REVERSE SERVO SPRING (MANUAL & BRAKE VALVE BODIES)

The Coan Racing COA‑22043 Reverse Servo Spring is a precision-engineered replacement component designed for TH400 transmissions equipped with manual or trans-brake valve bodies. Crafted from durable materials, this spring restores the essential tension in the reverse servo circuit, ensuring reliable and consistent reverse engagement. As drag racers and performance builders know, reverse servo functionality plays a key role in line pressure maintenance and gear transition integrity. Over time, weakening of the servo spring can lead to sluggish or unreliable reverse gear response.

Manufactured in the USA to Coan’s high-performance specifications, the COA‑22043 installs directly into the existing valve body without any case modifications. When refreshed as part of routine maintenance or during valve body rebuilds, this spring helps maintain firm reverse engagement, smooth hydraulic operation, and dependable staging performance, making it a simple yet vital upgrade for transmission longevity and consistent performance.