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  • Burnt clutches
  • Pressure loss
  • Shift concerns
  • TCC apply concerns


End plug wear allows valuable actuator/solenoid feed pressure to leak at the various regulator valve bores. When the clutch bypass end plug leaks, Reverse pressure suffers.


Recover hydraulic control and renew critical circuit pressures by installing Sonnax O-ringed end plug kit.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1)

O-Ringed End Plug Kit
Part No. 124740-02K

You need this if... View Instructions

OE end plugs are designed to prevent critical pressure loss by capping the bore, while also functioning as a spring or valve stop. Repetitive spring motion, valve impact and fluid pressure variations cause wear between the end plug and bore mating surface, allowing vital pressure to escape the circuit.

Ford 6F50, 6F55 and GM first generation 6T70, 6T75 valve bodies have end plugs at the various clutch regulator valve bores which are susceptible to this wear. When actuator/solenoid feed pressure is allowed to leak due to plug deterioration, various shift concerns and burnt clutches will result in the affected circuit. Wear at the TCC regulator and clutch bypass valve end plugs allows valuable oil loss that leads to driveability concerns. Eliminate leaks and restore hydraulic integrity by installing Sonnax O-ringed end plug kit 124740-02K.

  • Minimal end-plug-to-bore clearance with added O-ring for positive seal
  • No reaming or special tools required
IDFord 6F50, 6F55 LocationsGM 6T70, 6T75 (Gen. 1) Locations
1 Pressure Regulator Valve Pressure Regulator Valve
2 Isolator Valve Isolator Valve
3 Multiplex Manual Valve Clutch Select Solenoid Valve #3
4 Multiplex Shift Valve Clutch Select Solenoid Valve #2
5 Direct Clutch Regulator Valve 3-5 Reverse Clutch Regulator Valve
6 Intermediate Clutch Regulator & Gain Valve 2-6 Clutch Regulator & Gain Valve
7 TCC Regulator Apply Valve TCC Regulator Apply Valve
8 L/R Overdrive Clutch Regulator Valve L/R 4-5-6 Clutch Regulator Valve
9 Forward Clutch Regulator Valve 1-2-3-4 Clutch Regulator Valve
  • End Plugs (9)
  • O-Rings (14) 5 Extra

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 6T70 (Gen. 1), 6T75 (Gen. 1) Valve Body Layout

Gm 6t70 6t75 vbl

November 06, 2014

Ford 6F50, 6F55 Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission Ford 6F55 Transmission 6F50 Transmission

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  • 124740 02k in combo
  • 124740 02k

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.

  • 124740 02k in test