Description
8L45 / 8L90 O-Ringed Shuttle Valve Kit, Sonnax 154740-30K.
Vehicles with a GM 8L45 or 8L90 transmission may exhibit high line pressure that results in harsh shifts, loss of cooler and lube flow and overheating of the transmission and converter. The shuttle valve oscillating continuously within the shuttle sleeve causes these problems, leading to excessive wear and providing a path for balance line pressure to escape at the pressure regulator valve. This prevents proper positioning of the pressure regulator valve and can keep it in the higher pressure position. In this position, the excess pressure is not allowed to bypass, and the converter/lube/cooler feed pressure is significantly reduced.
Sonnax O-ringed shuttle valve kit 154740-30K has upgraded materials, O-rings on sleeve to provide positive sealing, minimal clearances to prevent wear and restore proper hydraulic control. We made the critical shuttle valve longer to improve sealing and durability.
- Billet aluminum is used to manufacture the shuttle sleeve for wear resistance.
- O-Rings added for positive sealing to prevent critical fluid from cross-leaking
- Hardcoat anodized aluminum valve combats premature wear
- Critical valve spool made 30% longer than OE for added sealing and durability
- Drop-in Zip Valve™ parts install quickly and easily
- Valve
- Sleeve
- O-Rings (3) (1) Extra
Symptoms:
- High line pressure
- Harsh shifts
- Low cooler flow
- Loss of lube oil
- Overheated transmission & converter
Cause:
Wear of the OE pressure regulator shuttle valve sleeve due to continuous movement of the shuttle valve prevents proper line pressure control.
Correction:
Install the drop-in Sonnax O-ringed shuttle valve kit with upgraded materials and increased critical valve-to-sleeve sealing engagement to restore hydraulic integrity and prevent future wear.
