Front end noise?

I recently purchased a 2001 xj with a 3 inch skyjacker lift and a jks adjustable track bar. Yesterday it started making a noise in the front driver side area. It sounds like somethings loose but from the limited time I had to check it out everything seems tight enough. The noise is worse over 40MPH and almost constant at that speed and faster. If i hold the steering wheel to the right a little bit the sound goes away, But if I turn to the left a bit it seems like its worse.

Any ideas? the only thing I can think is the U joint in the axle?

Thanks

Jack your left front wheel up and check your unit bearing (hub) on that side. Then do the same on the right.

how hard are unit bearings to replace? whats a good brand to get? are ones with grease zerks better? and how often should they be replaced? i have a 2000 with about 120K on it. it seems like only in 4 low it makes a noise "sometimes" like... ur rolling over rocks with a pipe on say cement, i cant say its loud but its just a sound i notice that i think it relates to... it doesnt sound like the once in a while gear grinding noise i get when going from 4 hi to 4 low... its just different. any ideas? most of the time i hear it when im at full lock or close to it driving in reverse or forward in 4 low at a slow speed like trying to make a slow tight turn.

I prefer Timken bearings. I run them for everything on my axles.