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 Pinion Batwing Washer, GM 4L80E '99-Up

Sonnax Pinion Batwing Washer, GM 4L80E '99-Up

$31.77

Motive Gear Axle Shaft, 1541 Manganese, 4x4.25 in. Bolt Pattern, 29.1875 in. Length, 28SPL, For CHRYSLER COMET 1978–1981, Each

Motive Gear Axle Shaft, 1541 Manganese, 4x4.25 in. Bolt Pattern, 29.1875 in. Length, 28SPL, For CHRYSLER COMET 1978–1981, Each

$216.19

Sonnax Direct/Input/High & Low Reverse Clutch Solenoid, Re5R05A, Each

Sonnax Direct/Input/High & Low Reverse Clutch Solenoid, Re5R05A, Each

$176.23

TCI Input Shaft, Hardened, Vaccu Melt 300, Stock Carrier, Stock Spline, For Ford, Automatic, AOD, Non-Lockup, Each

TCI Input Shaft, Hardened, Vaccu Melt 300, Stock Carrier, Stock Spline, For Ford, Automatic, AOD, Non-Lockup, Each

$626.72

Sonnax Oversized Lockup Control & Plunger Valve Kit, JF016E, JF017E, Each

Sonnax Oversized Lockup Control & Plunger Valve Kit, JF016E, JF017E, Each

$125.08

Sonnax Valve Body Separator Plate, ZF8Hp55, Each

Sonnax Valve Body Separator Plate, ZF8Hp55, Each

$93.72