I helped test the original ZF axles for LULL 644E/944E and SkyTrak Legacy series, which was the first applications of the 3045-3060 series. I believe it was derived from a tractor front axle. One thing I will highly recommend is to make sure the lug nuts are kept tight. The cover, which provides the shafts for the planetaries to ride on, is only held relative to the hub through the lug nut clamp load. You will notice 3 small bolts on the cover, they are only there to hold the cover on during shipping and tire replacement. If the lugs loosen up the cover can move around, which obviously isn't good.
We had a 3045, 3060 and 3045HD (I think it was the original 4 planetary 3045, renamed the 3055?). As far as the actual differences between the axles I can't remember anymore. The 3000 series is designed to be modular and ZF can mix-and-match differentials, wheel ends, etc. Initially there was some talk of a lighter version, but with all the problems we had during development it quietly went away, might have ended up on the smaller European telehandlers. Initially foam tires were not approved, but about the time I left is when some of the big customers were demanding it. They are harder on axles due to the higher rotational inertia and reduced bump absorption.
As for other applications they also came on Sky Trak Millenia 4270/4290's (not many were sold), newer JLG's and Deere (not sure of the models, might be 3200/3400?). There are probably others because they are cheaper and smaller than Dana or Spicer axles.
ISZ