GEAR-SUN-YM 4507550 - Caterpillar

The brake assembly is located on the right hand side of the winch in the lower winch case bore on a low PTO and upper winch case bore on a Standard PTO winch. Standard PTO shown.The winch gear train is connected to the brake assembly by the brake hub, attached to the end of the clutch shaft. The brake hub is splined to eight friction discs (11). The friction discs are alternately stacked between steel discs (12), which are splined to the brake housing (15), which is anchored to the winch case.Two large disc type springs (13) exert a tremendous force against the brake piston (4) and retainer (3) to hold the brake disc pack compressed, locking the winch gear train to the winch case.Whenever the operator applies a clutch or shifts to "Brake-Off", hydraulic pressure is directed to the brake chamber to overcome the spring force and relieve the compression of the discs. When released, the brake hub and gear train can turn as the brake friction discs slip freely between the brake steel discs.If the operator returns the controls to the neutral "Brake-On" position, the hydraulic pressure will be exhausted from the brake chamber and the brake springs will quickly reapply to lock the winch gear train to the brake housing through the brake discs.In most applications, the brake assembly may be removed for service with the winch mounted on the tractorBrake Assembly Removal
Drain oil from the winch into a suitable container and recycle or dispose of used oil in an environmentally responsible manner.Remove the six 1/2 in. capscrews securing the brake assembly to the winch case. Do not remove the two 3/8 in. capscrews (2) which secure the bearing carrier to the brake housing at this time.The brake may be removed from the winch case by carefully using a pry bar between the brake housing and winch case. Be careful not to damage the shim set.Remove the brake assembly from the winch case. The brake assembly weighs approximately 80 lbs (36 kg). Retain the shim set for reassembly. Disassembly
Place the brake assembly onto a work bench with the disc end down. Remove the two 3/8 in. capscrews (2) securing the bearing carrier (14) to the brake housing (15) and remove the carrier. Remove the retaining ring from inside of the carrier and remove the rotary seal and O-ring assembly; replace as required. Inspect the bearing cup (1) in the bearing carrier; replace as required.Remove and discard the three O-rings (5) from the oil port grooves in the brake housing. Remove the two brake springs (13). Note the position of the springs for reassembly.Place the brake assembly on the work bench with the disc end facing up.Remove retaining ring (9) and pressure plate (17).Remove the friction discs and steel discs (11 & 12).Inspect the friction discs for wear and flatness. Original friction disc thickness is .138-.144 in. (3.5-3.8 mm). The oil groove depth of a new disc is .015 in. (.38 mm) minimum. Replace friction discs