Description:
★ Manufacturer Part Numbers: 77987-01K, (2) 77998-03K
★ Interchange Part Numbers: S74927BK, S74927K
★ Dual seals stabilize and completely seal the bore, providing a tight seal even after thousands of cycles
★ Pinless design eliminates the possibility of pin leakage, and the additional length stabilizes the piston to prevent piston cocking

Part Number 77987-01K
★ Material: Aluminum
★ Dual Seal design
★ for GM 4L60-E, 4L65-E and 4L70-E units it is common for the plastic forward accumulator piston to wear or crack
★ This causes a loss of fluid, resulting in delayed engagement, slips, burnt clutches and/or bands
★ Repeated reciprocation of the accumulator piston causes the piston pin bore to wear, while fluid loss through the piston pin bore or cracks causes forward clutch to slip
★ The Pinless forward accumulator piston kit 77987-01K eliminates these problems
Package Includes:
★ Piston
★ D-Ring
★ PTFE Seal
★ 2x Steel balls for plugging existing pin bore in valve body

Part Number 77998-03K (2)
★ for GM units it is common to have poor shift quality, burnt bands or clutches due to accumulator piston wear
★ Repeated reciprocation of the accumulator piston causes wear at the piston pin bore interface
★ After this wear reaches a critical point, fluid loss through the piston pin bore cannot be compensated due to lack of pump volume
★ In addition, the piston can get cocked and gall the accumulator bore due to the pin bore wear or the spring bottoming out
★ To prevent these conditions in the 1-2 or 3-4 accumulator bores
★ Steel balls plug existing pin bore in case or cover
Package Includes:
★ D-Ring Viton
★ Pinless Accumulator Piston Aluminum
★ Seal PTFE
★ Steel Ball Size .312"
★ Steel Ball Size .236"
★ Note: In 200-4R applications, this kit can only be used in the 3-4 accumulator location