sonnax-black Facebook-color LinkedIn-color maillink printlink r_and_r_only SERVOFIX-logo-web Twitter-color VBFIX-logo-web video-logo-web warranty_only Youtube-color


  • Clutch distress
  • 4-5 Concerns
  • 1-2 Bind-up
  • 3-4 Flare


Valve bore wear results in loss of apply oil, sluggish valve movement and sticking valves causing shift complaints and clutch distress.


Install the Sonnax oversized valve kit that fits in any of the three locations (3-4 and 4-5 shift valve, safety mode valve) after refurbishing the bore to eliminate bore wear and sticking valves.

5L40-E, 5L50-E

Oversized 3-4, 4-5 & Safety Mode Valve Kit
Part No. 55211-14K

You need this if... View Instructions

A stuck or worn safety mode valve in the 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. Sonnax has developed an oversized valve and control valve kit that, when installed in a refurbished bore, restores the necessary hydraulic clearances required for proper valve function. This kit 55211-14K can be used in the 3-4 and 4-5 shift valve bores as well as the safety mode valve location.

  • Oversized valve kit allows elimination of bore wear
  • Hard-coat anodized aluminum valves with annular grooving prevent future wear
  • One valve kit can be used in any of three OE locations

This kit can be used in any of three locations. If using in the safety mode valve location, the control (small) valve is not used.

  • Shift Valve
  • Control Valve
  • Spring

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 5L40-E, 5L50-E Valve Body Layout

Gm 5l40 e vbl thumb

November 24, 2015

GM 5L40-E, 5L50-E Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission GM 5L50-E Transmission 5L40-E Transmission

Read Now
  • 55211 14k combo2
  • 55211 14k combo3
  • 55211 14k combo1
  • 55211 14k

You need this if...

A vacuum test at ports indicated (Figure 1) fails to hold indicated minimum vacuum amount.

  • 55211 14k test