Lubricating pressure - RA27007229130X(27-9130)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Lubricating Pressure Flow Diagram (4-Speed Transmission)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

4-speed transmission: lubrication system shown with brake band B2 applied

Fig 2: Lubricating Pressure Flow Diagram (5-Speed Transmission)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

5-speed transmission: lubrication system shown with brake band B2 applied

The pressurized lubricating oil flows through the torque converter and also the oil cooler where it is cooled before being passed again to mechanical section of the transmission. This ensures that the transmission temperature is maintained within permissible limits. The lubricating oil flows from the discharge edge (h) of the working pressure control valve (26) to the torque converter, from there to the oil cooler and back again to the transmission. It flows to the points at which it is needed for cooling and lubrication through the passages and drillings provided in the housings, shafts and gears.

The lubricating pressure is limited at the lubricating pressure valve (64). The excess oil flows back into the suction passage of the primary pump. The lubricating pressure varies between 3.5 and 5.0 bar in the upper engine speed range.

In 4th gear, the spring chamber of the shift pin (35) is pressureless as soon as brake band B2 has released. The lubricating pressure at the opposite end face surface raises the shift pin (35) against the spring force and a partial quantity of the lubricating oil flows back directly into the suction passage of the primary pump. The quantity of oil flowing to the lubricating points in the transmission is reduced as only a slight quantity of lubricating oil is required for the planet gear sets rotating in a block. The rear planet gear set for 5th gear requires an additional quantity of lubricating oil. This flows through a direct connection from the valve body assy via the bottom cover to the inter mediate shaft. The lubricating pressure is monitored at the lubricating pressure measuring valve (94) as part of the standard monitoring program.