Symptoms:
- Burnt clutches
- Pressure loss
- Poor shift quality
- Burnt converter
- TCC apply & release concerns
Cause:
Wear of the OE clutch control valve bores allows clutch apply fluid pressure to leak, resulting in burnt clutches and TCC apply and release concerns that cause poor shift quality.Correction:
Reconditioning the bore and installing Sonnax oversized S2/S3/S4/TCC clutch control valve kit restores proper hydraulic function.Warning:
Later-design valve bodies have updated the S4 valve to a single .531" dia. size. The Sonnax valve cannot be used in this location or shift complaints will occur.
8L45 | 8L90
Oversized S2/S3/S4/TCC Clutch Control Valve Kit
Part No. 154740-43K
Fits any of 4 locations, S4 location fits ’18-earlier only.
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Tooling:
- F-154740-TL43
- VB-FIX
You need this if... View Instructions Find a Distributor
Burnt clutches, poor shift quality and TCC apply or release issues are common complaints with GM 8L45 and 8L90 transmissions. These issues can be caused by worn clutch control bores allowing valuable clutch apply fluid pressure to leak, reducing the force needed to apply the clutches. Reconditioning the bores and installing Sonnax oversized S2/S3/S4/TCC clutch control valve kit 154740-43K restores proper function.
- Hardcoat anodized aluminum valve combats premature wear
- Lengthened valve spool utilizes unworn bore section to seal apply oil
- Oversized valve and replacement spring maintains OE functions and pressures
- Valve
- S2, S3, S4 Spring White
- TCC Spring Red
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.
Related Sonnax Parts
Required
Recommended
8L45 • 8L90
The Sure Cure® Kit SC-8L45-8L90
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Helps cure:
- Pressure loss
- Erratic line pressure
- Gear ratio & solenoid codes
- Burnt transmission components
- TCC apply & release concerns
- Poor shift quality
- Lube failures
- Damaged valve body casting