Description
8L45 / 8L90 Shuttle Valve Kit, Sonnax 154740-09K.
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 drop-in shuttle valve kit 154740-09K has upgraded materials and minimal clearances to prevent wear and restore proper hydraulic control. We made the critical shuttle valve longer to improve sealing and durability of the assembly.
- Shuttle sleeve is manufactured from highly wear-resistant billet aluminum to prevent wear
- 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
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 shuttle valve assembly with upgraded materials and increased critical valve-to-sleeve sealing engagement to restore hydraulic integrity and prevent future wear.
