I think I would short cut all this and just repair the axle. It needs to be done anyway. Having had them break on me I can see how it could be easily confused with a clutch issue, and Bagusjeep has a LSD in the rear.
As the clucth is off it is a good opportunity to inspect it. If the disc and pressure plate are in good condition and the flywheel surface is smooth I would bolt it back on. Sometimes there are issues with the fitting of the release bearing and arm but these can be seen from under the Jeep. I have also seen problems with the linkage which caused slip, my new J20 had a hydraulic clutch whose arm was so long the clutch was permanenetly partly disengaged, slipped uphill.
I suspect that once the shaft is replaced, the whole drivetrain will work again.
BagusJeep lives in Bali.
1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE