6AT GM 6T30
The 6AT GM 6T30 gearbox is fitted to 5 generation(s): Chevrolet Cobalt, Chevrolet Nexia, Daewoo Gentra, Chevrolet Aveo.
Common problems and what to check
Gearbox: GM 6T30/6T40/6T45, etc.
- broken wave spring in the 3-5-R clutch pack (6T40/6T45)
- jerks when the valve body wears
What to check when buying: loss of 3rd/5th gear and reverse; shift shocks.
Tip: Oil every 60k km; avoid hard launches when cold.