94 Pathy front end squeal

[jpratt2]

My 94 Pathfinder 4x4 recently developed a high-pitched front end squeal...definitely metal-on-metal, that seemed to be coming from the left front wheel. This came on suddenly on a straight stretch of road and was not related to engine speed, braking or being in/out of gear. Also no vibration.

I immediately pulled over, and as I coasted to a stop the noise slowly faded...totally related to wheel movement. Once I started again it wasn't there but came back a few minutes later. I stopped again and the wheel cap felt hot so I let it cool a bit before proceeding home. It did it once more, seemingly after it had time to warm up.

I immediately thought wheel bearings and/or brakes. I pulled the wheel and measured rotational force to spin the disc at 40lbs.with caliper in place. Without caliper it was within specs of 2-4 lbs.

Brakes look fine...plenty of pad left, disc is smooth and well within specs. Caliper came off with no undo effort.
I next removed the disc and hub from the spindle. The two wheel bearings looked and felt smooth with no signs of scoring or discoloration. Still grease in there too.

I removed the steering knuckle as the CV boot was torn. The needle bearings in the knuckle looked ok but there did seem to be some play there.

So the questions are what to replace. The Pathy has about 150,000 on the odometer, all pretty gentle miles.
Replacement Options:
1) wheel bearings only
2) steering knuckle with needle bearings (I guess its pretty difficult to replace the bearings in these)
3) definitely the CV boot
4) possibly the axle shaft assembly?

I feel like I'm shooting in the dark here so any suggestions are more than welcome!