How do I know if my front differential is out?
The front differential has a purpose to propel the front wheels, in turn giving your Mercury its 4 wheel drive capability. If you are experiencing abnormal rotational sounds or a clunking or banging during acceleration or deceleration while the 4 wheel drive is engaged, you may indeed have differential problems. Since you suspect your front differential is out, I would recommend enlisting the assistance of a certified mechanic, such as one from YourMechanic, to come by and test drive your Mountaineer. They will have the experience and trained ear to quickly determine if you are having front differential problems.