TH400 4WD Performance Transmission – Short Output
F400T-FCB
The TH400 4WD Performance Transmission is a heavy-duty automatic transmission built for rock crawlers, rock bouncers, trail rigs, competition vehicles, and custom 4x4 applications that need the strength and simplicity of the GM Turbo 400 platform. Each transmission starts with a factory Chevrolet TH400 case that is thoroughly inspected and cleaned before assembly, then rebuilt with performance internal components for off-road use.
This transmission uses a manual valve body and can be configured with either a forward-pattern or reverse-pattern valve body, with the additional option of compression braking or no compression braking. Internal upgrades include a 34-element intermediate sprag, high-friction clutch materials, a Kevlar grooved rear band, and upgraded .060" forward steels. A torque converter is not included, allowing the converter to be chosen separately based on engine combination, vehicle weight, tire size, gearing, and intended use.
Key Build Components:
- Factory Chevrolet TH400 Case – Inspected and Cleaned
- TH400 4WD Short-Output Configuration
- Manual Valve Body
- Choice of Forward or Reverse Shift Pattern
- Choice of Compression Braking or No Compression Braking
- 34-Element Intermediate Sprag
- High-Friction Clutch Package
- Kevlar Grooved Rear Band
- .060" Forward Steels
Torque Converter: Not included.
Specifications
| Specification | Details |
|---|---|
| Transmission | GM TH400 / Turbo 400 |
| Transmission Type | 3-Speed Automatic |
| Case | Factory Chevrolet TH400 Case, Inspected and Cleaned |
| Application | 4WD / Off-Road |
| Output Configuration | Short 4WD Output |
| Valve Body Type | Manual Valve Body |
| Shift Pattern Options | Forward Pattern or Reverse Pattern |
| Compression Braking Options | With Compression Braking or Without Compression Braking |
| Intermediate Sprag | 34-Element |
| Clutch Package | High-Friction Performance Clutches |
| Rear Band | Kevlar Grooved |
| Forward Steels | .060" Steel |
| Vacuum Modulator | Not Used with Manual Valve Body |
| Torque Converter | Not Included |
Fitment
| Application | Typical Use |
|---|---|
| Rock Crawlers | Low-speed technical terrain and high-load drivetrain use |
| Rock Bouncers | High-horsepower, high-impact off-road applications |
| Trail Rigs | Heavy-duty custom 4WD drivetrains |
| Competition Vehicles | Manual-shift off-road and race applications |
| Custom Tube Chassis | Purpose-built drivetrain installations |
| Custom Jeep / 4x4 Builds | TH400-based drivetrain conversions |
Fitment Notes:
- Designed for custom 4WD applications using a GM TH400 transmission.
- Short-output configuration is intended for transfer-case applications.
- Choose the valve body shift pattern that matches your preferred shifter operation: forward pattern or reverse pattern.
- Choose compression braking based on how you want the transmission to behave during deceleration and downhill operation.
- This transmission does not use a vacuum-operated modulator because it is equipped with a manual valve body.
- Torque converter is not included and must be selected separately for the engine, vehicle weight, tire size, axle gearing, and intended use.
- Transfer case, transfer-case adapter, shifter, cooler, lines, flexplate, driveshafts, and installation hardware are not included unless specifically stated.
- Verify engine bellhousing compatibility and complete drivetrain configuration before ordering.
FAQ
What is a manual valve body TH400?
A manual valve body requires the driver to select each gear manually with the shifter rather than relying on the transmission to make automatic gear changes. This gives the driver direct control over shift timing, which is useful in rock crawling, racing, and other performance applications.
What is the difference between a forward-pattern and reverse-pattern TH400 valve body?
The difference is the order of the forward gears on the shifter. A forward-pattern valve body follows the more traditional shift direction, while a reverse-pattern valve body changes the gear order so upshifts are made in the opposite direction. The correct choice depends on driver preference and shifter configuration.
What does compression braking mean on a manual valve body?
Compression braking allows the transmission to provide engine braking when the driver selects a lower gear and releases the throttle. This can be useful for technical descents and controlling vehicle speed without relying entirely on the brakes. A non-compression-braking setup allows the vehicle to freewheel more when off throttle in certain selected gears.
Does this TH400 use a vacuum modulator?
No. This transmission uses a manual valve body, so the vacuum-operated modulator used on conventional automatic-shift TH400 applications is not part of this setup.
Does this TH400 include a torque converter?
No. The torque converter is sold separately so the stall speed and converter design can be matched to the engine, camshaft, vehicle weight, tire size, axle gearing, and intended use.
