2004 Mercury Mountaineer has hub bearing defects, transmission defects, drive train defects, rear axle and differential defects. There are thousands of complaints about these components of Mercury Mountaineer and Ford Explorer yet NHTSA does nothing. Ford will not fix these problems and has been doing band aid fixes under warranty. They deny there is a problem yet there are thousands of complaints on the various web sites. It makes me believe NHTSA is in bed with the auto manufacturers and really don't care about the public. Wheels fall off cars cause hub bearings fail yet there is no recall.. Ford puts the wrong transmission fluid in cars, transmission fails...there is no recall. Rear axle seal fails and no recalls why!!!

- Akron, OH, USA

Rear axle failure at 35,000 miles. Replaced both rear axle shafts, bearings, seals, cv boots, and complete differential with used parts per the extended warranty coverage.

- Milwaukee, WI, USA

We put two new tires on the front of the vehicle in July 2006 on our 2004 Mercury Mountaineer AWD. In Dec 2006 we took the vehicle into the dealer South hills Lincoln Mercury for a transmission problem and state and emission inspection. The dealer fixed problem with transmission, and did inspections. Then two weeks later, on new years eve, we broke down. Vehicle was towed to nearest Ford dealer in bedford, pa. The bedford dealer said due to the different "circumference" of the new tires on the front and the older tires in the rear it ruined the differential and transfer case on the highway. Our manual states nothing about this only says to put on the same style and type of tire which we did. They said the circumferences of the tires can not be more than 1/4" different. The factory rep says if we would have taken the car to the dealer for tires they would have told us this. They are blaming the tire dealer for not knowing this tolerance. The tire dealer says 1/4" tolerance is ridiculous. The cost of the repairs and rental car is over $5000 South hills Lincoln Mercury in pittsburgh was going to honor the warranty secretly for me, because they sympathized with my problem and I think the service mgr there knows Ford has a bad engineering drivetrain. However bedford Ford notified the Ford factory rep and now South hills Mercury is backing out of honoring warranty. My complaints are: Why doesn't the manual state anything about the tire circumferences" is this really the cause? 1/4" tolerance is way to small in the engineering of the drivetrain? - if one tire gets damaged after 10,000 miles you have to replace all four tires I guess? why was one dealer going to honor warranty and the other not? why didn't the dealer notice this problem when they inspected the car and worked on the transmission problem" part of the inspection process is to measure tread depth. If there was a big difference shouldn't that have been a red flag.

- Pittsburgh, PA, USA