Differential Unit problems of the 2000 Ford Explorer

While driving vehicle makes a clanking noise. The vehicle takes up to 2-5 seconds upon changing gears to reverse. Going up hill it will down shift very hard as if the floor board is being knocked out. The differential, and rear end were replaced.

In March of 2004, I took my 2000 Ford Explorer XLT for general service, the mechanic found that the front pinion seal, and torque converter seals leaking. The vehicle was taken to the dealer for repairs. Thank the lord that I took out and extended warranty on the vehicle when I purchased it sept, 2002. The repairs where completed, I also took it back to my mechanic to check and make sure the work was done. On 10/26/04 I took the vehicle back in again for work to be done and the mechanic again found the front pinion to be leaking, also found that the upper and lower ball joints were needed and that the power steering pump was chattering. Just some background information: the vehicle was originally owned by my sister, when I purchased the vechicle, she was turning in her 2 year lease. When I took the vehicle over it only had 11,681 miles on it. The first repairs were at 37126 miles, second time miles were 45721 miles. I also have several area's on the vehicle that have rust. I can remeber a few years ago when the 3 major car companies talked about rust not going to be a problem. One of the places with rust is on the radiator support. I just wonder how Ford or any of our other us car companies can expect us to keep buying inferior products and pay alot more money.

Vehicle has a whining noise from the rear ring and pinion gear between 50 and 60 mph, the ring and pinion gear was replaced but did not correct the problem, now the noise started at 69 mph, dealer tried a number of other fixes but none of them helped. Nlm.