Mercedes-Benz 722.9 no forward movement after overhaul - Transmission Digest

Mercedes-Benz 722.9 no forward movement after overhaul

The complaint

A 2007 Mercedes-Benz CLS550 with the 722.9 transmission has an after-overhaul complaint of no forward movement.

The cause

The B2 Brake Housing inner apply piston was installed upside down—refer to the image above, left.

The correction

The B2 Brake inner apply piston was re-installed in the correct position, after which forward movement returned, as seen in the above image, on the right. The B2 Brake is applied in first through fourth gears and holds the rear sun gear, which connects the output shaft to the rest of the gear train.

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