Speedometer not working

Hey guys, I have a 2001 F250 7.3/auto 2WD.

A couple weeks ago I drove through some deep water after a heavy rain.
By deep, I mean maybe up to the center line of the hubs.

The next day the speedo needle was bouncing like crazy and then stopped working altogether. ...and the O/D light started blinking.
Got a P0500 code.

Changed out the the speed sensors on the 3rd member, tail end of the trans, and both front ABS sensors.
Also changed the connector on the rear-end VSS

Speedo still doesn't work, O/D light still flashing and no cruise.
All the other gauges work fine.

Any suggestions?
Could the erratic, bouncing speedo have "burned out"?

Thanks for the help, Boogie.