Product Description
Symptoms:
- Burnt clutches & bands
- Poor shift quality
Cause:
Wear at the piston pin bore due to repeated reciprocation.
Correction:
The Sonnax patented pinless design with dual seals stabilizes the piston in the bore and provides improved sealing characteristics. Use of the Sonnax part eliminates the need for the pins.
200-4R, 4L60, 4L60-E, 4L65-E, 4L70-E
Pinless Accumulator Piston Kit
Part No. 77998-03K
- Pinless Accumulator Piston Aluminum
- D-Ring Viton®
- Seal PTFE
- Balls (2) Steel
In 200-4R applications, this kit can only be used in the 3-4 accumulator location.
In GM 200-4R, 4L60 and 4L60-series 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, Sonnax offers pinless accumulator piston kit 77998-03K.
- Pinless design eliminates the possibility of pin bore leakage and the additional length stabilizes the piston to prevent piston cocking
- Dual seals stabilize and completely seal the bore and provide a tight seal even after thousands of cycles
- Steel balls plug existing pin bore in case or cover
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Product Reviews
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1/2 acumulator
this pinless system works amazing. I bought a monster transmission and on my 3rd rebuild of the 4l60e I had a really hard shift they said it was the shift kit they installed well sick of sending it back to be dissatisfied so I fixed it myself bought this pinless accumulator for my 1/2 and installed with better springs and replaced the plastic garbage they sent it with with better. Very pleased
