recently just bought a 1989 toyota dont think its a 4 runner just a toyota truck but anyways when i have it in 4 wheel it makes a kind of grind noise on the passanger front side every now an then its not constant, then when im going down the highway not in 4 wheel at about 40 it starts to do it again at the same side, you can hear it pretty decent an feel it through the floorboards, i thought maybe it was the front differential or the cv axle but im not sure if someone could help me out with this it would be much appreciated

 

You have the hubs unlocked correct?

I would bet that brass spindle bushing.

 

could be bad bearings. i had a samurai do the same thing and it ended up being realy realy bad bearings. easy fix though so thats good. if the hubs are unlocked then you can be pretty sure its not the cv's or the diff.

 

+1 on the bad bearing. I had a very similar issue. Bearing was shot.

 

but it doesnt sound like a bad bearing the sound isnt constant an it doesnt sound like a rub its more like a gear grinding for a moment then it stops then it will happen again shortly

 

Do you have manual hubs? Are they locked when you are in 2wd? Unlock them in 2wd and see if it squeels.

 

i unlocked my hubs an it still goes into 4 wheel when i pull the shifter into 4 wheel lol and i dont think it grinds when they're unlocked but i always thought to have a truck go into 4 wheel they hubs had to be locked

 

The hubs lock the tire to the axle. When you put the transfercase into 4wheel drive it will turn the axles wether they are locked to the tires or not. So if you have the hubs locked but you are ony in two wheel drive the tires will turn the axles.
If it doesnt grind when the hubs are unlucked it could be the cv's or the ring and pinion. However a bad bearing would cause a random grinding noise.

 

Most likely a bearing, I would say form what you are describing.