I picked up the 8.8 31-spline axle (code V313L) for $150 and it seems to be in good shape. It's not bent, there are no broken teeth, the pinion flange only rotates (no in/out/side movement), and everything rotates smoothly. All that I've done so far is drain the gear oil and remove the drum brakes, but I'd like to replace the axle shaft seals and bearings, replace the drums with disc brakes, replace the brake lines (some are pinched/compressed), and possibly replace the pinion bearing and seals. I've watched some videos on how to change the 8.8 axle bearings and seals, but none of them have the same internals as my differential (there is no cylindrical cross pin to remove after removing the cross pin bolt in my differential). I'm also a first-time mechanic so all of this work will be brand new to me.
1. How do I remove the axles to change the shaft bearings and seals, since there is no cylindrical cross pin to slide out after removing the bolt?
2. Is it worth trying to replace pinion bearing and seals, or should I just leave it alone?
3. Is it worth trying to change the brakes from drum to disc?
4. When refilling the differential, can I pour the gear oil directly into the uncovered differential and then just replace the cover, or do I need to first replace the cover and only fill it from the fill plug?