Printpartsummary
Symptoms:
  • B1 Clutch burned
  • B4 Clutch burned
  • C3 Clutch burned
  • Delayed Reverse
  • Low line rise in Reverse
  • Low Reverse boost
  • No Reverse
  • Reverse slip
Cause:

Persistent oscillation of OE steel boost valve within aluminum sleeve results in sleeve bore wear and loss of proper Reverse pressure.

Correction:

Recover hydraulic control and renew Reverse performance by installing Sonnax reverse boost valve kit.

U760E, U760F

Reverse Boost Valve Kit

Part No.

47740-38K

Reverse Boost Valve Kit
  • 47740-38k_combo

  • Reverse Boost Valve Kit

Small_47740-38k_combo Small_47740-38k

U760E, U760F

Reverse Boost Valve Kit

Part No. 47740-38K

  • Valve
  • Sleeve

Complaint:

  • B1 Clutch burned
  • B4 Clutch burned
  • C3 Clutch burned
  • Delayed Reverse
  • Low line rise in Reverse
  • Low Reverse boost
  • No Reverse
  • Reverse slip

Cause:

Persistent oscillation of OE steel boost valve within aluminum sleeve results in sleeve bore wear and loss of proper Reverse pressure.


Correction:

Recover hydraulic control and renew Reverse performance by installing Sonnax reverse boost valve kit.

Vehicles with Toyota/Lexus U760E and U760F transmissions may exhibit insufficient line rise in Reverse, delayed or slipping Reverse, and/or burned C3, B1, and B4 clutches. Continuous oscillation of OE steel boost valve within aluminum boost sleeve causes premature wear, creating a path for boost pressure to exhaust. Installing improved material Sonnax reverse boost valve kit 47740-38K restores the hydraulic integrity of the boost circuit to recover normal Reverse operation.

  • Restores proper line rise
  • Annular grooves help center valve in bore to reduce future side-load wear
  • Hardcoat anodized aluminum valve combats premature wear
  • Sleeve manufactured from highly wear-resistant aluminum to prevent excess wear and leakage

Related Parts

You need this if...

A vacuum test at the port indicated fails to hold at least 18 in-Hg.

  • Test Locations

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Valve Body Layouts

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.

Valve Body Layout Toyota U660E/F, U760E/F
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