Hello -

I just bought a 83 F250 with 351 and 3spd automatic. The speedometer doesn't work (needle doesn't move.)

I've never worked on speedometer stuff, so I was wondering where to start?

80skeys

 

The cable runs down and hooks to the tranny(2wd) or the transfer case(4wd). Take the cable off under the truck, and while someone watches the speedo, twirl the end of the cable and see if the speedo moves, and the cable turns freely.

 

I have the same problem with my 84 f250 4wd. I pulled the cable and spun the end and the speedometer moves. Now what?

 

Pull the housing out of the side of the transfer case (or tranny) that the cable screwed to and inspect the plastic gear, it may be stripped. The housing is usually held in with a bolt and a metal clip. If that's ok, then the gear on the output shaft must be missing or has moved, and that's not so easy to fix, but not impossible.

 

Ok, I will try that tomorrow. Thanks!

 

Dave F -

thanks for the tips. I'll check it out this week.

80s

 

The Speedometer cable gear is really easy to change. Just make sure you get one with the same number of teeth, and the same color or it will change the calibration, "speed" of the speedometer.

The speedometer drive gear inside the transmission requires the output shaft to be removed, or the transfere case to be disassembled enough to reach the gear.

Both the cable and drive gears are plastic, and requires you to replace them with the same color, and number of teeth, otherwise it will change the calibration "speed" of the speedometer.

 

Where does the speedometer cable connect to the tranny? I looked around, but all I see are the fluid cooling lines, the dipstick, and the gearshift.

 

Cable should go in towards the upper rear drivers side of the trans. I was just under mine, so that's fresh in my head.....

 

If you can't find it, then that's probably why your speedo doesn't work. It's a large probably 3/8 diameter stiff cable.

 

LOL!!!!!!!!!!

Not trying to be a jerk, it's just a funny comment

 

Turns out it is connected to the transfer case (not the transmission housing). Took it off, rotated it with a drill, no movement on the dash.

Next step?

 

Did you pull the housing out of the transfer case and look at the plastic gear? If not, do that and see if the gear looks ok. If it does, then the other gear on the output shaft may have a problem. You might be able to stick your head up there with a flashlight and take a peak in the hole to see the other gear on the shaft after you pull the speedo gear housing out.

 

Which way did you turn it? If I remember correctly it needs to be spun counter-clockwise (drill in reverse) to advance the speedo. Was there a plastic gear clipped to the end of the cable when you pulled it?

Do you have factory cruise control? If so you probably have two speedometer cables that join at the speed pickup coil of the cruise. It will be near the brake booster. Make sure it's connected all the way through to the speedo. Follow the cable from the firewall to the speedo and see if it's been disconnected. If it's loose behind the dash try snapping it back on to to the back of the speedo. Feel first to see if the inner drive cable comes all the way through. A previous owner may have pulled the short section above the pickup coil if he thought it was noisy.

 

Very good point. There is also another plastic piece that fits into the speedometer head that can snap off. That can be seen with the instrument cluster removed. The instrument cluster should be removed and the speedo cable removed from it's outer housing, inspected and lubricated anyway for routine maitenance.