3rd Gen rubbing noise

[langtounboy]

I've searched all through the forums and can't find an answer.
I left the truck parked up for 4 months when I was working over sea's.
When I returned there was a rubbing noise that increased with speed coming from the front. I could feel the slight vibrations through my feet but there is no vibration through the steering.
It's passed an MOT and I asked for them to check for cause but nothing found.
Another mechanic said it was my diff but looking at these forums the diff sounds different.
I've changed the diff and transfer box oil but no change. There was some grey sludge on the mag plugs but no metal fragments.

Any ideas?

[will.b]

Possible stuck brake caliper

As per title, jack up front wheels and spin, see if you can hear anything rubbing. It might need new calipers or with a bit of gentle manipulation, squirt some brake fluid around the seals, and see if that frees it up.

[Dobbslc]

Drive shaft gaters? Mine rub and squeak when turning.