The GM 4L60, 4L60-E, 4L65-E and 4L70-E input drum assembly is known to crack where the input shaft is pressed into it (where the overrun clutch rides).
Sonnax offers a hardened steel sleeve that reinforces the input drum to prevent this failure. OE overrun pistons must be machined when using Sonnax input drum reinforcement kit 77733-02K.

Sleeve made from hardened chromoly steel
Can be installed in early- and late-model units*
Sleeve design will not block clutch feed oil

More From This Category

Sonnax Servo Pin Bore Reaming Fixture, Multiple, Each

Sonnax Servo Pin Bore Reaming Fixture, Multiple, Each

$436.10

Motive Gear Differential Bearing Kit, Timken, For CHEVROLET BEL AIR 1965–1970, Kit

Motive Gear Differential Bearing Kit, Timken, For CHEVROLET BEL AIR 1965–1970, Kit

$167.73

Sonnax Zip Kit®, Ford, 6R140, Each

Sonnax Zip Kit®, Ford, 6R140, Each

$265.15

Motive Gear Differential Pinion Bearing Kit, Koyo, For CHEVROLET AVALANCHE 2500 2002–2006, Kit

Motive Gear Differential Pinion Bearing Kit, Koyo, For CHEVROLET AVALANCHE 2500 2002–2006, Kit

$205.00