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Symptoms:
  • Damaged valve body casting
  • Delayed Forward
  • Delayed Reverse
  • Forward or Low/Reverse clutch distress
  • Low line pressure upon engagement
Cause:

The OE valve is subjected to high side loading, which wears out the bore and reduces pressure to the clutch.

Correction:

The Sonnax drop-in replacement valve is slightly oversized, has extended spool lengths, stabilization flats, annular grooves and a reduced spring load. This valve eliminates clutch pressure loss as well as continued bore wear. One valve and spring work for either the forward or reverse abuse location.

4L60-E, 4L65-E, 4L70-E

Forward & Reverse Abuse Valve Kit

Part No.

77754-35K

Forward & Reverse Abuse Valve Kit
  • 77754-35k_combo

  • Forward & Reverse Abuse Valve Kit

  • 77754-35k_details

Small_77754-35k_combo Small_77754-35k Small_77754-35k_details

4L60-E, 4L65-E, 4L70-E

Forward & Reverse Abuse Valve Kit

Part No. 77754-35K

  • Valve
  • Plug
  • Spring

Fits in either of two locations

Complaint:

  • Damaged valve body casting
  • Delayed Forward
  • Delayed Reverse
  • Forward or Low/Reverse clutch distress
  • Low line pressure upon engagement

Cause:

The OE valve is subjected to high side loading, which wears out the bore and reduces pressure to the clutch.


Correction:

The Sonnax drop-in replacement valve is slightly oversized, has extended spool lengths, stabilization flats, annular grooves and a reduced spring load. This valve eliminates clutch pressure loss as well as continued bore wear. One valve and spring work for either the forward or reverse abuse location.

Continuous oscillation of the forward and reverse abuse valves creates bore wear, allowing clutch feed pressure to exhaust. This reduced clutch pressure causes slippage and burn-up. The Sonnax drop-in replacement valve is slightly oversized and has extended spool lengths to provide additional sealing contact area. The stabilization flats on the inboard end of the spool maintain OE flow, but provide continual valve support while stroking. Annular grooves have been added to prevent side loading and a new spring is provided for the modified valve length. This kit fits either the forward or reverse abuse location and includes a replacement bore plug.

  • Kit raises clutch pressure slightly to prevent slippage and burn-up, an advantage for heavy-duty, plowing or repetitive forward-reverse maneuvers.
  • Eliminates leakage of clutch feed pressure to the exhaust port at the spring pocket.
  • One valve and spring combination works for either forward or reverse abuse locations.
  • No reaming is required for the slightly oversized drop-in replacement valve.
  • Includes replacement abuse bore plug

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Contact a Sonnax Distributor to purchase this part.