Normal wear/failure of that transmission WILL be the forward cluster bearing as the power flow goes through the input shaft, and then to the cluster gear in all gears except 4th.
Oddly enough, the 4-cylinder uses a tapered roller bearing in this position for a greater load carring ability, but the "larger, stronger" V-6 trans doesn't.
It doesn't appear that there is a method to control the preload of the bearing, so that a tapered roller could replace the ball bearing either.
The bearing removal method that I described as never let me down.
Kary

1987 Mitsubishi Pajero "Modified"
The other original Mitsu brother
Northwest Trailmaster