You probably have grooves worn in the output shafts. They pop right out if you want to take a look. Changing to new seals may actually cause a leak, since the old seals were worn into that groove. I imagine a decent machine shop can stick some of those SS sleeves on the shafts.
When I did mine, I had to hunt around to find a set of shafts that were not grooved real bad.
When I did mine, I had to hunt around to find a set of shafts that were not grooved real bad.