1953 M38A1 differential setup

[51 CJ3]

Then my question remains unanswered. If I have this correct, you are creating drag by using a wedge or light application of the brakes to check how the teeth interact. How are you putting a load to the teeth? Using a wrench on the pinion nut? Connecting the drive shaft and turning it with the engine? Using a drill or impact? Screwdriver through the u-joint u-bolts? Pipe wrench on the output shaft? Like I said, I have not worked a differential before. I have lots of other maintenance experience but most of it is in aviation, some boat and tractor. Overhauled a transmission on a ‘66 CJ5 and did a transfer case conversion on a ‘74 Cherokee about 30 years ago. I hauled a couple of axle assemblies to a shop to have work done but this is the first I have attempted myself.