Boost Valve Kit Sonnax 4R44E 4R55E 5R44E 5R55E

Boost Valve Kit 4R44E, 4R55E, 5R44E, 5R55E From Sonnax Ford 4R44E, 4R55E, 5R44E, and 5R55E units are often plagued by issues such as soft shifts, delayed Reverse, poor modulator control, and/or low line pressure in Reverse. A worn boost valve is a frequent culprit, allowing Reverse and/or TV pressure to cross leak or exhaust. Sonnax provides two tailored replacement boost valve kits for these units: the OE ratio boost valve kit 37947-01K and the increased ratio boost valve kit 37947-03K. The 37947-01K maintains OE spool ratios, restoring line rise to stock condition, while the 37947-03K assembly is designed with increased ratios to achieve slightly higher line pressures. Key Features: Sleeves are crafted from a highly wear-resistant aluminum alloy, ensuring durability and longevity Hardcoat anodized aluminum valve is designed to combat premature wear Tight tolerances are maintained to restore the hydraulic integrity of the assembly Kits are engineered to improve engagement, addressing