A stuck or worn safety mode valve in GM 5L40-E, 5L50-E can result in the L/R clutch staying applied on a 1-2 upshift, causing a 1-2 bind-up condition. Wear at the 3-4 or 4-5 shift control valves allows signal and apply oil pressure to exhaust, preventing proper valve movement that causes flares, shift complaints and clutch distress. Reconditioning the bore and installing Sonnax oversized 3-4, 4-5 and safety mode valve kit 55211-14K restores the necessary hydraulic clearances required for proper valve function.

• Oversized valve kit allows elimination of bore wear
• Hardcoat anodized aluminum valves combat premature wear
• Annular grooves prevents future side load wear
• One valve kit can be used in any of three OE locations