Symptoms:

  • Burnt clutches
  • Delayed engagement
  • Erratic line pressure
  • Low line rise
  • Low Reverse boost
  • No Reverse
  • Poor shift quality
  • Reverse slip
  • Soft shifts

Cause:

OE boost sleeve and pressure regulator bore deterioration allows pressure loss that leads to driveability concerns.

Correction:

Recover hydraulic control and renew shift performance by reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit.

U341E, U341F

Oversized Pressure Regulator & Boost Valve Kit
Part No. 37740-03K


You need this if... View Instructions Find a Distributor

Toyota/Lexus vehicles equipped with U341E and U341F transmissions may exhibit insufficient line rise, resulting in delayed engagement, slipping in Reverse, poor shift quality and burnt clutches. These troubles can often be caused by wear in the OE pressure regulator valve bore and/or boost sleeve, which allows pressure escape that causes driveability concerns. Reconditioning the bore and installing Sonnax oversized pressure regulator and boost valve kit 37740-03K eliminates pressure loss and revives line rise and shift quality in all ranges.

  • Lengthened critical spools provide added stability and wear prevention
  • Annular grooves help center valves in bore to reduce side-load wear
  • Hardcoat anodized aluminum valves combat premature wear
  • Shims allow adjustable OE base line pressure to be matched
  • Pressure Regulator Valve
  • Boost Valve
  • Boost Sleeve
  • Shims (2)

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.

Toyota/Lexus U341E/F Valve Body Layout

Toyota/Lexus U341E/F Valve Body Layout
  • U341E, U341F Oversized Pressure Regulator & Boost Valve Kit 37740-03K
  • U341E, U341F Oversized Pressure Regulator & Boost Valve Kit 37740-03K
  • U341E, U341F Oversized Pressure Regulator & Boost Valve Kit 37740-03K details

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

U341E, U341F Oversized Pressure Regulator & Boost Valve Kit Vacuum Test Locations