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  • Burnt brake clutches
  • Burnt clutches
  • Delayed Reverse with harsh engagement
  • Harsh Reverse
  • Harsh shifts
  • Forward slip
  • Flare shifts


Wear at the accumulator piston bores in the valve body or on the critical diameters of the accumulator pistons allows apply oil to exhaust.


The Sonnax hardcoat anodized accumulator piston incorporates an O-ring for positive sealing and annular grooves for better centering and wear prevention.

U660E, U660F, U760E, U760F

B1, B2, B3, C2 Accumulator Piston Kit
Part No. 47740-11K

You need this if... View Instructions

Wear at the accumulator bores or on the critical diameters of the accumulator pistons in the Toyota/Lexus U660E/F, U760F/F transmission is very common. The B1, B2, B3 and C2 accumulator pistons are all the same size and are used during apply of the clutches and brakes to ease the engagement of the apply component. Wear at the valve body bore allows clutch/brake apply oil to exhaust, resulting in harsh or delayed apply of the clutch or brake, burned clutches and brakes, or slipping and flares in the associated gears.

Sonnax B1, B2, B3, C2 accumulator piston kit 47740-11K incorporates an O-ring for positive sealing, even in worn bores. This one kit will work in any of the four bores.

  • No machining or special tools required
  • O-ring provides positive seal even in worn bores
  • Annular grooves provide better piston centering and reduce wear

Fits in any of four locations.

  • Piston
  • O-Rings (2) 1 extra

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 U660E/F, U760E/F Valve Body Layout

U660ef vbl thumb

December 09, 2013

Toyota/Lexus U660E, U660F, U760E, U760F Identification Guide

Topics: Identification Guides Transmission Toyota/Lexus U760F Transmission U660F Transmission U760E Transmission U660E Transmission

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December 30, 2013

Toyota/Lexus U660E/F Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission Toyota/Lexus U660F Transmission U660E Transmission

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  • 47740 11k combo
  • 47740 11k
  • 47740 11k details

You need this if...

A vacuum test at the port indicated fails to hold at least 18 in-Hg, or if visual wear in bore or on the accumulator piston is detected.

  • 47740 11k test