I have replaced the speedometer cable and gear (20 tooth, black) and the speedometer moves, but not accurately. At about 50 mph it only registers about 25 mph and it moves from 20 to 40 while the truck is moving at a constant speed of about 50 mph. When I feel of the gear inside the transmission it feels concave and the depth of the gear doesn't feel very deep in the center. I think the gear may be slipping / spinning on the transmission gear.

Any suggestions on solving this problem? Anyone know a source for the transmission gear. I understand the part # is C30Z17285C

 

I'm not of any help to you on this subject; but others are; especially if Fordboypete or Banjopicker66 reads your first post. On that note Welcome aboard and I'm sure your questions will be answer. I only seen the speedo dail float back & forth on the round standard bezel's. I always try to spray some white lithium grease into the cable end behind the speedo bezel, I usually get about a 50/50 result of working more accurate.
sorry for weak advice

Mitch

 

Well here s perfect one if the search was working. To bad the brain recall is working just as well. There was a prior post on just this, cant recall the solution but it does seem it was located where the cable enters the tranny. "Replaced" means with new I take it ?

 

dbyrd, Welcome to FTE, The nations #1 Ford truck stop for tech support.
Can you share with us why you were changeing the gear? Did you replace a 20 tooth? If you hold the two gears upright side by side, do the teeth run in the same direction.

The auto tranny used a right hand twist and the manual used a left hand twist, and they can't be swapped.

With a little more info maybe ol Pete or da picker can answer your question.

John

 

Thanks for your reply!

I did a down to the frame restoration on my dad's old 1966 Custom Cab short bed fleetside truck, 240 6 cyl, 3 speed manual about 3 years ago.

The speedometer quit working. When I checked it out, I could turn the cable by hand at the transmission end and the speedometer would move so I decided the gear must be worn out. So I ordered a replacement from Dennis Carpenter. They show the same part number for the speedometer gear for both the 3 speed manual and the automatic. The gear that I received and doesn't work is a right hand twist. I plan to get back with them and see if I can get a left hand twist.

Thanks again for your help!