C4 Transmission Rebuild and Swap



While searching the local Seattle craigslist "Free" section, I came across an ad for a 1966 case fill C4 transmission from a Mustang. I had been wanting to replace my Ford-o-Matic so I figured this was the perfect opportunity. I picked it up on a rainy day and placed it in the garage to dry out. Nearly a year later and a 1,600 mile round trip to the FCA National Convention in the near future...I decided it was time to get it rebuilt and installed.

On a scale of 1 (easiest) to 10 (most difficult) I would say this project was a 6. If you're mechanically inclined, patient, and don't mind getting dirty, you can save yourself a good chunk of money by doing it yourself. I won't get into the specifics of most of the rebuild as there are other good sources available for that. I had help from a friend who had just recently rebuilt a later model C4 and he also loaned me the Haynes Techbook #10355 "Ford Automatic Transmission Overhaul" book and a video by the company Technical Video #1204 "Ford C-4." These were both excellent sources of information with easy to follow, step-by-step instructions.

I rebuilt the transmission over the course of a few weekends and decided to take a Friday and Monday off work to do the swap. My rebuild was strictly stock as that is more than sturdy enough to hold up behind my 200 i6. Although I still had a few details to work on, I got it done and was driving to work Tuesday morning. Below are some photos I took during the process along with comments and a few links I found helpful. Also, scroll down for a list of the expenses involved. Take the Full Tour or click on the links below to view individual photos.


Oiler Modification

#9 Thrust Washer

Assembled Case

Valve Body

Shift Kit

Green Dot




Mount & Adaptor

Oil Cooler Bracket

Oil Cooler

Up on Jacks

Old Ford-o-Matic

Tranny Jack

Rear Mount



Inspection Plate

Detent Plate

Compare Detents

Indicator Lens

Comet Collar

Shift Linkage

Column Shift


Carb Linkage

Gas Pedal Front

Gas Pedal Back

Driven Gear

Helpful Links

C4 Rebuild and Swap Expenses (includes taxes and shipping)

$00 - `66 C4 Transmission Core
$90 - Throttle linkage, kickdown assembly from `65 w/C4
$20 - Powerwash case & bellhousing, used pan
$41 - Master Rebuild Kit
$34 - Pump Gear, Thrust Washer, Modulator, Flexplate
$19 - Transgo Shift Kit
$38 - Tru-Cool Auxiliary Oil Cooler
$85 - C4 Mount Adaptor
$17 - C4 Rubber Mount
$21 - Cruise-o-Matic Indicator Lens
$22 - Column Shift Detent Plate
$91 - Torque Converter
$44 - Valve Body
$148 - Shorten Driveshaft, Weld Yoke, Balance, U-joint Kit
$80 - Misc. parts, hardware, tools, paint, etc.

$750 Grand Total (does not include beer and pizza)

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