I searched here and found no threads on this.

Just picked up a 1996 4runner. 135000 miles. One owner. It has a howl or deep whine in the front axle. Cannot find any excess grease or oil on axle where a seal or bearing would be out except where the axles go into the differential. The boots are covered with dirty grease that looks to have been there for awhile. The front end is tight and clean. The noise is worse between 40 and 50 mph. The differential oil is full and clean.

The noise does not change if you turn wheel or slow down or speed up. I am going to swap wheels and tires with another 4runner and see if that changes anything.

Had my mechanic look it over and it has him stumped also.

I have owned a 1997 and 1999 and never run into this with the axles.

 

Solved the noise problem this morning. Swapped front tires with a 1999 4runner and noise went away. Put my tires on the 1999 4runner and noise was there. These tires are the worst. They are Wild Country XTX tires. This set not very good.

Everything cannot be that simple.