BUSHING-LEVER 0676084 - Caterpillar

Illustration 1 g00926718
The transmission main relief valve (1) controls the maximum pressure of the clutches that are engaged. The transmission relief valve controls the flow of oil that enters the modulating valves and the transmission relief valve directs the remaining oil to the torque converter. The controlled flow provides a constant fill time for the clutches through the entire engine speed range.The transmission relief valve (1) is located on the control manifold with the modulating valves.
Illustration 2 g00908806
Pump oil (14) flows into the port from the pump (6). The pump oil (14) flows into orifice (13) and the pump oil unseats ball (10). When ball (10) unseats, spring (9) compresses against slug (8). The pump oil flows past ball (10) and into chamber (11). The pressure in chamber (11) moves spool (12) to the right against spring (2). When spool (12) moves to the right, pump oil in the port from the pump (6) flows past the spool and into the port to the torque converter (5) as torque converter oil (15). Oil in chamber (3) is vented to the port to tank (4) as tank oil (16) .The pressure in the port from the pump will vary slightly with the demand from the clutches. When the pressure changes, spool (12) will move in order to maintain the required engagement pressure to the clutches. Spool (12) will direct the unneeded flow to the port to the torque converter.When the pressure in port (6) decreases, spring (2) will move spool (12) to the left. When the spool moves to the left, the flow of oil into the port to the torque converter will be blocked. As the pressure drops further, spring (9) will push ball (10) to the right. When ball (10) moves to the right, the flow of oil from the port from pump (6) into chamber (11) will be blocked. Oil in chamber (11) will drain back into the port from pump (6) through orifice (7) when ball (10) is moved to the right.