Ford C6 Transmission ID & Parts Guide
Ford C6 three-speed automatic transmission
The C6 is Ford's heavy-duty three-speed automatic. It went behind big V8s and diesels in full-size cars, F-Series trucks, Broncos and Econoline vans. Most C6 parts carry over for its whole run, but a few change by year: the modulator, filter, intermediate servo, rear sprag and valve body gasket. This page shows how to spot a C6 and which parts to check before you order.
C6 at a Glance
| Spec | C6 |
|---|---|
| Years | 1966–1996 |
| Typical vehicles | F-Series trucks, Bronco (1978–1991), Econoline vans, full-size Ford, Mercury and Lincoln cars, Thunderbird, Torino, and big-block Mustang and Cougar |
| Gears | 3 forward, 1 reverse; no overdrive and no lockup |
| Gear ratios | 2.46 / 1.46 / 1.00 |
| Shift control | Hydraulic, with a vacuum modulator |
| Bands and clutches | One band (intermediate). Low/reverse is a clutch pack, not a band. |
How to Identify a C6
- One-piece case. The bellhousing is cast as part of the case and cannot be unbolted. (The smaller C4 has a bolt-on bellhousing.)
- 17-bolt oil pan. A C4 pan has 11 bolts.
- Bellhousing pattern. C6 cases were cast for the small-block, FE big-block, 385-series pattern (429/460, plus the 351M/400, which share that bolt pattern), Lincoln 462 and diesel engines. A C6 only bolts to the engine family its bellhousing was cast for.
- Tailshaft length. About 7" on trucks, 14" on passenger cars and 17.4" on Lincolns.
- No lockup and no wiring. The C6 is fully hydraulic, with a vacuum modulator on the case.
C6 or E4OD? The E4OD that replaced the C6 in trucks (starting in 1989) shares many C6 parts (forward clutch, rear sprag, pump bushing), but it is a four-speed electronic unit with an overdrive. See our E4OD tech pages if your unit has a wiring connector on the case.
Parts That Change by Year
| Part | Early | Late |
|---|---|---|
| Vacuum modulator | White stripe, 1964–1972 (26160) | Black stripe, 1973-up (36160B), green stripe (36160G), or push-in purple stripe, 1975-up (36160P) |
| Filter, 2WD | 1966–1974 (A36010A) | 1975-up (A36010B) |
| Filter, 4WD | 1973-up (3044) | |
| Valve body gasket | 1966 (3029A) | 1967–1996 (3029B) |
| Rear (low/reverse) sprag | A36654D fits every C6. (The later 17-roller sprag is for E4OD/4R100 only; no C6 uses it.) | |
| Bearing kit | — | 1976-up Torrington bearing kit (36201A) |
Which Intermediate Servo Piston?
C6 intermediate servo pistons come in several diameters, matched to the servo cover. Measure the old piston across its sealing surface and order the same size.
For a firmer band apply, rebuilders use the largest "R" ratio servo: the Sonnax R ratio servo piston kit (mid-1968-later) or Superior's billet Super Servo (K016), with replacement seals sold separately.
Common C6 Rebuild Parts
| Part | Notes |
|---|---|
| C6 overhaul kit (3016A) | Gaskets and seals, late 1967–1996. Our top-selling C6 item. |
| C6 master rebuild kit, build your own (RKC6-CUSTOM) | Add frictions, steels, bands, filter and bushings to the overhaul kit. |
| Pump repair kit with gear set (PKC6G-Kit) | Or the seal-only pump kit (PKC6-KIT), the pump gear set (A36530) and a rebuilt pump. |
| Master bushing kit (3031) | 10 pieces. Thrust washers: 3037 (no selectives). |
| Intermediate band (3022A) | Also the wide Red Eagle performance band and the Sonnax extra-wide band. |
| Steel plate module (3183A) | Or the Kolene performance module (3182K) and HD Kolene direct steels. |
| Pan gasket, Farpak (3024AF) | Also in cork (3024A). |
| Upgraded forward clutch hub snap ring (Superior K0111) | Fits C6, E4OD and 4R100. |
| Band adjustment nut (A36922) | Lock nut for the intermediate band adjusting screw. |
Shift Kits and Upgrades
- TransGo SK6 shift kit (fits 1967-on C6, gas and diesel) and TransGo shift reprogramming kit
- Superior valve body shift kit with HD boost valve
- Superior high-performance upgrade kit
- Heavy-duty input shaft
Shop Ford C6 parts · All Ford transmission tech info
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