Hi, Bill
I'm not familiar with the Athearn wheelsets you mention. I have used the Athearn 60024 gear to replace the geep series cracked gears by pressing the original axle stubs into the new gear.
IMG_0128_fix by Edmund, on Flickr
If you have the early E units with the separate journal box, the axle has a small pin sticking out to engage the journal. Later Walthers trucks do not have this pin as the journals are part of the side frame.
The PA has a completely different gear assembly. I have been fortunate in that I've never had to replace any of the gears in my Es or PAs if I recall.
This is the Walthers replacement for the "Geep" series:
https://www.walthers.com/replacement-geared-driver-assembly-diesel-wheelset-pkg-2-for-early-proto-2000-r-bl-fa-gp7-9-18-20-30-60-proto-1000-tm-f3
This is the one for the "early" E series:
https://www.walthers.com/replacement-geared-diesel-wheelsets-fits-early-proto-2000-r-e6-7-8-9-pkg-3?ref=1
Good Luck, Ed