Based on the ultra-durable, one-piece Sonnax heavy duty input shaft 22121B-01 for Chrysler 47RE, 47RH, and 48RE units, the Smart-Tech input shaft and piston kit 22121B-02K has a hub with longer direct (front) clutch splines. Combining longer splines with a thinner billet aluminum direct piston allows for one extra (OE-thickness) direct friction plate, while keeping OE-thickness steels, backing plate, OE waved retaining ring and OE clutch clearances.
Some common aftermarket modifications designed to include extra clutches require reduced steel thickness and decrease the heat absorption capacity of the clutch pack, others reduce clearance and eliminate the waved retaining ring, which contributes to excessive 2-3 shift overlap. The Sonnax kit avoids these problems by increasing the number of frictions from five to six, adding to the steel mass of the clutch pack, and maintaining the OE thickness backing plate and clearances for the optimum combination of increased capacity and durability.

Kit increases direct clutch capacity by 20%
Custom forged from ultra-high strength 300M billet steel
One-piece design eliminates weak connection between input shaft and forward clutch hub
No change to backing plate thickness or retaining ring

More From This Category

Sonnax Extreme Strength Ringless Input Shaft, GM, Powerglide, Each

Sonnax Extreme Strength Ringless Input Shaft, GM, Powerglide, Each

$1,284.78

Motive Gear Axle Shaft, 1541 Manganese, 6x5.5 in. Bolt Pattern, 30.75 in. Length, 30SPL, For CHEVROLET BLAZER 1969, Each

Motive Gear Axle Shaft, 1541 Manganese, 6x5.5 in. Bolt Pattern, 30.75 in. Length, 30SPL, For CHEVROLET BLAZER 1969, Each

$244.42

Motive Gear Axle Shaft, 1541 Manganese, 5x5 in. Bolt Pattern, 33.316 in. Length, 28SPL, For CHEVROLET G10 1975–1988, Each

Motive Gear Axle Shaft, 1541 Manganese, 5x5 in. Bolt Pattern, 33.316 in. Length, 28SPL, For CHEVROLET G10 1975–1988, Each

$202.02

Sonnax Tcc Pwm Solenoid, GM, 4T65E ('97 - Later), Each

Sonnax Tcc Pwm Solenoid, GM, 4T65E ('97 - Later), Each

$53.10

TCI Transmission Input Shaft, 4340 Steel, GM, 4L80E, Each

TCI Transmission Input Shaft, 4340 Steel, GM, 4L80E, Each

$872.67