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  • Overheated clutch
  • Overheated band
  • Low line rise
  • Uncontrollable shift timing
  • TV pressure imbalance


The throttle valve plug wears the sleeve, allowing throttle valve feed oil to leak past the plug and exhaust.


The replacement kit includes a tightly toleranced O-ringed sleeve manufactured to resist excessive wear.


Throttle Valve Plug Kit
Part No. 76989K

O-ring style

View Instructions

Uncontrollable throttle pressure due to oil loss is a common complaint in vehicles with an AOD transmission. This results in low line pressure and poor throttle and shift timing adjustments. The hardened steel throttle valve plug continuously reciprocates within the aluminum throttle valve sleeve, wearing the inside diameter of the sleeve. This wear allows throttle valve feed oil to leak past the plug and exhaust, resulting in poor line rise. This excessive leakage can be eliminated by installing Sonnax throttle valve plug and O-ringed sleeve kit 76989K.

  • The throttle valve sleeve is manufactured from high-quality aluminum to prevent wear.
  • O-rings added to the outside diameter of the sleeve prevent feed oil from escaping past the valve body bore.
  • Steel plug has been tightly toleranced to allow minimum clearance with the inside diameter of the sleeve, thus restoring the hydraulic integrity of the assembly.
  • Plug
  • Sleeve
  • O-Rings (2)

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

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  • 76989k combo
  • 76989k