Mercedes Transmission Oil Pump O-Ring - DPH 0169971448

The Pump O-Ring prevents transmission fluid from leaking out of the bellhousing. With age this o-ring tends to harden and seal poorly which will cause leaks out of the front pump. Although it is not easy to diagnose a transmission pump o-ring leak, if the transmission leak appears to occur from the bellhousing area and leaks when the transmission is not operating such as a car sitting overnight, this could be a result of a pump o-ring leak. Unlike earlier iterations of Mercedes transmissions the pump cannot be removed without splitting the bellhousing from the transmission case. If you are performing a pump replacement, consider replacing all common wear items, gaskets and seals.

The Mercedes 722.6 transmission or 5GTronic is one of the most popular Mercedes transmissions in operation used from 1996-2015. This transmission was used across various models from the C-Class up to the SLR McLaren supercar. In addition, it was also installed in various Porsche 996 models, supercharged Jaguars, and various Chrysler/Jeep/Dodge applications. This is an electronically controlled transmission and most common failures are electronic on these models. Shift modules which are integral to the shift lever assembly commonly fail when they are inadvertently exposed to soft drinks and coffee. Conductor Plates commonly fail when the speed sensors stop functioning. These failures typically lead to erratic shifting, a check engine light and a transmission stuck in limp mode.

The most common fluid leak is at the 13 PIN electrical connector, if left unattended, it is not uncommon for fluid to wick its way up to the transmission control module. Good practice is to change the fluid level every 40k miles, and periodically check for leaks. This transmission is not equipped with a dipstick and requires a special service tool to verify fluid level. When properly maintained, the transmission should last the life of the vehicle.