Automatic Transmissions

Is your automatic transmission slipping since the engine was tuned, or do you want firmer shifts? We bring together automatic transmissions, complete transmission packages and performance valve bodies for diesel vehicles and drag racing projects where the stock transmission can no longer keep up with the engine's torque.

Transmission packages, valve bodies and complete transmissions

The category covers three types of parts. Transmission packages from ATS Diesel are available in stages such as Stage 1, 2 and 3 for transmissions like the 48RE, 68RFE and E4OD. A performance valve body – the hydraulic control unit that distributes oil pressure to the transmission's clutches – can give firmer shifts without replacing the entire transmission, and ATS Diesel offers valve bodies for the LCT1000, 68RFE and 6R140, among others. For drag racing there are TH400 transmissions from FTI Performance, e.g. Level 4.5 with transbrake and reverse shift pattern. You will also find parts from BD Diesel, and fully assembled transmissions are listed under complete automatic transmissions.

How to choose an automatic transmission

• Transmission code and model year: Part numbers are tied to specific transmissions, model years and 2WD or 4WD, e.g. the 68RFE valve body from 2012 for the grey connector on the solenoid pack. Check the transmission code on your vehicle.
• Power target and use: Choose the stage based on the engine's actual torque and whether the vehicle is used for daily driving, towing or track. A higher stage is not automatically the right choice.
• Valve body or full package: If the transmission's mechanical parts are in good condition, a valve body may be enough. If they are worn, a package or a rebuild kit may be relevant.
• Bellhousing for TH400: Choose a variant, e.g. GM Ultrabell or SFI bellhousing, based on the engine and the rules of your class.
• Related parts: The result also depends on the torque converter and the transmission control.

Frequently asked questions

What is the difference between a valve body and a full transmission package?

A valve body changes how oil pressure controls the shifts and can give firmer shifts. A package typically includes several parts of the transmission. What is necessary depends on the condition of the transmission and the torque it has to handle.

Does an upgraded automatic transmission or valve body require new transmission control?

It depends on the product and the vehicle. Some solutions can use the existing control unit, while others require adjustment. Check the description for the specific part number, and consider the torque converter and control at the same time.

How do I maintain an upgraded automatic transmission?

Follow the manufacturer's instructions for oil type and change interval. Higher loads can increase oil temperature, especially when towing or on track, and overheated oil can wear clutches and seals faster. It is therefore a good idea to keep an eye on the temperature.