Smart-Tech® 10-Clutch Drum Kit
Part No. 28756-25K

View Instructions Find a Distributor

Sonnax Smart-Tech 10-clutch drum kit 28756-25K for GM Powerglides features a 35% larger piston that maximizes both engaging and holding capacity of the 10-clutch system. Smart-Tech components give you the option to reduce line pressure for greater efficiency, or drop to seven frictions for less parasitic drag and improved heat dissipation while retaining 10-clutch capacity.

Sonnax 10-clutch drum kits are optimized for Powerglide performance applications. Using the patented Sonnax 10-clutch drum system, the drum and piston accept 10 .060" frictions and 10 .060" thick steels, increasing lockup surface to allow significantly more torque than modified OE drums. The Sonnax drum has material removed for the kit's bearing, allowing overall stack up to be .060" taller than an OE drum alone.

  • 35% More apply area
  • Use with your choice of frictions and steels
  • Patented drum, hub and piston system improves clutch capacity for maximum durability
  • High-strength drum with reduced rotating mass improves on-track acceleration
  • 6061 Forged piston will not crack like cast pistons
  • Forged chromoly clutch hub guarantees your power makes it to the wheels
  • Thrust bearing used between pump and drum
  • Shim Narrow
  • 10-Clutch Hub
  • Thrust Bearing
  • High Clutch Return Springs (24)
  • Clutch Drum Spring Retainer
  • Smart-Tech 10-Clutch Drum
  • Smart-Tech 10-Clutch Piston
  • Bushing PTFE Coated, Installed
  • Retaining Ring Small
  • Inner & Outer Lip Seals Not Shown
  • Shim Wide

  • Powerglide Smart-Tech® 10-Clutch Drum Kit 28756-25K
  • Powerglide Smart-Tech® 10-Clutch Drum Kit 28756-25K details


From the Bench: Building a World‑Class Powerglide Racing Transmission

I've used several of the Powerglide 10-clutch drum kits in drag racing performance builds. The quality and reasonably priced product makes the choice to use over a stock or reconditioned drum a no-brainer.

G. Carson
Speedy's Automotive