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A/T - Harsh Shifts or Erratic Shift Quality

TECHNICAL BULLETIN # 259

DATE: 1994

TRANSMISSION: 722.3, 722.4, 722.5

SUBJECT: Harsh Shifts or Erratic Shift Quality

APPLICATION: Mercedes Benz, Porsche

722.3, 722.4, 722.5 Mercedes Benz, Porsche Harsh Shifts or Erratic Shift Quality




The rubber cover on a Mercedes Benz modulator is more than a protective dust cover. It is actually a part of the vacuum containment system. If the cap is missing, poor fitting, cracked or otherwise leaking, the shifts may be harsh or erratic.

The cap and modulator assembly can be tested with a hand held vacuum pump attached to the vacuum hose fitting. It must be able to hold at least 14 inches of vacuum.

The part number for the cap is 126 277 00 81.

It can be purchased at your local Mercedes Benz dealer.