AMC20 axles always seem to get the undeserving bad rap. In it's stock form it's at it's worst, but will hold it's own unless it's being thrashed, which it wasn't intended for. The axles has 3 weak points and the one is where it gets it's bad rap from. The infamous 2 piece axles which has the hub keywayed and splined to the axle shaft. These are shallow splines and once the key shears the splines aren't much help. This major flaw in design is easily overcome by a quality set of 1 piece axles such as ones by Moser Engineering.
The second weak spot, though not near as common unless v8's come into play, is that the axle tubes are press fit into the center section and given a quick spot weld. These can break free and allow the center section to spin upwards. This can be overcome by adding some welds around that intersection. Three 1 1/2" long welds will do the trick.
The third is the thin walled axles tubes. This issue is even less common unless your jumping your Jeep or heavily hopping it to get over an obstacle. A truss welded to the tubes will overcome this issue.
With those issues being addressed, it's been said this axle is on par with a stock
Dana 44 but the 20 has a stronger (larger) ring and pinion gear. So addressing these 3 issues isn't too difficult and is much cheaper than swapping out the whole axles. For the average Jeeper, replacing those 2 piece axles will get you through most anything. Sure, there are stronger axles out there, but most probably don't need them. I'll be replacing my front
Dana 30 before replacing my rear modified
AMC20 .