Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Overhaul - Borg-WARNER T56 6-Speed: Description
The Borg-Warner T56 transmission is a fully synchronized 6-speed gear box. GM also identifies it as 85-mm 6-speed. Transmission is used in vehicles equipped with a 5.7L engine. The transmission has an aluminum case with internal shift rail mechanism. Manufacturer recommends Dexron II automatic transmission fluid to protect synchronizer friction material.
Transmission is equipped with a solenoid which operates a reverse lock-out assembly. Solenoid prevents operator from shifting transmission into Reverse when vehicle is moving forward.
To enhance fuel economy, transmission also is equipped with a gear select solenoid, which inhibits 2nd and 3rd gears when shifting from 1st gear. Solenoid is activated when engine coolant temperature is greater than 162°F (77°C), vehicle speed is between 15-21 MPH and throttle is opened 35 percent or less.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.