Subject, 1986 4Runner

I go and lock my hubs(ASIAN)yesterday and I get this howling noise coming from the drivers side after a half mile of driving with some resistance.

I was still in 2wd.
UNlock the hub and the noise goes away...
LOCK the hub and the noise comes back after a few seconds.

I go home and jack up the front and see if I could find an obvious problem.

The wheels and axles turn as they should.
Hub dial turns fine from lock to free.
I pull the hub and find a little rust, so I clean the hub, add new grease and reassemble.
Problem noise still there.

2wd or 4wd with the drivers side hub locked I get the noise.

The wheel bearings seem fine, no bind in the wheel.
The noise sounds like a locked up wheel bearing?

...any insight?

Thanks