The inner and outer graphite impregnated cork seal rings were tapered so in theory you could tap the retainer ring in the back and tighten the seal. In practice you go to a bearing & seal warehouse and find a modern seal to fit the shaft, then machine the case cap to fit the seal. The drive shaft seal is the one that gave us trouble. Reaming out for the seal left little material to support the seal. Some creative welding added strength and sealed the cracks. We were then able to use hypoid gear oil for lubrication. If you don’t do the drive shaft seal, run John Deere Corn Head Grease.
Richard, I think the seal is retained by the outer ring, not the bushing. Remove the outer ring, which Gary refers to as the adjustable component. I’m afraid that you can’t get to the rear of the bushing without removing the retainer and seal. I suspect that the retainer is masked by the scars on the rear of the housing. If I were doing the job, I would create a tool to drive the retainer out from the inside, rather than prying it out from the outside. It’s up to you. Have fun boating! R.T.