2000 Mercury Mountaineer Question: Grinding When Turning Left or Right

Can you tell if the noise is coming from the front or rear of your Mountaineer?
You hear this turning a corner, like a slow u-turn or left/right-hand turn? Does it do this every time to round a corner? By any chance are you holding the steering wheel at full left or right (against the stops)? Most or all steering systems do make a noise when the steering is held at the stops but I want to make sure you're not referring to this condition

I believe your transfer case is going bad (the chain inside the case is overstretched and it makes a grinding noise ) Double check your transfer case fluid level and here's a site that you can call for help http://www.santaclaratruckwreckers.com/ these guys have rebuilt a couple of my transfer cases and rear ends and they are quite helpful in diagnosing problems over the phone

I have a 2002 Mountaineer. If the noise occurs when you are starting up from a stop position and turning left or right, then this is a known problem from Ford for this era of Mountaineers and Explorers. The problem is in the rear differential and must be repaired at a dealersip. There is a Ford service bulletin on it. Has something to do with the gears in the differential. I've had mine fixed twice in the four years I've owned the vehicle, and it's doing it again, so I'm not very happy.

probably lower or upper ball joint. my lower is going bad now. sounds horrible

it is your hubs where the bearings are 149.00 napa but you must change boath

I literally got my 2002 MM back from the mechanic today and it was the transfer case. About 9 months ago same problem and I took to dealership since it was still under warranty. Two weeks and $3500 later they 'fixed' the rear differential. I had taken it to them this time and it was the front differential. Their estimate was $2100. I took to a friend who diagnosed the TC and did the job (among other things) for $950 and it runs great. Mechanics are like doctors, get a second oppinion!

differential transmission

It could be the transfer case as someone mentioned here, or the rear clutches could be binding up. Sometimes a fluid change will solve the problem, Ford makes something called a friction modifier for rear differentials. This combined with synthetic gear oil could fix the issue. Also, I would service the transfer case as well and see if this helps. The transfer case simply takes transmission fluid, dexron 3.

I had this problem exactly as you describe it. I took it to three different mechanics and they all said the same thing; faulty upper and lower ball joint. The quoted me a price range from $600 to $750. So I let a mechanic I personally know fix it. First he asked me if the noise lessened after a soaking rain and I said yes. So he thoroughly lubricated the ball joints. He pushed down on the left front end of the car (where the noise was). There was not any noise at all. He took the swing arm assembly part off and showed me the problem. He moved it around and the noise was there. Well we went to the auto parts store and bought the part for $108 and he installed it. He charged me $100 for labor. Yay! No more grinding noise that causes people to stop in their tracks and stare. So check it out but do your research for the best possible cost first.