Speedo Gear

Clutch, transmission, rear axle

Moderators: FORDification, 70_F100

Post Reply
Old Bird
New Member
New Member
Posts: 96
Joined: Fri Apr 17, 2009 4:04 pm
Location: Northern New Mexico

Speedo Gear

Post by Old Bird »

The 68 F250 that I picked up yesterday doesn't have a speedo cable. I'm planning on getting a shop manual and a new speedo cable, and just to be sure, a new speedo gear. The problem is selected the right gear. I did a search and found lots of discussion on the topic, but no direct answer, so I'm hoping someone here has a specific answer for this. It seems like in order to find the right number of driven gears for the speedo cable, you need to know the number of teeth on the drive gear. I'm hoping someone with the same setup as me has either the number of drive teeth or driven teeth so I can order the right gear the first time.

My truck, which I believe is stock, has the 390, automatic (c4?) and according to the code (37) a Dana 60 with 3.54 rear gear. Tires are stock size.

Does anyone know the number of drive teeth on this setup or the number of driven teeth that I need for it?

Thanks!
Timothy

It's for my twin boys, sure they're only 3 right now, but it's all for them! Well, and my twin girls. They're not even 1 yet, but when they are I'll have a pit crew!

Toys:
62 Thunderbird Convertible
68 F250 Ranger 2wd - 390 C6
fordman
100% FORDified!
100% FORDified!
Posts: 22329
Joined: Sun Aug 28, 2005 8:17 pm
Location: Kansas, Ottawa
Contact:

Re: Speedo Gear

Post by fordman »

you probably dont need the gear. its probably still inside of the trasnmission. remove the gear holder real quick and count the teeth on it. then you can get a new gear.
Old Bird
New Member
New Member
Posts: 96
Joined: Fri Apr 17, 2009 4:04 pm
Location: Northern New Mexico

Re: Speedo Gear

Post by Old Bird »

I'll check that out when I get a chance, which unfortunately won't be for at least a week. I was hoping someone with the same setup had an answer though, so I could order the gear and have it on hand if I need it. I don't get too many opportunities to work on the truck, so waiting a week to check then a few weeks before I can put the new one in is a PITA.
Timothy

It's for my twin boys, sure they're only 3 right now, but it's all for them! Well, and my twin girls. They're not even 1 yet, but when they are I'll have a pit crew!

Toys:
62 Thunderbird Convertible
68 F250 Ranger 2wd - 390 C6
User avatar
FORDification
Site & Forum Admin
Site & Forum Admin
Posts: 8050
Joined: Sun Jul 11, 2004 12:52 am
Location: Kansas, Wellsville
Contact:

Re: Speedo Gear

Post by FORDification »

The C4 was never available behind an FE, so you will have either a Cruise-O-Matic or a C6, depending on whether or not the transmission is original. The gears differ between the two transmissions, so before you order anything, you're going to have to find out for sure what you've got and go from there.

I'd venture a guess the gear is still on the transmission, since if it was removed you'd have had a large hole in the side of the case, and the rapid loss of transmission fluid would've been pretty obvious. ;)

Also, C6 transmissions don't all have the same number of drive teeth machined into the output shaft. They can have 6, 7 8 or 9 teeth, so if you do need to replace a bad (or missing) gear, you'll need to look down into that hole and do a count.
____| \__
-O-----O- Keith
'67 F-100 2WD SWB ~ '69 F-100 4WD SWB w/7" chop ~ 1975 F-250 Ranger XLT Supercab Camper Special
ImageImageImage
My '67 restoration video
-> Posting and you! <-a MUST watch for all!!
Old Bird
New Member
New Member
Posts: 96
Joined: Fri Apr 17, 2009 4:04 pm
Location: Northern New Mexico

Re: Speedo Gear

Post by Old Bird »

FORDification wrote:The C4 was never available behind an FE, so you will have either a Cruise-O-Matic or a C6, depending on whether or not the transmission is original. The gears differ between the two transmissions, so before you order anything, you're going to have to find out for sure what you've got and go from there.

I'd venture a guess the gear is still on the transmission, since if it was removed you'd have had a large hole in the side of the case, and the rapid loss of transmission fluid would've been pretty obvious. ;)
LOL - that probably would have presented itself on the 80 mile trip back home, at the 75 mph speed limit the whole way.

Thanks, I'll check on it. Any obvious spotting differences between the c6 and the cruise-o-matic? With the exception of the MSD ignition and dizzy and the holley carb, this truck seems like it's pretty original.
Timothy

It's for my twin boys, sure they're only 3 right now, but it's all for them! Well, and my twin girls. They're not even 1 yet, but when they are I'll have a pit crew!

Toys:
62 Thunderbird Convertible
68 F250 Ranger 2wd - 390 C6
User avatar
FORDification
Site & Forum Admin
Site & Forum Admin
Posts: 8050
Joined: Sun Jul 11, 2004 12:52 am
Location: Kansas, Wellsville
Contact:

Re: Speedo Gear

Post by FORDification »

____| \__
-O-----O- Keith
'67 F-100 2WD SWB ~ '69 F-100 4WD SWB w/7" chop ~ 1975 F-250 Ranger XLT Supercab Camper Special
ImageImageImage
My '67 restoration video
-> Posting and you! <-a MUST watch for all!!
mmerlinn
New Member
New Member
Posts: 190
Joined: Thu Jan 22, 2009 11:45 am
Contact:

Re: Speedo Gear

Post by mmerlinn »

FORDification wrote:The C4 was never available behind an FE, so you will have either a Cruise-O-Matic or a C6, depending on whether or not the transmission is original. The gears differ between the two transmissions, so before you order anything, you're going to have to find out for sure what you've got and go from there.

I'd venture a guess the gear is still on the transmission, since if it was removed you'd have had a large hole in the side of the case, and the rapid loss of transmission fluid would've been pretty obvious. ;)

Also, C6 transmissions don't all have the same number of drive teeth machined into the output shaft. They can have 6, 7 8 or 9 teeth, so if you do need to replace a bad (or missing) gear, you'll need to look down into that hole and do a count.
C4s did come behind an FE motor in some vehicle probably only in 1964. I have owned one FE C4 bell housing in the past and I know where there is one in California today.
mmerlinn (http://mmerlinn.com/catalog/makeridx.htm)

"People who are careless and sloppy writers are usually also careless and sloppy at thinking. Answering questions for careless and sloppy thinkers is not rewarding." - Eric Steven Raymond
Old Bird
New Member
New Member
Posts: 96
Joined: Fri Apr 17, 2009 4:04 pm
Location: Northern New Mexico

Re: Speedo Gear

Post by Old Bird »

Based on the description there, it's a c6. It's a one piece tranny, no separate bell housing. That's what the seller listed in his add as well, it was a mind slip when I typed it above. I believe this truck is mostly stock.
Timothy

It's for my twin boys, sure they're only 3 right now, but it's all for them! Well, and my twin girls. They're not even 1 yet, but when they are I'll have a pit crew!

Toys:
62 Thunderbird Convertible
68 F250 Ranger 2wd - 390 C6
Post Reply