Front wheel bearings on a 4 wheel drive Explorer are not serviceable, replace them.
the galexy does not weigh anything its mass is around 1,153,678000000000000000000000000000000000000 kg
It would weigh same as it would weigh at zero speed, providing you are not nearing the speed of light.
On a 1993 Ford Explorer : None , unless it has been converted from R12
Curb weight is 3879 lbs.
My 1995 Ford Explorer XLT , 4x4 , automatic had a shipping weight of 4,053 pounds
It weighs 4,657 lbs.