Symptoms:

  • 2-3 Flare
  • 4-5 Flare
  • Delayed Reverse
  • Reverse slip
  • 3-5-Reverse clutch burned
  • Ratio codes
  • Bind-up

Cause:

Oscillation of the 3-5-R clutch regulator valve causes bore wear that prevents proper hydraulic actuation of 3-5-R clutches.

Correction:

Recover hydraulic control and renew shift performance by reconditioning the bore and installing Sonnax oversized 3-5-R clutch regulator valve kit.

Warning:

Measure small spool on OE valve to determine correct Sonnax oversized 3-5-R clutch regulator valve kit.

  • 124740-26K replaces 1.35 ratio OE valve with .390" dia. spool.
  • 124740-21K replaces 1.83 ratio OE valve with .335" dia. spool.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1)

Oversized 3-5-R Clutch Regulator Valve Kit
Part No. 124740-26K

Replaces 1.35 ratio OE valve with .390" dia. small spool.


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

3-5-R clutches in Ford 6F50, 6F55 and GM first generation 6T70 and 6T75 units are applied in third, fifth and Reverse gears in conjunction with other clutch packs. As the 3-5-R clutch regulator valve oscillates and strokes over time, bore deterioration results, which prevents proper hydraulic control of the 3-5-R clutch pack. This can cause flares, slipping, erratic clutch apply timing, ratio codes, bind-ups, and burnt 3-5-R clutches. Reconditioning the bore and installing Sonnax oversized 3-5-R clutch regulator valve kit 124740-26K restores normal shift operation by re-establishing the hydraulic integrity of the 3-5-R circuit.

  • Replaces 1.35 ratio OE valve
  • Annular grooves help center valve in bore to reduce future side-load wear
  • Hardcoat anodized aluminum valve combats premature wear
  • Valve
  • End Plug

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.

GM Gen. 1 6T70, 6T75 Valve Body Layout

GM Gen. 1 6T70, 6T75 Valve Body Layout

Ford 6F50, 6F55 Valve Body Layout

Ford 6F50, 6F55 Valve Body Layout
  • 6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized 3-5-R Clutch Regulator Valve Kit 124740-26K
  • 6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized 3-5-R Clutch Regulator Valve Kit 124740-26K
  • 6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized 3-5-R Clutch Regulator Valve Kit 124740-26K 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.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized 3-5-R Clutch Regulator Valve Kit Vacuum Test Locations