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  • Clutch & band failures
  • Non-adjustable (high) throttle pressure
  • 1-2 Flare
  • 2-3 Flare
  • 2-1 Clunk
  • Neutral after 4th
  • No 4th
  • Harsh Reverse
  • No Forward
  • Delayed engagement
  • TCC cycling
  • TCC surge
  • Code 741, 1741, 1744
  • TCC apply & release concerns
  • TCC codes & overheating



The parts in this Sure Cure kit repair and restore key areas most prone to TCC-related transmission problems and other issues affecting shift quality.

4F50N, AX4N

The Sure Cure® Kit
Part No. SC-AX4N

View Instructions

Sonnax Sure Cure Kits combine the best Sonnax products into one box, offering rebuilders a convenient and cost-effective way to address common transmission problems. These kits simplify ordering, stocking and estimating job costs, and include easy-to-read, step-by-step instructions that cover the inspection and repair of the most critical areas of the unit, and even a reference list of rebuilding specifications.

This kit is fully compatible with all AX4N units. For AXODE and AX4S units, use Sure Cure kit SC-AXODE.

*Currently 96206-BST is no longer in production but may be available from distributor inventory.

  • Relief Valve, Low Radius (2)
  • Oversized Converter Regulator Valve Kit requires tool kit 96201-TL3 or F-96201-TL23 & VB-FIX
  • Oversized Solenoid Regulator Valve Kit requires tool kit 96201-TL2
  • Pump Slide Pin
  • Boost Valve Kit
  • Oversized Bypass Clutch Control Valve Kit requires tool kit 96206-TL
  • Forward Control Valve Kit Patent No. 6,736,747, Sonnax recommends bore sizing tool 96206-BST*

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 AX4N/4F50N Valve Body Layout

Ford ax4n 450n

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

Read Now

  • Sc ax4n

Sonnax Sure Cure® Kits

Comprehensive Kit for Big Problems You Don't Want Back

Knowing exactly what parts to replace in troublesome transmissions is an ever-increasing challenge, but Sonnax Sure Cure kits solve this problem for you. Each kit is a comprehensive reconditioning package featuring the best Sonnax products developed to help rebuilders restore and enhance transmission performance.

Learn More about Sonnax Sure Cure Kits