M32 6-Speed Manual Gearbox Bearing Failure
SeriousGearbox & TransmissionThe GM-FPT M32 6-speed manual gearbox fitted to Grande Punto and early Punto Evo models is prone to premature wear and pitting of the output shaft and 6th gear end-casing bearings. Excessive factory preload tolerances, poor lubrication to the upper bearings, and thermal fluid breakdown lead to spalling of the bearing tracks. As the bearings degrade, a pronounced whine develops in 1st, 2nd, and 6th gear, accompanied by noticeable gearstick twitching under acceleration and overrun. If ignored, the bearings disintegrate completely, punching through the aluminium casing and causing total transmission failure.
Whining or droning noise in 1st, 2nd, and 6th gear that increases with road speed, Visible twitching or jumping of the gear selector lever when applying or releasing the throttle, Difficulty or crunching when engaging 1st, 2nd, or reverse gear when warm, Metallic grinding noise from the transmission bellhousing during motorway driving
- During the test drive, place light fingertip pressure on the gear knob in 1st and 6th gear to observe any fore-aft movement under hard acceleration
- Drive at 50–60mph in 6th gear and gently modulate the throttle, listening for a high-pitched bearing whine
- Inspect the aluminium end-casing behind the front nearside wheel arch for transmission fluid weeping
- Check the service history for documentation of gearbox bearing overhaul or upgraded synthetic fluid changes