The U151F automatic transmission low gear clutch drum assembly 3420428011 is applicable to Toyota Hanlan Da

• • • • Function: Engages low/reverse gears by actuating multi-plate clutch packs in planetary gearset applications (common in 4WD/RWD transmissions).

        Key Components:

        • Drum Body: Hardened aluminum or steel with precision splines for clutch plate engagement

        • Integrated Piston: Hydraulically actuated with reinforced seals for high-pressure apply (60-100 psi)

        • Bleed Channels: Prevent clutch drag during release

        Failure Modes:

        • Spline Wear: Causes incomplete clutch engagement (slippage in low gear)

        • Piston Seal Leaks: Results in delayed reverse engagement

        • Drum Cracks: Thermal stress near weld points (sudden loss of drive)

        Critical Checks:

        1. Measure drum runout (<0.08mm)

        2. Verify clutch clearance (1.0-1.8mm typical)

        3. Inspect for blueing (overheating evidence)

        Pro Tip: Always replace drum seals during rebuilds – reused seals have 80% higher failure rate.

        
        

        

3420428011 Clutch Drum Assembly

automatic transmission Clutch Drum Assembly

3420428011 Clutch Drum Assembly

The U151F automatic transmission low gear clutch drum assembly 3420428011 is applicable to Toyota Hanlan Da Images