Inspect the case and gearshaft housing for cracks or damage of any kind. Cracked or damaged units must be replaced. You will also want to check the case where the bearings insert to see if there is excessive wear. Take a new bearing, insert it into a clean case and see if you can get any side to side movement, if so your case will need to be replaced or some work not covered here. According to Jim Gilmore, a transmission case can be saved by having the case machined and a bushing made to fit the case and the bearing. That should provide you with an idea of how you can save your valuable case.
You can see a video of this by going to Youtube! http://www.youtube.com/watch?v=hF2rwdbB0nQ
If you are going to be working on a T-84 WW2 jeep transmission then you might be interested in my book–Trouble Shooting And Rebuilding The T-84J.
Also check out Military Maintenance for MB/GPW Jeeps 1941-45.