One problem related to rear suspension shock absorber has been reported for the 1999 Ford Ranger. The most recently reported issues are listed below.
For the second time as far as I know the rear frame (rear spring shackles and spear tire holder specifically) have and are being replaced because they have rusted and they tore apart. As I was driving I hit a regular bump in the road. I was driving about 35 to 45 mph on the way to work. Well it sounded like it hit pretty hard, as I was driving I noticed the trucks performance was lacking. So, went to work, got out of work and on the way back home I noticed the samething with the performance of the truck. It was lacking in a big way. As I was pulling into the driveway I heard a large clunck sound. The next day I had a prior appointment at my transmission shop. As the mmechanics put it on the lift "the rear axle dropped to the full extent of the shock absorber and busting their seals. Because the shackle broke it was causing the axle to twist while I was driving given the truck the bad performance, bad steering, and giving the transmission a pulsating affect. Also the engine lost the power giving the truck resistance and using more gas. So I am replacing both shackles, both shock absorbers, and the spear tire mechanism. At the same time I will be sanding the frame down, and coating all parts (cleaning and coating parts) with bedliner coating to hopefully stop the rust. The parts that I am replacing are also replacement parts because they are bolted on to the frame instead of riveted like the originals were. Also the steel seams to be thinner in the rear than the front and middle.