Trutech Logo


Sonnax Super Hold Servo Kit Powerglide 28821-09K

Product Description For Sonnax Parts
Product Part No: -- 28821-09K
Transmissions: -- Powerglide
Package and Weight
Package Quantity: -- 1 ea
Shipping Weight: -- 2.50 lbs
Sonnax:High Performance Part
Base Price:
Product Description

Part Informations

  • Dual piston design for 30% more apply area:
  • Spring counteracts pin bias effect up to 275 psi:
  • Improved sealing throughout:
  • Low-profile design ensure adequate clearance:
  • 6061 Anodized billet aluminum cover:

Part Contants -

  1. Servo Assembly:
  2. Cover Gasket:
  3. Case-to-Cover O-Ring:
  4. Return Spring:
  5. Servo Pin Seals (2) PTFE, 1 extra:
  6. Primary Piston Seals (2) PTFE:
Note: A common question is, "I have an extreme application, when would I choose the Smart-Tech servo over the Sonnax super hold?":
Both are track-proven in today’s high-power vehicles. With its ratio-style release and supported pin design, the Smart-Tech is the best all-around upgrade that eliminates EVERY problem associated with the OE servo. Racers looking to reduce line pressure for greater efficiency will most benefit from the super hold servo’s 30% more apply area.
Trutech/Procare Transmissions
406 East Park Ave
Enterprise, Alabama 36330
Email Us @:
Customer Service
1-800-762-9846 Inside USA
1-334-577-4400 Outside USA