TM 5-2420-230-24-1
Maintenance & Service Manual
R & HR32000 3 & 6 Speed LD
When either directional clutch is selected the opposite clutch is relieved of pressure and vents back through the direction selector
spool. The same procedure is used in the speed selector.
The direction or speed clutch assembly consists of a drum with internal splines and a bore to receive a hydraulically actuated piston.
The piston is "oil tight" by the use of sealing rings, A steel disc with external splines is inserted into the drum and rests against the
piston, Next, a friction disc with splines at the inner diameter is inserted, Discs are alternated until the required total is achieved. A
heavy back-up plate is then inserted and secured with a snap ring. A Hub with O.D. splines is inserted into the splines of discs with
teeth on the inner diameter The discs and hub are free to increase in speed or rotate in the opposite direction as long as no pressure
is present in that specific clutch.
To engage the clutch, as previously stated, the control valve is placed in the desired position, This allows oil under pressure to flow
from the control valve, through a tube, to a chosen clutch shaft. This shaft has a drilled passageway for oil under pressure to enter the
shaft. Oil pressure sealing rings are located on the clutch shaft, These rings direct oil under pressure to a desired clutch, Pressure of
the oil forces the piston and discs against the heavy back-up plate, The discs, with teeth on the outer diameter, clamping against discs
with teeth on the inner diameter, enables the hub and clutch shaft to be locked together and allows them to drive as a unit.
There are bleed balls in the clutch piston which allow quick escape for oil when the pressure to the piston is released.
R-32000
HR-32000
MHR-32000
FIG. A
F-28