6HP26, 6HP26X, 6HP28, 6HP28X

The ZF 6HP26, 6HP26X, 6HP28 and 6HP28X are 6-speed electronically controlled automatic transmissions developed for high-torque longitudinal-engine applications. The 6HP28 is an updated development of the 6HP26, while the X variants are configured for applicable all-wheel-drive installations. The family uses a torque converter with controlled lock-up clutch and integrated electro-hydraulic mechatronic control.

Specification: 6-speed automatic • ZF 6HP26 / 6HP26X / 6HP28 / 6HP28X • Longitudinal installation • RWD and AWD applications • Torque converter with controlled lock-up clutch • Planetary gearset arrangement • Integrated electro-hydraulic mechatronic control • 4.17:1 first gear • 0.69:1 sixth gear • 3.40:1 reverse • Approximately 6.04:1 ratio spread • Up to approximately 600 Nm depending on version • ZF LifeguardFluid 6 • Multiple application-specific variants.

The family is fitted across selected BMW, Jaguar, Land Rover, Ford, Lincoln, Aston Martin and other applications, with the X versions used in applicable AWD configurations. Specifications and components vary considerably, so the VIN, complete transmission number, OEM gearbox code and individual component identification should always be confirmed before ordering replacement parts.

Common Faults

Common 6HP26 / 6HP28 family problems include valve-body and mechatronic faults, pressure-control or solenoid wear, torque-converter lock-up wear, hydraulic leakage and internal clutch wear. Symptoms can include harsh or delayed shifts, shift flare, slipping, converter judder, incorrect gears, transmission warnings and failsafe operation.

Mechatronic sealing and hydraulic pressure loss are important diagnostic areas. Valve-body wear or pressure loss can cause significant shift problems without necessarily indicating major internal failure, so diagnosis should include fault codes, adaptations, hydraulic operation, converter function and fluid condition.

Common Fault Codes