Have a Dana 300 with a bad leak. I had the lower seal replaced but it seems it is still leaking from the center piece (indicated by arrow). I'm wondering how hard it would be to tear this down by myself and re-do all seals? Any thoughts or write-ups that come to mind?
Remove the case and if all you have to do is seals pretty straightforward.
Clean the exterior with a degreaser, wire brush and green scrubbers.
Get a seal remover tool NAPA $8. Use it to remove the seals and compare each one to the new ones to make sure they are correct.
Grease the shaft the new seal goes over or when you reinstall the yokes. Carefully install the new seals.
I start with a small ballpeen hammer and tap it around to get it started and finish driving the seal into the case with a socket. Most of those will be from a 3/4 drive set. If none available continue carefully using the hammer.
If you need to split the case you really need to find at least an exploded parts diagram, or the manual.
Fortunately we run 231s and they are very simple. Hope that helps.