems to be factory true ,,the ring has very little damage to the very leading edge ,there is a few steel granules in the oil,,. I think all will be fine once drawn up ,, nNEXT QUESTION , HOW TITE SHOULD THE BACKLASH BE? .

You make adjustments to the gear mesh using the shims behind the bearing carriers, which are behind the brake drums. The brake drums are, of course, held on by the two 2 1/4" bolts. There bolts are usually glued in place with some type of pipe dope to keep oil out of the brakes (the manual says to apply a sealant for this purpose, avoid Loctite threadlocker). They are not meant to be torqued to a high value even though they are large bolts. There are two adjustments here. The first is end play. Here you adjust the end play on the shaft between 0.001" "tight" and 0.002" of play (the manual actually says "No Play," but this is an accepted standard). Next, you trade shims from one brake cover to the other to move the entire differential assembly left and right to set the backlash. You check backlash by sticking a feeler gage between the meshed gears when the gear teeth are at their closest position. Also, you must set the end play correctly before you can set the backlash. The backlash should be 0.006"-0.008".
Please realize that these are not optional adjustments. If one is incorrect then you must redo (or at least check) both of them. Failure to do so will result in gear-noise/gear-wear problems.
Also, large amounts of side-to-side play in the differential assembly indicate either extreme wear, or missing parts/incorrect reassembly. Make sure that you get a manual and make sure that everything is put together correctly. Also, check the pinion shaft (lower shaft) in the transmission and make sure that its nut is torqued correctly and that its spring washer (at the front end of the shaft) is in good condition. This spring preloads the lower transmission shaft to allow for expansion and contraction of the shaft as the transmission warms up. If there is any "free" end play in the pinion shaft, then you need to adjust it. Also, make sure that the bearings are good. Water can get in through the shifter boot and drip into the transmission in the vicinity of the rear transmission bearings. This can cause both transmission and differential problems.