For 1990-2009 cars

Cause | Correction
--- | ---
Restricted or damaged ventilation tube assembly | Replace the ventilation tube as required.
Leaking fill or drain plug | Install sealant, GM P/N 12346004 (CANADIAN P/N 10953480) or equivalent onto threads of plugs and tighten
Leaking input flange seal |

1. Inspect the input flange surface of the excessive wear or damage.
2. Inspect the front bearing for wear or damage.

A worn bearing may allow excessive movement of the clutch pack input shaft.

3. Replace the components as required.

Leaks at the housing sealing surfaces | Disassemble the axle and reseal the sealing surfaces as required - clutch drum cover only.
Worn or damages axle shaft oil seals | Replace the axle shaft oil seals as required.