Forward drive shaft is removed from (4x4) transfer case & forward differential
The rubber boot from the spline connection had split open and all the grease had leaked out. A temporary quick fix was made by wrapping the old split boot with electrical tape
the old boot is removed and the spline separated from the main shaft
the spline is cleaned
new rubber boot installed
the drive shaft is reconnected via the spline and new water proof grease is applied via the greasing access point of the shaft