April 21, 2021
Symptoms:
- Burnt clutches
- Pressure loss
- Poor shift quality
Cause:
Wear of the OE clutch control valves can allow clutch apply fluid pressure to leak, resulting in burnt clutches that cause poor shift quality.Correction:
Installing the Sonnax drop-in S1/S5 clutch control valve with unique features seals leaking bores and restores proper hydraulic function.8L45, 8L90
S1/S5 Clutch Control Valve Kit
Part No. 154740-13K
Fits either of 2 locations.
-
Requires:
- 154740-TL11 (Recommended)
- 154740-BST13 (Recommended)
You need this if... View Instructions Find a Distributor
Burnt clutches and poor shifts are common issues 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 S1/S5 Clutch Control Valve Kit 154740-13K 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 prevents leaks at the signal apply end for proper clutch control
- Drop-in Zip Valve™ parts install quickly and easily
Sonnax bore sizing tool 154740-BST13 may be needed to ensure proper clearance between the valve and bore.
- Valve
- Spring
- 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
April 06, 2022
Diagnosing the Infamous GM 8L45, 8L90 3-4 Neutral: Check Your Solenoid Wiring Harness Assembly
Jim Mobley
August 10, 2023
Tips for Success with the GM Transmission Fast Learn Process
Jim Mobley
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.
