Dana 300 Rebuild Home

Disclaimer: The information provided here is how I did it. I strongly urge you to do your own research and make sure you do it right. No claim is made that the information provided is the only way it should be done, or that you should follow my work without verifying for yourself that it is correct. You are free to do as you choose with the information shared here, but you do so at your own risk.

The trigger was pulled on the JB Conversions 2307 LoMax 4:1 gear set. This section of the website will detail the overhaul and upgrading of the Dana 300 transfer case that was in the CJ7. The plan of attack is as follows: 1.Install the new gearset and rebuild the base unit. 2.Install an Advance Adapters 50-3032A heavy duty rear output shaft kit. 3.Install a JB Conversions 15-1103-1983 heavy duty front output shaft kit. 4.Install a Northwest Fab TCB08-4000-K billet aluminum inspection cover. 5. Install a High Angle Driveline Transfer Case Brake.

Figure 001
Figure 001

Figure 001. The LoMax gearset came in, and they are a real work of art. The instruction book is detailed with pictures and looks like it is thorough for the installation. This photo is inside the box as it came from JB Conversions. You can see those are some beefy teeth.

Figure 002
Figure 002

Figure 002. Here is the dana 300 as it came out of the jeep. It is pretty dirty and obviously has had some leaks going on. We will fix that with the rebuild and it will be better than it was new.

Figure 3
Figure 003

Figure 003. Here we have drained the fluid and removed the cover. We have also removed the rear output assembly. It will be discarded as we are going to replace it with a heavy-duty unit. This case has not been rebuilt before, and the output assembly did not come out easy.

Figure 4
Figure 004

Figure 004. The next step is to remove the intermediate gear shaft. Remove the bolt and retainer. We tried to drive it out with a punch and hammer but it would not move. Some more research is in order.