OE end plugs are designed to prevent critical pressure loss by capping the bore, while also functioning as a 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. When excess wear occurs at the TCC valve end plugs, the result can be shifting problems and/or converter-related concerns in GM 4L80-E and 4L85-E transmissions.

Stop leaks and revive line pressure and TCC operation by installing Sonnax O-ringed end plug kit 34994-14K.

• Minimal end-plug-to-bore clearance with added O-ring for positive seal
• Reduces or eliminates leakage in eroded OE bores
• Drop-in Zip Valve^™ parts install quickly and easily