Outer Limits 4x4 Board

got a 84 4runner that seems to get a bad bearing/grinding noise in the front end after a while of 4wdriving but it will only start at high speed but then wont go away but once the car has sat for a day or two its gone and takes more then half an hours driving to come back and it went dosnt make it when the front diffs not turning any ideas would be great cause i dont really want to pull the front end apart

Did you check the front shaft??
I had a horrible noise coming from the front end somewhere, I thought it was coming in the front diff, turns out it was the uni joint on the rear of the front shaft(double cardan??), it had heaps of play, I replaced it and its been good since.

Yeah I have a different front shaft and different transfer and it still happens. Going to pull it down a bit today

I'd be looking at the CVs

Why are you driving at high speeds in 4x4
84 runner is it the live axle model or independant front end.
try isolating the issue, remove the front driveshaft and drive it....., then lock the hubs in and drive it..... is noise still there.... start with stripping the hubs and checking wheel bearings and stub bearings....
The first thing i would be checking DO YOU HAVE OIL IN THE DIFF...... might sound stupid but its and old truck and most people dont check front and rear diff oil...

Yeah solid axle and is full of oil. Only hits high speeds on the beach or inbetween tracks. The issue with isolating it is getting it to make the noise. Slid the axles in and out and the drivers side makes a different noise when it hits the outer end so will strip that side today