The PSOM has nothing to do with the Transmission at all in a 1994 F53.
The PSOM in the 1994 F53 does not send out any information.
So fuse 8 or 18 would not cause your Transmission problem.
If the VSS signal from the VSS is shorted by the PSOM it may cause it but very unlikely.
You may have a bad VSS drive gear.