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  • Severe wear at accumulator bores
  • Low clutch oil pressure
  • Low TCC pressure
  • Low EPC pressure


Since the length of the OE accumulator piston is short relative to its diameter, the effect of incidental side loading forces is increased. This characteristic, combined with relatively strong nested springs and the soft material of the valve body, results in severe wear. This extreme wear is noticeable in many low mileage units.


Installing the Sonnax sleeve creates a new accumulator bore surface in severely worn valve bodies. Our improved sleeve design provides increased wear resistance and sealing. The kit comes with an assortment of custom-designed springs which allow you to duplicate and restore OE accumulator calibration and response.

TF-60SN, TF-80SC, TF-81SC, TR-60SN

Accumulator Piston Kit
Part No. 39741-42K

You need this if... View Instructions

Worn-out accumulator piston bores in listed Aisin AW 6-speed units allow pressurized transmission fluid to leak past the accumulator piston to the sump. These leaks can result in a flare at upshift, delayed engagement, poor line rise or clutch failure. The Sonnax accumulator piston kit 39741-42K will restore a worn accumulator bore and correct leakage problems.

  • Salvages valve bodies with severe accumulator bore wear
  • O-Ring seal improves piston response
Paint Color Dimensions Paint Color Dimensions
Yellow O.D.= .618" (15.7mm) Yellow O.D.= .520" (13.21mm)
Wire Dia. = .078" (1.98mm) Wire Dia. = .068" (1.73mm)
Yellow O.D.= .412" (10.46mm) Yellow O.D.= .345" (8.76mm)
Wire Dia. = .054" (1.37mm) Wire Dia. = .047" (1.19mm)
No Paint O.D.= .632" (16.05mm) No Paint O.D.= .523" (13.28mm)
Wire Dia. = .083" (2.11mm) Wire Dia. = .070"(1.78mm)
Gray/Blue O.D.= .429" (10.90mm) Gray/Blue O.D.= .336" (8.53mm)
Wire Dia. = .063" (1.60mm) Wire Dia. = .051" (1.30mm)

This kit can be modified to fit other variations of the AW 6-speed applications by modifying the sleeve length. Can be used in 5 locations.

  • Piston
  • Sleeve
  • O-Ring
  • Springs (4) Selective

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.

Aisin AW TF-80SC Valve Body Layout

Tf 80sc vbl thumb

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

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  • 39741 42k combo tf 60sn
  • 39741 42k combo tf 80sc
  • 39741 42k combo tf 81sc
  • 39741 42k combo tr 60sn
  • 39741 42k parts

You need this if...

The accumulator bore and piston wear is severe enough that Sonnax accumulator piston kit [15741-14K] will not function in the worn bore.