• Gear ratio & solenoid codes
  • Lube failures
  • Poor lube oil control
  • Converter concerns
  • Reduced converter clutch life
  • TCC apply & release concerns
  • Burnt converter


Wear at various OE end plugs allows critical circuit leakage, resulting in drivability concerns.


Prevent circuit leakage and restore normal operation by installing Sonnax drop-in O-ringed end plug kit.

8L45, 8L90

O-Ringed End Plug Kit
Part No. 154740-17K

You need this if... View Instructions Find a Distributor

OE end plugs are designed to prevent critical pressure loss by capping the bore, while also functioning as a spring or valve stop. Repetitive spring motion, valve impact and fluid pressure variations cause wear between the end plug and bore mating surface, allowing vital fluid to escape the circuit.

Wear at various OE end plugs in GM 8L45 and 8L90 transmissions allows critical leakage at the following circuits, default override, lube flow regulation, and converter lockup/release. These pressure losses impair control of clutches, effect lube flow regulation and critical converter control.

Put an end to leaks, restore hydraulic integrity and renew shift operation by installing Sonnax O-ringed end plug kit 154740-17K.

  • Minimal end plug-to-bore clearance with added O-ring for positive seal
  • Reduces or eliminates leakage in eroded bores
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs
  • End Plugs (3)
  • O-Rings (4) 1 Extra
  • 8L45, 8L90 O-Ringed End Plug Kit 154740-17K
  • 8L45, 8L90 O-Ringed End Plug Kit 154740-17K

You need this if...

End plug deterioration or bore wear is visually detected in any of the (3) locations.

8L45, 8L90 O-Ringed End Plug Kit Vacuum Test Locations