You should be able to. We swap pinion yokes all the time with no issue.Breather isn't clogged or crimped. I can def see the fluid leak around the pinion. So, I'll be changing that out. Can I just take the pinion nut off, remove and replace the seal, then reinstall and retorque the pinion nut? I've done all my own suspension, brake and engine work. However, have never done any diff work. It's an RJ60. I guess I'll be doing some research on RJ60 assemblies. Thanks for your help.