nice videos , thanks for putting in all that work for those not in the know, a small tip for those that have ball diffs that do not come with that small cover for the adjustment side of the diff is to cut a small bit of fuel tube or even foam from packaging etc and plug the thrust race end of the diff to keep the grime out, be careful not to bind up the diff screw though!
i have been using clear silicone grease for the diff , you can get it at most hardware shops in 100g tubes or 500g tubs , it works just as well as so called specialist diff lube , i am sure its the same damn stuff and costs a few bucks for the 100g tube, i use black molybdenum grease on on my thrust races , again from the local hardware shop and costs only a few bucks for 150g tube , by all means use the AE stuff if you have money to burn but IMO better to save the cash and get some Si3N4(silicone nitride) diff and thrust race balls ,i have had the same ones i got from china 4 years ago via ebay for $12 for 50 !! and have done many rebuilds with the same balls but with new plates etc and the diff's are still silky smooth witheach rebuild .
another tip from back in the day ,to get a tighter diff 'action' without having to over tighten the diff is to leave out 1 in 4 of the diff balls so the diff will have 9 instead of 12 balls, this increases the cm dyne on the diff plates and slows diffs action a touch without risking a blown thrust race.
have fun fella's.