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Accumulator Piston Kit
Accumulator Piston Kit
Accumulator Piston Kit For 4L60E 4L65E 4L70E Transmission Pinless 1-2 3-4
Accumulator Piston Kit For 4L60E 4L65E 4L70E Transmission Pinless 1-2 3-4
Replace Part Number
77987-01K
7798-03K
In 200-4R applications, this kit can only be used in the 3-4 accumulator location.
Fitment1
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.
Fitment 2
For 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. Our 77987-01K dual seals stabilize and completely seal the bore and provide 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.
speciafication
Name:Pinless Forward Accumulator Piston Kit Color: Silver Material: Aluminum Alloy Package Size: see pic
Package contents 77987-01K: 1 x Piston with seal rings 2 x Steel balls 77998-03K (2PC) 2 x Piston with seal rings 4 x Steel balls
Austin Dickerson
Reviewed in the United States on February 2, 2025
the seals dont fit right you push it in and it gets stuck so stuck in fact the springs wont push it back up not saying it wont work as intended but am going to have to order some from sonnox now. I'll work if you got to save few dollers it was cold when I put it in. It worked better when the air temp got to around 68
John Lynn
Reviewed in the United States on January 31, 2025
Very good quality reproductions, fit right and work flawlessly. Have purchased in the past and will purchase again in the future.
John S.
Reviewed in the United States on June 28, 2024
Some might say that if you don't know what your doing then you probably shouldn't; I disagree. I watched a video from another mfr to perform this upgrade. I will say that everything works!
k nofziger
Reviewed in the United States on November 30, 2024
only issue is the steel balls to replace the pins are the wrong size. I just cut the end of the pins off and staked them in place
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