793D Off-Highway Truck Power Train: Torque Converter Sump, Gear Pump (Torque Converter and Transmission) & Magnetic Screen (Transmission)

1.-Torque Converter Sump

Torque converter sump

The torque converter sump is located behind the engine. Oil for the torque converter system and for the transmission hydraulic system is supplied by the torque converter sump.

The torque converter sump has two sight gauges. When the oil is cold, use the bottom sight gauge to check the oil level. When the oil is at operating temperature, use the top sight gauge to check the oil level. See the Operation and Maintenance Manual for lubricant viscosities and for refill capacities.

The torque converter sump, the transmission case reservoir, and the pump drive are vented to an air breather. The air breather is located on the vertical frame member on the right side of the truck.

2.-Gear Pump (Torque Converter and Transmission)

Location of the torque converter and transmission gear pump (1) Transmission lubrication section (2) Transmission charge pump section (3) Torque converter charge pump section(4) Transmission scavenge pump section

(1) Transmission lubrication section (2) Transmission charge pump section (3) Torque converter charge pump section (4) Transmission scavenge pump section (5) Pump prime orifice (6) Transmission charging hydraulic filter (7) Oil filter for Torque converter charge pump (8) Scavenge screen (9) Baffle (10) Torque converter sump(11) Oil cooler for the torque converter and for the transmission

The gear pump for the torque converter and for the transmission has four sections. The following sections are the four sections of the oil pump:

• Transmission lubrication section (1)
• Transmission charge pump section (2)
• Torque converter charge pump section (3)
• Transmission scavenge pump section (4)

The gear pump is driven by a gear on the torque converter.

Note: Each section of the gear pump receives oil that is shown in Illustration 2. All of the oil flows from torque converter sump (10) to the sections of the gear pump. The passages in the torque converter sump allow the sections to receive oil in the order that is shown. The purpose for this order does not allow air that is trapped in the torque converter at engine start-up to be purged through transmission charge pump section (3). The air will be purged through torque converter charge pump section (3) .

Oil from oil cooler (11) flows through torque converter sump (10) to transmission lubrication section (1). Oil from oil cooler (11) for the torque converter and for the transmission is the only oil that supplies transmission lubrication section (1). Transmission lubrication section (1) sends oil for the lubrication of the transfer gears and of the transmission. The excess oil leaks to the bottom of the transmission case.

Oil from torque converter sump (10) through scavenge screen (8) supplies all of the oil for transmission charge pump section (2). Transmission charge pump section (2) sends oil to the hydraulic filter for the transmission charging. Some of the oil from the transmission charging hydraulic filter flows to the lockup clutch and synchronizing valve. The rest of the oil flows to the transmission hydraulic control. The oil is used to activate the transmission clutches. Pump prime orifice (5) allows any air in the oil to escape to the circuit for transmission lubrication.

Supply oil for torque converter charge pump section (3) comes from two places. The supply oil from oil cooler (11) is more than the requirement for transmission lubrication section (1). The oil that is not used by transmission lubrication section (1) supplies torque converter charge pump section (3). The rest of the oil that is required for torque converter charge pump section (3) comes through scavenge screen (8). Torque converter charge pump section (3) sends the oil to torque converter oil filter (7). The oil then flows to the torque converter inlet relief valve. The oil then flows to the torque converter. A small amount of this oil lubricates the pump drive.

Transmission scavenge pump section (4) is located on the drive end. This pump section removes oil from the bottom of the transmission case. The oil flows through a magnetic screen to transmission scavenge pump section (4). The oil that is pulled in by the transmission scavenge pump section returns to the torque converter sump (10).

3.-Magnetic Screen (Transmission)

Construction of the magnetic screen (1) O-ring seal (2) Cover (3) Wave washer (4) Housing (5) Outlet (6) Magnets (7) Screen (8) Tube assembly(9) O-ring seal

Location of the magnetic screen(5) Outlet

The magnetic screen is fastened to the transmission case reservoir. Oil from the bottom of the transmission case goes through the inlet at the bottom. As the oil is drawn up through tube assembly (8), the oil flows through the openings that are between magnets (6). The magnets are installed on the tube assembly so that the same magnetic ends are next to each other.

As the oil flows over the magnets, metal particles are stopped by the magnets. The oil then flows through screen (7) to outlet (5). Other foreign particles are stopped as the oil flows through the screen. The particles are not allowed to go into the hydraulic system. The oil flows from outlet (5) to the transmission scavenge pump section.

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793D Off-Highway Truck Power Train: Torque Converter Sump, Gear Pump (Torque Converter and Transmission) & Magnetic Screen (Transmission) 2013-01-02T20:52:00-08:00 Rating: 4.5 Diposkan Oleh: Unknown