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  • Inadequate lubrication
  • TCC apply & release concerns
  • TCC codes


A sticking lockup relay control sleeve prevents TCC apply or release. Sleeve wear reduces converter pressure, overheating the fluid, and results in bushing and solenoid failure.


The tightly toleranced, drop-in replacement Sonnax valve and sleeve assembly restores proper hydraulic clearances, and uses upgraded materials to prevent wear.

55-50SN, 55-51SN

Lockup Relay Control Valve Kit
Part No. 59947-01K

Also fits AF 23/33 and RE5F22A units.

You need this if... View Instructions
  • Sleeve is manufactured from highly wear-resistant billet aluminum.
  • Valve is made from hard-coat anodized aluminum to prevent wear
  • Valve
  • Sleeve

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.

Aisin AW 55-50SN Valve Body Layout

Aw55 50sn vbl thumb

December 22, 2014

The Art of the Silver Bullet

Tory Royce

Topics: Diagnostics And Theory Shop Practices Rebuilding Tips Vacuum Testing Transmission GM Aisin AW 4L60-E Transmission 55-50SN Transmission

Read Now
  • 59947 01k combo
  • 59947 01k

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.

  • 59947 01k in test