It’s probably bearings, I did mine and it’s not as simple as it seems, removing the sideshafts can be a nightmare, took me approx 4 days with special tooling I made to loosen one, the other took 20 minutes.. then you need tooling to remove the entire knuckle assembly from the various control arms, and you absolutely need a press to push the old bearing out, and the new one in. Holding the knuckle in place on the press can be beyond frustrating. I am fortunate enough to have a lathe and mill in the garage so I was able to machine correct spacers and adaptors to make the job less frustrating, and even then is was a chore.
I live in a very dry climate, you would be amazed at how good my 2011 fatty looks on the underside thanks to little humidity and no salt on the roads in winter, and still I battled like a dog to pull things apart, can’t even begin to imagine what it must be like on a vehicle exposed to high humidity..
You also need the mother of all torque wrenches to tighten the sideshaft nut to spec once done..
I do have a write up in a local 4x4 forum with a good few pics, link below if anyone is interested in pictures of some oil and a dirty garage...