C4 Specs + Identification




 

History

The C4 is a transmission that was produced by the Ford Motor Company starting in 1964.  When first released it was known as the “3 Speed Cruise-O-Matic”  Like GM and the switch from Powerglide to TH350, Ford replaced the iron case of the “Ford-O-Matic” that it replaced.  It was engineered to work with rear-wheel drive vehicles.

The transmission stayed relatively the same for its first 5 years of production.  In 1970 the engineers at Ford gave it its first design changes.  These changes gave the C4 upgraded internals capable of handling more power and increased its durability.

The C4 was used in light duty vehicles such as the Mustang, Torino, and Falcon.  It also was used in the F150 until production ceased.  It still is a pretty popular transmission with bracket racers due to its 110 pound weight.  Unlike most early transmissions, where the case is fused with the bellhousing, the C4’s is removable.  this allows it to be custom fit to vehicles it was never intended on running in.  Regardless of model year, the C4 can have a dipstick that goes directly into the pan or the case.  Usually car versions had the dipstick in the case.



In 1982 the C4 was upgraded to the C5.  Like in 1970, it was upgraded to handle more power and increase reliability.  It also got a locking converter to help Ford meet ever tightening fuel mileage requirements.  This transmission lasted for only 4 years.

 

C4 Specs

Manufacturer:  Ford Motor Company
Production:  1964-1982
Type:  3 Speed Automatic
Gear Ratios:
  • First- 2.46:1
  • Second- 1.46:1
  • Third- 1:1
  • Reverse- 2.18:1
Input Shaft:
  • 1969 and older:  24 spline
  • 1970:  26 spline
  • 1971 and up
Torque Converter Lock:  No
Overdrive:  NO
Case Length:Different applications had different lengths due to different tail shafts/transfer cases.
Outer Case Material:  Aluminum
Controlled by Computer: No
Weight:  Roughly 110 lb. without the converter or fluid.

 

C4 Transmission Identification

There is not much to figuring out whether or not you are looking at a C4 transmission.  The real trick is identifying which C4 you are looking at.  Lets get straight to it.  The C4 was never put behind any engine that had a displacement over 400 cubic inches. So, unless you are looking at any big block other than the 400, you can rule out the C4.

The speedometer cable is attached to the driver’s side tail shaft, if you are looking under the car, that is a good place to start.  The tail shaft or transfer case bolt to the C4 with six bolts.

The most effective way to identify which three speed Ford automatic that you are looking at is to count the number of bolts used to secure the transmission pan.  They each use a different number, so there really is no confusion.   There are 11 bolts on the C4.  Pan shape is more uniform than GM automatic transmissions, but they each do have a different shape.

C4 Identification

As stated earlier, the 1960’s version of the transmission had a vent tube on the passenger side.  It was eliminated for the 1970 model year and never returned.  So if you see that tube, you can fairly assume that you have identified an early model.

In the 1970 and later version it has something called a “jiggle pin”.  It stays on top of the housing by the tail shaft and vents the case.  It is just a basic valve that pops open when the case gets enough pressure.  If you happen to be looking at a transmission without a tail shaft/transfer case you can identify it as a C4 4×4 transmission by the tube coming from where the jiggle pin normally would be.  Either way, if you see the jiggle pin you know you have found a 1970+ model.

1973+ models have a push in modulator, whereas all the earlier ones screwed in.  The modulator is located on the back of the case above the pan.

You can tell whether you have the weaker car line version of the C4 by looking at the bolts that fasten the bellhousing to the case.  If the bolts hold the pump and the housing than it probably came from a car.  The car versions also used a shallower pan until the late 70’s

There are so many different versions of the C4.  There are over ten different bell housings depending on which one you are looking at you need to make sure that it is compatible with the engine that you would like to drop in.  They are removable though, so don’t sweat it too much, but it’ll give you a great idea where the transmission came from.  Here is a pretty good guide to figuring out which bellhousing is currently on your C4.

Conclusion

The C4 transmission is still a great transmission to use for your hot rod, bracket racer.  Finding them at swap meets isn’t very hard.  Keep your eyes peeled and you’ll find one on craigslist for under $200.  As long as you feel like you don’t need overdrive you can’t go wrong with it.

 


Posted in Ford

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