I have a '65 F100 2WD SB with a 3-speed column shift manual transmission. I believe the tranny is original, though the motor is now a 360 (not the original 352). I have recently pulled the instrument panel for various fixes, the speedo being one of them. The speedo was not working when I took it apart, and since I had the inst. panel pulled, I also pulled the cable completely out of the truck. I found the speedometer would respond to spinning the cable, so I assumed the plastic gear on the end of the cable was bad, so I replaced it (needed new ratio anyway due to rear-end swap by PO - now 2.75). I put it all back together and noticed when I put the cable assy in the tranny first, that I could spin the cable, which didn't seem right. I could feel the cable sliding into the gear, so I'm sure the cable was engaged with the gear, but I could still spin the cable.

Anyway - I finished putting it all back together and wasn't too surprised to find the speedo still doesn't work. I'm afraid the driving gear is gone/bad, but I don't know anything about that gear. Is it something that can be replaced? Easily? Without dropping the trans? What is the gear called, and where would I find one?

Thanks for any help. This is my first post, but I've been reading lots of great information that I'll be using on mine and my son's project. It's been in the family since '66...

 

I have the exact same problem. I discussed with a transmission shop -- went to school with the owner. The drive grear on the out shaft of the tranny is sort of compressed in a yoke as he described it -- no key or cogs on the shaft. If the yoke gets loose, the speedo drive gear spins on the main shaft.

Sometimes, it can be just tightened -- sometimes the gear is shot.

You can get at it without dropping the whole tranny, but the drive shaft needs to be removed, and the rear housing behind the tranny removed.

Me -- I intend to let a pro do it, mostly cause a lift makes the job a hell of a lot easier.


How do you like the 2.75 rear? I have a 3.5 rear with a 240 I6 and I wish I had a little better top end. I have a 4 speed with a granny (double low) so a 2.75 or 3.00 would not be a problem for me. I'm thinking of going to 3.00, but some folks say I'm crazy.

 

I think the 2.75 is too low - especially w/o the granny. Sure, it's great on the highway turning about 2200 rpm around 65 (I'd know for sure if my speedo worked), but there's no way I'd try to pull anything with it, and uphill starts require a lot of clutch slip. I just got the truck about a month ago and I've already got a 3.5x picked out for it.

Thanks for the info on the driving gear. It sounds like something I might have a look at when I make the rear swap (too bad - I hoped it would be something simple).

 

Well, guys, add me to your list. I replace the cable, speedo, and the little red gear, but no speedo. My speedo works great with a drill on the trans end (in reverse rotation), so I know the problem is "in there". I've gotten used to it, but my trans is kinda leaky, so I believe I'll pull it one day and put all new gaskets and seals in it, and fix that gear at the same time. I haven't spotted a new one for sale anywhere, so I hope its just loose. I may pick up another 3 speed just for that part.

 

As to the availability of the speedo drive gear -- I have a T-98 tranny (Warner) which was common in many vehicles, not just Fords. My tranny fellow says the parts, including the drive gear are easy to get.

Some things are handy at times -- a 240 I6, T98 tranny, 9 inch rear means the "guts" of my pickup are actually a lot more modern and available than the 1965 body style might indicate.

Hope we all can get our speedos working -- I'm waiting for the 3.25 chunk and then will proceed later this fall.