Jim Grant's Tech Tips
'95 Ford Aerostar, Rear End Noise
looking at a 95 Ford Aerostar extended that has a noise in the rear
end that my short wheel base Aerostar doesnt have. It sounds like
snow tires humming (not very loud) and it only occurs during acceleration.
all you should do is look at that vehicle and walk away. Why? The noise
youre describing is that of a failing pinion bearing in the rear
end. The concern is how long has the vehicle been driven with this condition?
As a bearing fails little metal flakes break way. These flakes become
suspended in the fluid that cools and lubricates all the other bearings
in the rear end/differential. It is a rare day that one failing bearing
doesnt begin the failure of others or worse yet damage the differential
ring and pinion gears. To correctly repair this condition the rear end
should be fully disassembled, cleaned and inspected. Sometimes its
easy to replace just the loud bearing. But if the job is not done correctly
youll have a chorus of bearings singing their way into your checkbook
sometime down the road.