Fits For --
1993-2018 4L60E: 1-2 & 3-4 Accumulator Piston (.310" Pin Diameter) (Pinless Design)
2001-2018 4L70E: 1-2 & 3-4 Accumulator Piston (.310" Pin Diameter) (Pinless Design)
2001-2018 4L65E: 1-2 & 3-4 Accumulator Piston (.310" Pin Diameter) (Pinless Design)
1981-1990 TH200-4R: Only 3-4 Accumulator Piston (.310" Pin Diameter) (Pinless Design)

1982-1993 TH700-R4: 1-2 & 3-4 Accumulator Piston (.310" Pin Diameter) (Pinless Design)

Why you choose us
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, we offer pinless accumulator piston kit 77998-03K.