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  • 4-5 Flare
  • 4-5 Harsh
  • Delayed engagement
  • Harsh engagement
  • K3 Clutch burned
  • No Forward


Bore wear at the K3 shift valve permits pressure loss that results in driveability concerns.


Recover hydraulic control and renew shift operation by reconditioning the bore and installing Sonnax oversized K3 shift valve kit.


Oversized K3 Shift Valve Kit
Part No. 88740-06K

You need this if... View Instructions

The K3 clutch in Mercedes 722.9 transmissions is applied in all gears except fourth and is controlled by the K3 shift valve. Oscillation of this valve in its bore causes excess wear in the aluminum casting, which allows crucial shift signal fluid to leak to exhaust. This can result in burnt K3 clutches, delayed or harsh engagement, 4-5 issues or loss of Forward and Reverse operation. Reconditioning the bore and installing Sonnax oversized K3 shift valve kit 88740-06K eliminates this wear for restored hydraulic integrity and K3 control in all ranges.

  • Hardcoat anodized aluminum valve combats premature wear
  • Annular grooves help center valve in bore to reduce future side-load wear
  • Matched spring provides precise calibration

Required tool kit F-46892-TL3 can also be used to install 46892-03.

  • Valve
  • Spring

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.

Mercedes 722.9 Valve Body Layout

Merc7229 vbl
  • 887740 06k combo
  • 887740 06k

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.

  • 88740 06k in test