General Information

POWER FLOW
1-Differential and bevel gear. 2-Winch drive line. 3-Power takeoff winch drive. 4-Diesel engine. 5-Final drive. 6-Drive line. 7-Parking brake. 8-Transfer gears. 9-Planetary transmission. 10-Torque converter. 11-Flywheel housing.

POWER FLOW
1-Differential and bevel gear. 6-Drive line. 8-Transfer gears. 9-Planetary transmission. 10-Torque converter. 12-Front differential.

Power from the diesel engine is transmitted directly from the engine flywheel to the torque converter. The torque converter output shaft gear transmits power to the transmission input shaft and the winch drive line. Five hydraulically actuated clutches, one rotating and four stationary, and four planetary systems are combined in the range transmission to provide three forward and three reverse speeds which are manually selected.

The range transmission output shaft transmits power to the transfer drive. The transfer drive transmits power, through universal joints and drive shafts, to the front and rear differentials. The bevel pinion and bevel gear of each differential transmit power through the differential to the axles. The axles are splined to the planetary final drive sun gears. As the sun gears rotate, planet gears, mounted in the final drive carrier, are forced to walk around the stationary ring gear, imparting rotation to the final drive carrier and the wheel to which it is fastened.

Torque Converter And Transmission

The transmission consists of a torque converter and a 3-speed forward, 3-speed reverse planetary gear transmission. The five clutches in the planetary are hydraulically controlled. Each speed is manually selected.

The single stage torque converter is located at the input end of the transmission. The converter driving gear meshes with the internal ring gear of the engine flywheel. Output torque from the converter enters the planetary transmission through the transmission input shaft. Which sun gear receives the output is dependent upon the directional clutch engaged.

The clutches of the planetary group are divided into two sections and identified according to their function. The No. 1 and No. 2 clutches comprise the directional section. The No. 3, No. 4 and No. 5 clutches comprise the speed section. It is necessary for one clutch from each section to be engaged for each speed. The No. 5 clutch gear in the planetary group serves as the transmission output member and is splined to the transfer drive input shaft gear.

The transfer drive input gear drives the transfer drive output shafts which connect through universal joints to the drive shafts.

Torque Converter

Oil for the operation of the converter is supplied by the transmission oil pump. The converter inlet oil pressure is controlled by the inlet ratio valve. The valve is located in the pressure control valve group in the transmission hydraulic controls.

The outlet oil pressure is determined by an orifice located in the converter outlet oil passage.

The input driving gear, rotating housing, impeller, impeller hub and the oil pump drive gear rotate as a unit at engine speed.

Oil, from the transmission hydraulic controls, enters the torque converter through an inlet port in the stator carrier. Oil is directed to the carrier by a passage in the converter housing.

POWER FLOW THROUGH TORQUE CONVERTER
1-Stator carrier. 2-Inlet port. 3-Turbine. 4-Stator. 5-Output shaft. 6-Outlet port. 7-Rotating housing. 8-Oil pump drive gear. 9-Impeller.

The impeller acts as a pump. As the impeller rotates, it directs oil to the rotating turbine. The turbine is splined to the output shaft. The turbine directs the oil to the stator which redirects the oil to the impeller. The stator is bolted to the carrier which is bolted to the converter housing.

Oil leaves the converter through an outlet port in the carrier. The oil flows through an oil cooler and then to the transmission lubrication system.

The energy imparted by the impeller transmits torque to the turbine and the output shaft. Under normal operating conditions, the oil passes through the converter easily and quickly striking each blade a very slight angle. When a load is encountered, the speed of the turbine is reduced, and the oil strikes the turbine blades at a sharper angle. This multiplies the torque delivered to the output shaft of the torque converter.

The output shaft of the torque converter drives a transfer gear train which transfers the torque to the input shaft of the transmission.

Planetary Transmission

The planetary transmission consists of two sections and are identified according to their function.

The directional clutch section consists of the No. 1 and No. 2 clutches and the No. 1 and No. 2 planetary carriers. The No. 1 clutch is the reverse directional clutch. The No. 2 clutch is the forward directional clutch. The No. 1 clutch ring gear and the No. 1 carrier are splined together and rotate as a unit. The No. 1 and No. 2 carrier ring gear, No. 2 and No. 3 carrier, and No. 4 carrier are splined together and rotate as a unit. The No. 1 and No. 2 sun gears are integral and turn as a unit.

RANGE TRANSMISSION (Earlier Machines)

RANGE TRANSMISSION (Later Machines)
1-No. 5 clutch housing. 2-No. 5 clutch. 3-No. 4 carrier. 4-No. 4 clutch. 5-No. 4 clutch planet gear. 6-No. 3 clutch planet gear. 7-No. 3 clutch. 8-No. 2 clutch planet gear. 9-No. 2 clutch. 10-No. 2 sun gear. 11-No. 1 clutch. 12-No. 1 clutch planet gear. 13-No. 1 sun gear. 14-Input shaft. 15-Output shaft. 16-No. 5 clutch gear. 17-No. 1 carrier. 18-No. 4 sun gear. 19-No. 4 clutch ring gear. 20-No. 4 clutch housing. 21-No. 3 sun gear. 22-No. 3 clutch ring gear. 23-No. 2 and No. 3 clutch housing. 24-No. 2 carrier. 25-No. 2 clutch ring gear. 26-No. 1 clutch housing. 27-No. 1 and No. 2 carrier ring gear. 28-No. 1 clutch ring gear.

The speed clutch section consists of the No. 3 (3rd speed), No. 4 (2nd speed) and No. 5 (1st speed) clutches and No. 3 and No. 4 planetary carriers. The No. 5 clutch is a rotating clutch and is bolted to the No. 4 carrier. The No. 3 and No. 4 sun gears are integral and are splined to the No. 5 clutch gear which serves as the output member of the transmission.

First Speed Forward

POWER FLOW - FIRST SPEED FORWARD (No. 2 & No. 5 clutches engaged)

The No. 2 clutch ring gear is held stationary causing the No. 2, No. 3 and No. 4 carriers and No. 5 clutch to rotate. Since the No. 5 clutch is engaged, torque is transmitted to the No. 5 clutch gear and output shafts.

Second Speed Forward

POWER FLOW - SECOND SPEED FORWARD (No. 2 & No. 4 clutches engaged)

The No. 2 clutch ring gear is held stationary. This causes the No. 2, No. 3 and No. 4 carriers to rotate. The No. 4 clutch ring gear is held stationary by the engaged No. 4 clutch. The No. 4 planet gears walk around the inside of the No. 4 clutch ring gear driving the No. 4 sun gear which in turn drives the No. 5 clutch gear and output shaft.

Third Speed Forward

POWER FLOW - THIRD SPEED FORWARD (No. 2 & No. 3 clutches engaged)

The No. 2 clutch ring gear is held stationary by the No. 2 clutch. The No. 3 clutch ring gear is held stationary by the No. 3 clutch. The No. 2 sun gear drives the No. 2 planet gears which walk around the inside of the No. 2 clutch ring gear to rotate the No. 2 carrier. The No. 3 planet gears are driven around the inside of the stationary No. 3 clutch ring gear and drive the No. 3 sun gear, No. 5 clutch gear and output shaft.

First Speed Reverse

The No. 1 clutch ring gear and No. 1 carrier are held stationary by the No. 2 clutch. The No. 1 sun gear drives the No. 1 and No. 2 carrier ring gear through the No. 1 planet gears. This causes the No. 2, No. 3 and No. 4 carriers and No. 5 clutch to rotate in the opposite direction. Since the No. 5 clutch is engaged, torque is transmitted to the No. 5 clutch gear and output shaft.

POWER FLOW - FIRST SPEED REVERSE (No. 1 and No. 5 clutches engaged)

In second speed reverse, the No. 1 and No. 4 clutches are engaged. The power flow through the directional clutch section is the same as for first speed reverse. Power flow through the speed clutch section is the same as for second speed forward.

In third speed reverse, the No. 1 and No. 3 clutches are engaged. The power flow through the directional clutch section is the same as for first speed reverse. Power flow through the speed clutch section is the same as for third speed forward.

Transmission Lubrication System

LUBRICATION SYSTEM

A gear-type oil pump provides oil for controlling the range transmission, charging the torque converter and lubricating the transmission and torque converter. The pump is driven at engine speed by a gear which meshes with the oil pump drive gear bolted to the torque converter impeller.

The transmission oil sump is located in the bottom of the transfer gear case. Oil is drawn through a screen and flows through an external oil tube to the transmission oil pump. The screen separates foreign material from the pump inlet oil. From the pump, the oil flows through the filter and into the transmission hydraulic controls. Should the filter element become restricted or the oil extremely viscous, a bypass valve in the filter opens. This allows the oil to bypass the filter element.

Valves in the hydraulic controls direct oil flow to the transmission clutches and torque converter. Oil not required to fill the clutches is routed into the converter. From the converter, the oil flows through a water-to-oil cooler and then to the planetary transmission. A lubrication relief orifice, on the right side of the transfer gear case, determines and maintains proper lubricating oil pressure.

TRANSMISSION LUBRICATION - SCHEMATIC

Transmission Hydraulic Controls

TRANSMISSION HYDRAULIC CONTROLS - SCHEMATIC (NEUTRAL - Engine stopped)
1-Torque converter. 2-Load piston. 3-Modulating relief valve. 4-Converter inlet ratio valve spool. 5-Lubrication relief orifice. 6-Pressure control valve body. 7-Combination-differential, safety, flow control, check-valve. 8-Oil cooler. 9-Directional selector valve spool. 10-Oil filter. 11-Lubrication oil line to transmission. 12-Oil pump. 13-Speed selector valve spools. 14-Oil sump. 15-Selector valve body. A-Torque converter inlet pressure tap. B-Torque converter outlet pressure tap. C-Speed clutch pressure tap. D-Directional clutch pressure tap. E-Lubrication pressure tap. F-Pump pressure tap.

The basic components of the transmission hydraulic control oil system are: oil sump (14), oil screen, oil filter (10), oil pump (12), transmission hydraulic control valves (6) and (15), torque converter (1) and oil cooler (8). The only external lines are those to and from the transmission oil cooler (8), and the oil pump suction tube from the transmission oil sump (14), to the oil pump (12).

The pressure control valve (6), the selector valve (15), a manifold and a plate comprise the hydraulic control group and are mounted on the center clutch housing. The controls are completely enclosed by the transmission case. Three forward and three reverse speeds are provided by the planetary range transmission and the hydraulic controls. The valve spools in the selector valve direct oil to pressurize the proper clutches for the speed and direction selected. Pressures in the control system are regulated and maintained by the pressure control valve.

When the engine is not running the spring-loaded valves and the load piston are held against their respective stops by spring force.

When the engine is started and the selector is in NEUTRAL, oil from the pump enters the controls and is routed to the modulating relief valve (3). The oil flows around the small diameter of the valve spool and enters the slug cavity end of the spool behind the poppet valve. The cavity behind load piston (2) is open to drain by the position of the combination valve (7) (a valve which functions as a differential, safety, flow control and check valve). In this instance, system pressure is held to initial pressure of approximately 75 PSI (5,3 kg/cm²).

When a shift is made and a transmission clutch is open to fill, the system pressure drops and spring pressure moves the modulating relief valve (3) to the left, closing off the oil supply to the torque converter (1). As the clutches fill, the system pressure increases to overcome the spring force and reopens oil flow to the torque converter. Further increase in system pressure causes the load piston (2) to move to the left and increases the spring force against the modulating relief valve (3). This gradual increase of clutch pressure, time versus PSI, is called modulation. When the speed clutches are full, the pressure will rise in the cavity at the left end of the combination-(differential, safety, flow control and check) valve and move it against its spring force. The cross-drilled passage in the combination valve (7) has now been opened to the directional clutch circuit. At this point the metering orifices, in the left end of the combination valve, act as a flow control valve and allow only 6 U.S. GPM (22,7 lit/min) to be routed to the directional clutch circuit while the remaining oil goes to the torque converter. When the directional clutch is full, pressure will increase in the center of the combination valve (7). This increased pressure plus the spring force will move the combination valve enough to close the metering orifice to maintain 50 PSI (3,5 kg/cm²) lower pressure in the directional circuit. The final speed clutch pressure will be approximately 305 PSI (21,4 kg/cm²). The directional clutch will engage last and receive the load.

If the engine is started when the selector lever is in any position but NEUTRAL, pressure oil will flow to both ends of the combination valve (7). Since the pressure is equal on both ends of the combination valve, the spring force will keep the valve to the left. In this position, the oil flow to the directional clutches is blocked and the machine will not move. When the selector lever is moved to the NEUTRAL position, the oil at the right end of the combination valve is open to drain through the large cavity in the bottom of the pressure control valve. Oil pressure then overcomes the spring force, the spool moves to the right and the controls are ready for a clutch fill and modulation cycle as soon as the selector lever is moved to a directional position.

The torque converter inlet ratio valve spool (4) limits the maximum pressure to the torque converter (1) to approximately 115 PSI (8,1 kg/cm²).

Torque converter outlet oil pressure is maintained by restrictions in the outlet lines.

Transmission lubrication oil pressure is maintained by an orifice in the transfer gear case.

TRANSMISSION HYDRAULIC CONTROLS - SCHEMATIC (NEUTRAL - FIRST)
1-Torque converter. 2-Load piston. 3-Modulating relief valve. 4-Converter inlet ratio valve spool. 5-Lubrication relief orifice. 6-Pressure control valve body. 7-Combination-differential, safety, flow control, check-valve. 8-Oil cooler. 9-Directional selector valve spool. 10-Oil filter. 11-Lubrication oil line to transmission. 12-Oil pump. 13-Speed selector valve spools. 14-Oil sump. 15-Selector valve body. A-Torque converter inlet pressure tap. B-Torque converter outlet pressure tap. C-Speed clutch pressure tap. D-Directional clutch pressure tap. E-Lubrication pressure tap. F-Pump pressure tap.

TRANSMISSION HYDRAULIC CONTROLS - SCHEMATIC (FIRST - FORWARD)
1-Torque converter. 2-Load piston. 3-Modulating relief valve. 4-Converter inlet ratio valve spool. 5-Lubrication relief orifice. 6-Pressure control valve body. 7-Combination-differential, safety, flow control, check-valve. 8-Oil cooler. 9-Directional selector valve spool. 10-Oil filter. 11-Lubrication oil line to transmission. 12-Oil pump. 13-Speed selector valve spools. 14-Oil sump. 15-Selector valve body. A-Torque converter inlet pressure tap. B-Torque converter outlet pressure tap. C-Speed clutch pressure tap. D-Directional clutch pressure tap. E-Lubrication pressure tap. F-Pump pressure tap.

TRANSMISSION HYDRAULIC CONTROLS - SCHEMATIC (THIRD - REVERSE)
1-Torque converter. 2-Load piston. 3-Modulating relief valve. 4-Converter inlet ratio valve spool. 5-Lubrication relief orifice. 6-Pressure control valve body. 7-Combination-differential, safety, flow control, check-valve. 8-Oil cooler. 9-Directional selector valve spool. 10-Oil filter. 11-Lubrication oil line to transmission. 12-Oil pump. 13-Speed selector valve spools. 14-Oil sump. 15-Selector valve body. A-Torque converter inlet pressure tap. B-Torque converter outlet pressure tap. C-Speed clutch pressure tap. D-Directional clutch pressure tap. E-Lubrication pressure tap. F-Pump pressure tap.

Differential And Final Drive

Differential

DIFFERENTIAL
1-Side gear. 2-Pinions (four). 3-Bevel ring gear. 4-Spider. 5-Bevel pinion.

The differential equalizes the driving torque delivered to both wheels. When one wheel is turning slower than the other, as in a turn, the differential allows the inside wheel to stop or slow in relation to the outside wheel.

The transmission output shaft gear meshes with the transfer output shaft gear which transmits power through universal joints to the drive shafts. The drive shafts are splined to bevel pinion (5) in each differential. The bevel pinion drives the ring gear (3) which is bolted to the differential carrier. The carrier contains four pinions (2), mounted on a spider (4), and two side gears (1). The four pinions mesh at right angles with the two side gears. The side gears are splined to the inner ends of the axles.

When the machine is moving straight ahead with equal traction under each wheel, equal torque on each axle locks pinions (2) so they will not rotate on spider (4). This gives the same effect as both drive wheels locked on the same driving axle. When unequal loads are put on the drive wheels, as in a turn, unequal forces are placed on the opposite sides of the differential, causing the pinions to rotate. This rotation of the pinions slows or stops the inside wheel and speeds up the rotation of the outside wheel, thereby driving the machine with full power in a turn.

The differential carrier hubs are mounted on tapered roller bearings. The pinions rotate on hardened steel bearings. Both the pinions and side gears rotate against thrust washers which take the end thrust against the differential carrier.

The differential is splash lubricated. Milled flats on the spider allow passage of lubricant to the pinion bearings and thrust washers.

Final Drive

FINAL DRIVE AND WHEEL (Front Wheel Illustrated)
1-Brake disc. 2-Ring gear. 3-Planet gear. 4-Sun gear. 5-Axle shaft. 6-Axle housing. 7-Final drive hub. 8-Planet carrier.

The final drive consists of a planetary gear system. Ring gear (2) is mounted on final drive hub (7) which is splined to axle housing (6). The ring gear remains in a fixed position. Planet gears (3) are held by a planet carrier (8) which is bolted to the wheel. Sun gear (4) is splined to axle shaft (5) which is driven by the differential. As the sun gear rotates it causes the planet gears and carrier to walk around the sun gear in the same direction, but at a reduced speed. The planet carrier drives the wheel assembly.

Torque Proportioning Differential

TORQUE PROPORTIONING DIFFERENTIAL
1. Ring gear. 2. Carrier. 3. Axles (two). 4. Bevel pinion. 5. Pinion gears (twelve). 6. Side gears (two).

The torque proportioning differential divides torque to the wheels according to conditions at the wheels. When one wheel is turning slower than the other, as in a turn, the differential allows the inside wheel to stop or slow in relation to the outside wheel.

The transmission output shaft gear meshes with the transfer output shaft gear which transmits power through universal joints to the differentials.

The differential pinion (4) drives the differential ring gear (1) which is bolted to the differential carrier (2). The carrier contains twelve helical cut pinions (5) and two side gears (6). The pinions are arranged in four groups of three pinions, one group in each quadrant. Two of the pinion gears (5) in each group mesh with the side gears (6) while the remaining pinion in each group serves as an idler gear. The side gears (6) are splined to the inner ends of the axles (3).

When the machine is moving in a straight line and when both wheels encounter the same tractive conditions, the torque from the bevel gear (1), drives the carrier (2), and the four sets of pinion gears (5). The pinion gears (5) cause both side gears (6) to rotate in the same direction at bevel gear speed.

When traction decreases at one wheel the axle shaft torque required to turn that wheel decreases. In order for a wheel to spin, one side gear (6) must rotate faster than the other side gear. When this occurs the pinions must have relative rotation and walk around the other side gear.

The torque proportioning differential restricts this rotation. A frictional resistance must be overcome to allow the pinion to rotate. The frictional resistance results from the contact between the helically cut pinions (5) and side gears (6) and the preload spring force on the side gears. To allow one side gear to speed up, an input torque to the carrier is required to overcome the frictional resistance. This causes the pinions to rotate about the slower moving side gear. A reaction torque is created at the slower moving side gear and in turn, torque is transmitted to the wheel with the best traction.

The differential carrier hubs are mounted on tapered roller bearings. The pinion gears rotate on shafts which are fixed in the carrier housing.