1999 Ford Ranger squeals

Camshaft Synchronizer assembly.
If you are hearing a squeal, almost like a fan belt squeal, that seems to be at bottom end of motor into transmission. I have ran across this with several Ranger's and even had our local Ford dealership send thier Ranger's with this problem.
The Synchronizer assembly is on the passenger side, rear of engine next to firewall mounted behind rear intake manifold. The camshaft sensor mounts on top of the synchronizer so that's all you can see is the camshaft sensor.
When motor is cold and noise is heard, feel the top of the camshaft sensor, you should feel the vibration from the noise. Or, better yet use a stethoscope if you have one.
I have not found bearing's to rebuild the synchronizer so if this is your problem you are going to just have to replace it with a new one. You are looking around from $130-$200 for a new one.

Camshaft sensor

Camshaft Synchronizer Assembly

Hope this help's, good luck