I have a 91 ford explorer 4x4. I have a loud grinding noise coming from passenger side front wheel that started a few days ago. I have been told cv joint by one person, wheel bearing by another and I dunno by yet another, all 3 mechanics. HELP

Your wheel bearings need replaced,just replaced both front ones on my car,Then you will need to have your tires balanced,rotated and front end aligned.Mine was coming from my front driver side,it was loud,replaced,then the passenger side was making a noise,but not as loud,now it is like new.

Have the cv joints professionally checked if the noise happens while moving

Sounds like you have either ball joint issues, or problems with the CV joints. The other possibility is a problem in the transfer case causing the front axle to bind. You can physically look at the CV joint boots to see if they are torn open and many times you can grab onto the axle and give it a good tug to see if it will move..it should not.

replace wheel bearings or check for feathering of tires

If the bearing was bad or he did a bad job, then the wheel should be lose and you would feel it shimmy or vibrate.

If he is very careful he can jack up the car so that tire comes off the ground, then try and move the wheel from side to side, top and bottom play and in and out, there should not be any looseness or play. If there is this might be the problem.

But if not, then it's the CV. A grinding noise while turning is almost 95 percent a CV joint problem.

When you turn and hear a noise it is usually a CV Joint that is going bad. Humming can be a lot of things. Tires wheel bearings, rear end differential etc.

4x4 ? how many miles ? jack front wheels off ground and rotate by hand feel for the grind, bad wheel hub bearing? check brake rotor dust shields, If high miles possibly front carrier or pinion bearing. Just replaced front , rear , and transfercase bearings on my 98 with 193,000 mi. And yes,they were all bad $500.00 did labor myself. did rear first as it was humming, week later grind and hum coming from front, then couple days later transfer case was also whinning,humming, good god what a project all that was but today its great and quiet.

It could be almost anything, but it sounds like you may have lost a front cv joint. Jack the front of the car up and put jack stands under it, and reach in and try wiggling the shaft that comes out of the transmission, one on each side, and goes to the center of each front wheel hub. If you can move one at all other than turning it, it will need to be replaced.

I say it's the CV joints. You have to jack up under the lower A-Arm, to take the spring pressure off of it, to check them.

(Use jack stands, and wheel chocks behind the rear tires. Emergency brake On. Work on a hard level surface. Be SAFE! Trucks can be replaced, YOU cannot!)

BY THE SOUNDS OF IT ONE OF YOUR WHEEL BEARINGS HAS GONE BAD. WHAT I WOULD DO IS JACK UP THE FRONT END AND CHECK FOR PLAY IN THE WHEELS MOVE BACK AND FORTH TOP TO BOTTOM SIDE TO SIDE. CHANCES ARE YOU WILL FIND ONE OF THOSE WHEELS HAS ALOT OF PLAY IN IT. IF THAT IS THE CASE YOU WILL WANT TO REPLACE THE INNER AND OUTTER WHEEL BEARING AND THE WHEEL SEAL. TRY THAT GOOD LUCK AND HOPETHIS HELPED.