Symptoms:

  • Burnt clutches
  • Pressure loss
  • Poor shift quality
  • Burnt converter
  • TCC apply & release concerns

Cause:

Wear of the OE clutch control valve bores can allow clutch apply fluid pressure to leak, resulting in burnt shift and TCC clutches that cause poor shift quality and converter issues.

Correction:

Installing the Sonnax drop-in clutch control valve with unique features seals leaking bores and restores proper hydraulic function.

8L45, 8L90

S2/S3/S4/TCC Clutch Control Valve Kit
Part No. 154740-11K

Fits any of 4 locations.


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

Burnt clutches, poor shift quality, overheated converters and TCC apply or release issues are common complaints with GM 8L45 and 8L90 transmissions. These issues can be caused by worn clutch control valves bores allowing valuable clutch apply fluid pressure to leak, reducing the force needed to apply the clutches. Sonnax S2/S3/S4/TCC Clutch Control Valve Kit 154740-11K is a drop-in valve with an added seal at the signal apply end and lengthened inboard spool at the clutch apply end that seals worn bores and restores proper function.

  • Hardcoat anodized aluminum valve combats premature wear
  • Lengthend valve spool utilizes unworn bore section to seal apply oil
  • Scarf cut seals prevent leaks at the signal apply end for proper clutch control
  • Drop-in Zip Valve™ parts install quickly and easily
Learn More About Zip Valve™ Drop-In Repairs

Sonnax bore sizing tool 154740-BST11 may be needed to ensure proper clearance between the valve and bore.

  • Valve
  • Spring, White S2, S3, S4
  • Spring, Red, selective TCC
  • Seal

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

GM 8L45, 8L90 Valve Body Layout

GM 8L45, 8L90 Valve Body Layout
  • 8L45, 8L90 S2/S3/S4/TCC Clutch Control Valve Kit 154740-11K
  • 8L45, 8L90 S2/S3/S4/TCC Clutch Control Valve Kit 154740-11K

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected. Outboard ports should be checked with solenoid installed. Inboard ports require solenoid removal and [154740-TL11] tool and can only check the OE valve.

8L45, 8L90 S2/S3/S4/TCC Clutch Control Valve Kit Vacuum Test Locations