BEARING 5D0458 - Caterpillar

Illustration 1 g03675634
View of the steering metering pump
Cover have been removed for clarity
Illustration 2 g00282859
Steering metering pump
NEUTRAL position
(1) Inner spool
(2) Drain outlet to tank
(3) Left turn port
(4) Outer sleeve
(5) Right turn port
(6) Inlet
(7) Passage
(8) Stator
(9) Rotor
(10) Passage
(11) Drive
(12) Pin
(13) Centering springs
(A) Control section
(B) Metering section The steering metering pump is made up of the following two sections:
Control section (A)
Metering section (B)The two sections are connected by hydraulics and by mechanics.Pump oil from the steering control valve goes through inlet (6) into control section (A). When the steering wheel is turned, control section (A) sends oil to metering section (B). Metering section (B) produces a specific amount of oil flow. Metered oil from metering section (B) is then directed by control section (A) to either left turn port (3) or right turn port (5). This oil becomes pilot oil for the steering control valve. As the steering wheel is turned faster, there is an increase in the flow of pilot oil. The steering cylinders will move farther with increased speed.Oil Flow
Control section (A) of the steering metering pump is a closed center type. When the steering wheel is in the NO STEER position, there is no alignment between the holes in sleeve (4) and the passages in spool (1). However, a small amount of pump oil from inlet (6) is allowed to flow through the center position of the steering metering pump. This small amount of oil flow (thermal purge) keeps the steering metering pump full. A full steering metering pump will give a response time that is quick to steering demands. The thermal purge also helps keep the pilot oil lines to the steering control valve and the steering metering pump warmed during cold-weather operations.Right Turn
Illustration 3 g00287150
Steering metering pump
Right turn
(1) Inner spool
(4) Outer sleeve
(5) Right turn port
(6) Inlet
(7) Passage
(8) Stator
(9) Rotor
(10) Passage
(11) Drive
(12) Pin
(13) Centering springs
(A) Control section
(B) Metering section
Illustration 4 g00282755
Spool and sleeve
(1) Inner spool
(4) Outer sleeve
(14) Holes for pin (12)
(15) Small holes for oil flow
(16) Grooves for oil flow
(17) Slots for centering springs When the steering wheel is turned clockwise, spool (1), pin (12) and drive (11) start to turn. Sleeve (4) will not turn because spool (1) will turn inside sleeve (4). Small holes (15) in sleeve (4) will be in line with grooves (16) in spool (1). The thermal purge is blocked when spool (1) and sleeve (4) rotate. Pump oil from inlet (6) goes through small holes (15) in sleeve (4) into grooves (16) in spool (1). The oil in grooves (16) goes out through other small holes (15) in sleeve (4) and into passage (10). Oil flows through passage (10) into metering section (B).