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  • Kickdown slip
  • Kickdown shock
  • 4th Slip
  • 5th Slip
  • 6th Slip
  • Code 734, 735, 729


Solenoid modulator valve or bore wear can result in excess or insufficient feed pressure to a variety of solenoids, adversely affecting shift functions.


The Sonnax oversized solenoid modulator valve kit corrects circuit pressure loss and restores control over solenoid modulator valve function.

TF-80SC, TF-81SC

Oversized Solenoid Modulator Valve Kit
Part No. 39741-18K

Fits either of 2 locations.

You need this if... View Instructions

The Aisin AW TF-80/81SC solenoid modulator valve establishes and controls feed pressure to a variety of solenoids. High or low solenoid feed pressure will adversely affect shift functions controlled by those solenoids. Wear at the inboard end of the solenoid modulator valve circuit causes excessive feed pressure. This floods the solenoids and reduces reaction time, resulting in harsh shifting and high line pressure. Wear at the outboard and mid-section reduces solenoid modulator pressure. This loss has the most effect on engagements and boost oil for line pressure rise. The Sonnax oversized solenoid modulator valve kit 39741-18K corrects wear in all areas, restoring pressure control and OE pressure calibration. This kit can be used in either of two valve body locations. The hardcoat anodized valve with annular groves and lengthened front spool combined with a wear-resistant sleeve offer precision control and extended service life.

  • Aluminum valve is hardcoat anodized to reduce wear and has added annular grooves for better centering in the bore
  • Highly wear-resistant sleeve and lengthened front valve spool provide 75% more sealing contact area
  • Valve
  • Sleeve
  • Spring
  • End Plug Use in TF-81SC Only

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

Aisin AW TF-81SC Valve Body Layout

Tf 81sc vbl thumb
  • 39741 18k combo
  • 39741 18k combo2
  • 39741 18k

You need this if...

A vacuum test at the ports indicated fail to hold at least 18 in-Hg

  • 39741 18k test