67 F100 Speedometer/Odometer Issues

[KStew67F100]

Within in the past 50 miles of driving my 67 F100 I noticed that the speedometer just swings back and forth across the gauge (all the way from left to right). At the same time that started, the odometer stopped turning. I'm assuming these two issues are related. My first thought is that the speedometer cable is loose, but I haven't had a chance to take a look at it yet. Before I do that, has anyone dealt with this issue before and can give advice or instruction? Thanks!

[Whateverman]

is it noisy? if so you most likely need to lube the cable ,unscrew it from the back of the cluster (its alot easier if you unscrew the the cluster so you can pull it out towards the steering wheel) and pull the cable out of the casing ,i wipe some wheel bearing grease on it before sliding it back into the casing,others prefer fancier stuff but hey whatever floats yer boat

if that doesn't fix it crawl under the truck and check the cable to make sure it isn't damaged , and depending on which trans you have also check the drive gear on the end of the cable for wear or damage (c6 trannys tend to have a thread on speedo cable unlike most manuals and all the c4's i've come across)

[mmerlinn]

The symptoms you describe seem to point to an apple-cored speedometer gear. Pull it out of the transmission and check it.

[KStew67F100]

Thank you all for your help and replies. Well I put on a new speedometer cable, which ended up being the wrong cable (was round, which the one I need is square). From there I decided to put the old speedometer cable back on and check the speedometer gear. The guy I bought the truck from had rebuilt the transmission and put on a 2600 torque converter, so the speedometer gear looked to be almost brand new. I hooked everything back up and the speedometer/odometer worked perfectly. Maybe the cable just slipped out or binded up, but that's the best outcome I could hope for.

[colnago]

Interesting. I had the same thing happen, but it was at the speedometer end of things. The speedo needle started going whack-whack-whack from side to side, although it settled out when I got above ~30 MPH. I also had the odometer stop working. I ended up putting in an instrument cluster from an F-600, and was back in business again. Sounds like your problem was at the tranny end of things, though. Glad you fixed it!

Joseph