09G TF-60SN CVT automatic transmission K1 drum clutch assembly

Key Specifications & Analysis

1. Function: 1st/3rd/5th gear engagement in VW/Audi transverse 6-speed applications.

2. Design:

   • 3-piston clutch pack (5 friction plates, 6 steel plates)

   • Drum material: Hardened aluminum (Si-Cu alloy) with anti-wear coating

3. Critical Tolerances:

   • Plate clearance: 1.2–1.6mm (new), >2.0mm requires replacement

   • Piston stroke: 2.8–3.2mm

4. Failure Modes:

   • Seal leaks (causing delayed engagement)

   • Drum spline wear (>0.2mm play leads to shudder)

   • Overheating (if ATF degraded, causing plate glazing)

Note: Uses VW G 055 025 A2 fluid; common failure in high-mileage units.