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| Illustration 1 | g01220898 |
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Location of power train oil pump | |
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| Illustration 2 | g01220899 |
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Power train oil pump with section views (1) Pump inlet (transmission scavenge oil) (2) Pump outlet (transmission and torque converter scavenge oil) (3) Pump inlet (torque converter scavenge oil) (4) Pump outlet (transmission and controls) (5) Pump outlet (torque converter and lubrication) (6) Pump inlet (transmission and torque converter charging section) (7) Gear (8) Gear (9) Gear (10) Cover (11) Gear (12) Gear (13) Gear | |
The power train oil pump is mounted on the front of the bevel gear case. The pump is driven by an auxiliary drive shaft from the engine. The bevel gear case is the sump for the power train hydraulic system.
The transmission oil pump is a gear pump that contains three sections.
Section (A) - Torque converter charge pump section
Section (B) - Transmission charge pump section
Section (C) - Torque converter and transmission scavenge section
A single auxiliary drive shaft from the engine drives all three sections.
Torque Converter Charge Pump Section
Section (A)
Section (A) draws oil from the bevel gear case through a screen and a magnet. The oil enters the pump through pump inlet (6).
Within the pump, oil passes between gear (9) and gear (11). An auxiliary drive shaft from the engine drives gear (9). Gear (9) turns idler gear (11). The oil exits at pump outlet (5).
Next, oil flows to the lubrication distribution manifold. The lubrication distribution manifold sends a portion of the oil to the torque converter. The rest of the oil is sent as lubrication for the steering differential and brakes and the transmission.
The oil for operation of the torque converter exits through the outlet relief valve. The oil then flows to the oil cooler. The cooled oil is sent back to the lubrication distribution manifold. The oil is combined with the oil that bypassed the torque converter.
The oil that is combined at the lubrication distribution manifold flows to the transmission and the steering differential and brakes. This oil serves as lubrication for the transmission and the steering differential and brakes before returning to the bevel gear case. A small portion of the flow is diverted from the torque converter inlet in order to lubricate the gears of the pump drive and the bearing.
The lubrication distribution manifold normally sends oil from section (A) to the torque converter and to the steering differential and brakes. A portion of this oil is also sent to the transmission for lubrication.
Transmission Charge Pump Section
Section (B)
Section (B) draws oil from the bevel gear case through a screen and through a magnet. The oil enters the pump through pump inlet (6).
Within the pump, oil passes between gear (8) and gear (12). An auxiliary drive shaft from the engine drives gear (8). Gear (8) turns idler gear (12). The oil exits at pump outlet (4). Then, the oil flows to both the brake control valve and the transmission controls.
At the transmission controls, the oil that flows past the main relief valve provides part of the lubrication and the cooling for the transmission and the bevel gear case. Oil from section (B) is primarily used to control the brakes and the transmission clutches.
Torque Converter and Transmission Scavenge Section
Section (C)
Section (C) draws oil from the torque converter housing and from the transmission. Transmission scavenge oil from the transmission enters the pump through pump inlet (1). Also, torque converter scavenge oil from the torque converter enters the pump through pump inlet (3).
Within the pump, oil passes between gear (7) and gear (13). An auxiliary drive shaft from the engine drives gear (7). Gear (7) turns idler gear (13). The oil exits at pump outlet (2) and the oil returns to the bevel gear case. The oil is drawn through screens at the torque converter and the transmission.