USA Standard Gear ZMZFS6-K1 Manual Transmission ZF Synchro Spring and Key Kit - S6-650 1st 2nd

The USA Standard Gear ZMZFS6-K1 is a complete synchronizer spring and key kit designed specifically for the ZF S6-650 6-speed manual transmission. This kit includes all the necessary springs and keys to rebuild or repair the 1st and 2nd gear synchronizer assemblies, restoring smooth and reliable shifting performance.

Key Features:

• Direct replacement synchronizer components for ZF S6-650 transmissions
• Includes springs and keys for both 1st and 2nd gear synchronizers
• Manufactured to OEM specifications for proper fit and function
• Essential components for transmission rebuilds and synchronizer repairs
• Quality-manufactured by USA Standard Gear for reliable performance

The ZF S6-650 transmission is commonly found in Ford F-Series Super Duty trucks and other heavy-duty applications. This synchro spring and key kit is an essential component set for transmission rebuilders and shops performing manual transmission overhauls. When synchronizer springs and keys wear out, they can cause grinding, difficult shifting, or gear clash—replacing these components restores proper synchronizer engagement and extends transmission life.