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Sonnax 28821-20K Supported Servo Master Kit Everything Needed For The Powerglide

$ 60.48

Availability: 89 in stock
  • Other Part Number: S28821-20K
  • Condition: New
  • Interchange Part Number: 28821-20K
  • Manufacturer Warranty: Yes
  • Manufacturer Part Number: 28821-20K
  • Brand: Sonnax

    Description

    Powerglide
    Supported Servo Master Kit
    Part No.
    28821-20K
    Conventional GM Powerglide servos are not well-supported and the return springs do not function properly, both leading causes of band failure. Sonnax supported servo master kit 28821-20K is an all-in-one kit that eliminates piston binding and includes a race-calibrated spring to counteract the pin bias effect.
    At high apply pressures or with a worn servo pin bore, the servo piston is side-loaded in the case, causing friction and binding of the piston. The supported pin design of this Sonnax kit eliminates friction caused by side-loading and ensures the servo piston will apply and release without binding.
    "Mystery" band failures are a common result of aftermarket servo return springs and weak OE springs prone to collapse that do not reliably release the servo. The Sonnax spring in this kit is race-calibrated to ensure consistent servo function for longer band life and a cooler transmission. The spring's higher seat pressure helps ensure full servo release, but also features a lower spring rate to prevent excessive release force in the apply position.
    Unique cover and pin combination eliminates piston binding that causes unexplained band failure
    Race-calibrated spring counteracts pin bias effect up to 275 psi
    Dual PTFE seal rings for better seal and low friction
    OE apply area
    Low-profile design ensures adequate clearance
    6061 Anodized billet aluminum cover
    Contents
    Supported Servo Cover
    Supported Servo Pin
    Servo Piston
    Return Spring
    Retaining Clip
    Gasket
    Cover O-Ring
    Pin O-Rings (2)
    1 extra
    Drain Plug
    Not shown
    Bolts (3)
    Not shown
    Pin Shims (3)
    Spring Shims (2)
    PTFE Piston Seal Rings (2)