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  • Burnt brake clutches
  • Burnt clutches
  • Delayed engagement
  • Inadequate lubrication
  • Low pressure
  • Slips & flares
  • Soft shifts
  • TCC apply & release concerns
  • TCC codes


Loss of oil pressure due to worn components in critical oil circuits.


Recover hydraulic control and restore normal shift operation by installing Sonnax Zip Kit.


It has recently been determined that the late-style 6F35 may have differences that are not compatible with this Zip Kit. This kit is compatible with casting numbers RF9L8P-7A101 or RFBL8P-7A101 only. Please contact Sonnax Tech Support for detailed information.


Zip Kit®
Part No. 6F35-ZIP

RF9L8P-7A101 or RFBL8P-7A101 casting numbers only.

View Instructions

Sonnax Zip Kit 6F35-ZIP targets the root cause of multiple concerns by sealing critical circuit pressure losses in the Ford 6F35 valve body. The kit contains uniquely designed parts to prevent the loss of pressures within the main line, clutch apply control, solenoid feed, compensator feed and lockup control circuits. The kit also seals multiple circuits known to suffer from end plug leakage or poor checkball sealing. No special tools are required for installing these parts.

The Zip Kit quick guide provides clear and easy instructions on one sheet to get the unit sealed up and back on the road fast. In addition to general rebuilding tips and technical information, the technical booklet included in this kit contains vacuum testing information and locations at other key areas of the valve body.

  • No reaming required
  • Installs quickly with no special tools required
  • Uniquely designed parts address root causes of valve body concerns by sealing critical pressure circuits
  • Detailed technical booklet included with in-depth rebuild and inspection tips for comprehensive valve body repair
  • O-Ringed End Plug Kit
  • Checkballs (3) .250" dia.
  • TCC Regulator Valve Kit, Spring, Shuttle Valve, End Plug & O-Rings 2 O-rings, 1 extra
  • SSA Damper Piston & Spring
  • AFL Balance Plugs (2) Not Shown
  • Drill Bit Not Shown
  • Control Pressure Regulator Valve Kit
  • Solenoid Pressure Regulator Valve, Sleeve, Spring & Retainer Clip

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.

Ford 6F35 Valve Body Layout

Fd 6f35 vbl thumb

October 31, 2014

Ford 6F35 Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission Ford 6F35 Transmission

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February 19, 2015

Transmission Report: Sometimes the Best Tools are FREE!

Topics: Vacuum Testing Transmission Report Newsletters Diagnostics And Theory Transmission

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July 15, 2014

Zip Kit® Video - The first step in correcting common shift problems.

Topics: Diagnostics And Theory Transmission

Watch Now

  • 6f35 zip combo

The Sonnax ZIP KIT®

The First Step in Correcting Common Shift Problems

It's easy to restore and extend vehicle shift quality with Zip Kits. Uniquely designed Sonnax parts target the root cause of valve body complaints and stop critical circuit pressure losses in the most common problem areas of the transmission.

Learn More About Sonnax Zip Kits