Removing speedometer cable from dash of a 1985 ford f150

unscrew the cable from the transmission. if you can`t unscrew it,unbolt the lock bolt that holds the little bar which keeps the speedometer cable in place and remove the speedometer driven gear assembly from the transmission. the gear is plastic and is what the cable is driven by.

Id say its a loose connection or the meter might need to be replaced.

You can do it one of 3 ways...
a. Remove the Instrument Cluster from in front of the wheel, Lubricate
b. Remove the Cable from Under the dash and Lubricate
c. Remove the Cable from the Transmission and Lubricate.

Removing BOTH ends and cleaning first from Pressure TOP to Transmission is highly recommended and injecting a Light Lithium Grease I have found to give the best results but if you are having a problem with the Speedometer Cable itself... They are inexpensive and easy to replace. That is what I would do if it was making noise.. Less than $30 for a new cable

there is a cable that comes from your transmission to the back of the instrument cluster, in most cases the cable will break, even if you have a digital dash it still uses the cable.

Headlight knobs are attached to a long stem into rueastat switch (dash light dimmer ) push the small button spring loaded of headlight switch behind dash panel. Knob with stem will come out. Careful not to turn on headlights & run battery dead.
Wiper knob has a release tang behind knob push up tang with a small screw driver ( pocket type flat ) or look for a small set screw on knob
Speedometer cable may be broken,loose from dashboard connection,loose from transmission or broken cable gear in trans. Not sure when ford swicthed to magnetic sensors. Possible lost pick up sensor on drive shaft

there is a clip on the back of speedo, you have to push the clip toward the back of the speedo and pull the cable off at the same time.

the front door speaker size is 6.5". i dont belive there is speakers in the dash

Its under the hood drivers side on the upper firewall.

1. Disconnect the battery ground cable.
2. Depending on the year and model remove the wiper/washer and fog lamp switch knob if they will interfere with the headlight switch knob removal. Check the switch body (behind dash, see Step 3) for a release button. Press in on the button and remove the knob and shaft assembly. If not equipped with a release button, a hook tool may be necessary for knob removal.
3. Remove the steering column shrouds and cluster panel finish panel if they interfere with the required clearance for working behind the dash.
4. Unscrew the switch mounting nut from the front of the dash. Remove the switch from the back of the dash and disconnect the wiring harness.
5. Install in reverse order.

Good luck.....

Facing fuse box, left hand side, bottom fuse