Two suggestions for you.
1) This is likely a Lippert 3.5k axle or possibly a Dexter. You may be able to identify it from closely inspecting the axle tube. Might find a part number.
2) Easiest way to identify the bearing(s) is to pull the hub. Clean them off to see part number. The example would be 25580 (not manufacturer specific), this number is not for your axle.
If they are in good shape repack grease. I do suggest a new grease seal. While you got hub off you can inspect brakes as well.
I would agree with previous post not recommending use of bearing buddy.
Doug & Tiffany
2016 F-350 Platinum DRW
2010 Harley Davidson FLHTK (Ultra Limited)
2015 Voltage 3605