The bevel pinion, bevel gears and hydraulic pump are turning whenever the tractor PTO shaft is turning. The bevel pinion transmits torque from the PTO shaft to the bevel gears, clutch shaft and winch gear train. Proper adjustment of bevel pinion/bevel hear back-lash and tooth contact pattern is essential for quiet operation and long component life.
The bevel pinion and hydraulic pump share common carrier housing. The carrier is mounted in the front face of the winch case and will be located in the upper bore for standard PTO winches and in the lower case bore of low PTO winches.
An improvement was made to the design of the bevel pinion carrier with regards to the dual tapered bearing support of the pinion. For more than 25 years, Carco used a Timken "set-right" matched bearing set with cup and cone spacers. The .005-.010 in. (.13-.25 mm) typical end play that was always present in the "set-right" bearing set could at times make setting bevel gear back-lash difficult. The bearing cups were arranged with the thick ends (small ID) against a matched shoulder spacer held in position by a retaining ring in the carrier bore. The bearing cones were separated by a spacer ground to a pre-determined thickness. When the bearing lock-nut was tightened to 150 lb-ft (203.4 N·m) torque, the bearing cones were firmly clamped against the spacer. The end-play mentioned above resulted from the retaining ring-to-groove clearance and the shoulder spacer-to-retaining ring clearance.
The new bevel pinion carrier contains a shoulder machined in the bore that locates and separates the bearing cups. The bearing cones no longer use a cone spacer between them. The bearings are adjusted by carefully tightening the bearing lock-nut to produce a 10 lb-in (1.3 N·m) rolling torque. The bevel pinion has no end-play so the bevel gear back-lash and contact adjustments are easier and more accurate. The bearing cone close to the pinion head supports the axial thrust of the bevel gear set and the bearing cone toward the tractor can resist thrust that may be induced by the tractor PTO shaft.
The original design carrier housing is no longer available and is fully serviced by the new "rolling torque" bevel pinion carrier. In the following text, the original Timken "Set Right" bearing arrangement will be identified with the note (original). The new bevel pinion carrier that uses separate pairs of cups and cones is the current design.
Bevel Pinion Carrier Removal
Drain oil from winch and remove the winch from the tractor as described in "Winch Removal and Installation" section of this manual. Leave the winch mounting adapter plates attached to the tractor where applicable.
Standard PTO shown
Remove the 1/2 in. capscrews which secure the bevel gear inspection plate to the top of the winch case. Remove the inspection plate. Remove the pump suction tube and pressure hoses from the pump. Remove the capscrews (3) securing the carrier assembly to the winch case. Using two of the capscrews as "jackscrews", remove the carrier assembly. Retain the shim set (13, 14, 15) for reassembly.
Bevel Pinion Removal
Bend the tang of the lockwasher (4) away from the locknut (2) and remove the locknut (2) and lockwasher (4).
Support the carrier assembly in a suitable press. Place support blocks toward the outer diameter of the carrier. From the locknut end, press out the bevel pinion (16).
Remove the bearing cone set spacer from the bevel pinion. (Original) Position the bevel pinion assembly in a suitable press with support blocks under the pump drive pinion (10) as close to the bevel pinion gear as possible. Press the bevel pinion (16) free of the bearing cone and pump drive pinion.
Support the carrier in a vice and remove oil seal (8), oil seal spacer (9) and O-ring (5).
Remove the oil seal retaining ring (7) and outer bearing cone. Remove the bearing cups, bearing cup retaining ring and the set spacer from the carrier.
Remove the retaining ring (19) and plug (20) from the end of the bevel pinion. Remove the O-ring (18) from the groove in the gear.
Thoroughly clean and inspect all parts at this time.
All components of the bearing assembly are a matched set with the bearing adjustment controlled by the inner and outer set spacers. If the bearing cone or cup is worn or damaged, the entire bearing assembly (1) must be replaced. (Original)
Bevel Pinion Assembly
Lubricate and install O-ring (18) into the groove in the bore of the bevel pinion (16). Install plug (20) with chamfered edge toward the O-ring. Secure the plug in the pinion with the retaining ring (19).
NOTE: On bevel pinions equipped with a threaded plug, apply Loc-tite 242 or equivalent to socket head plug and tighten securely.
Clean and dry bore of pump drive pinion (10) and mating surface on bevel pinion (16) with Loc-tite cleaner 7070 or equivalent.
Apply Loc-tite 609 or equivalent to pump drive pinion bore and mating bevel pinion surface. Press pump drive pinion onto bevel pinion and seat securely against bevel pinion shoulder. Allow Loc-tite to harden.
Press one bearing cone of the bearing assembly (1) on to the bevel pinion and seat securely against the pump drive pinion. Install bearing cone set spacer on to the bevel pinion.
Install the bearing cup retaining ring into the groove in the carrier bore.
Place the carrier assembly onto bench with the pump side facing up. Install one bearing cup of bearing set (1) and seat against the retaining ring.
Turn the carrier over so that the pump side faces down. Install the bearing cup spacer with the shoulder inside of the retaining ring. Install the remaining bearing cup and seat firmly against the bearing cup spacer and retaining ring.
Place the carrier over the bevel pinion so that the pump side bearing cup seats on the bearing cone.
Press the remaining bearing cone securely onto the bevel pinion, seating into the bearing cup.
Lubricate and install O-ring (5) onto the bevel pinion against the bearing cone. Install seal spacer (9) over the bevel pinion with internal tapered edge toward the bearing cone and O-ring.
Install the oil seal retaining ring (7) into the carrier bore groove. Apply non-hardening sealant to the outside surface of the oil seal (8) and install the oil seal firmly against the retaining ring (7).
Install the bearing lockwasher (4) and locknut (2) onto the bevel pinion. Tighten the locknut to 150 lb-ft (203 N·m) torque and bend tang of lockwasher (4) into slot of locknut.
Clean preservative oil off of bearing cups and cones. Press bearing cone (4) onto bevel pinion and fully seat against pump drive pinion as shown. Install bearing cups (3) into bevel pinion carrier (1) with thick edge; small inside diameter against the shoulder. Install the bevel pinion sub-assembly into the carrier. Install the remaining bearing cone onto the bevel pinion. Install O-ring (7) onto pinion against the outer bearing cone. Install retaining ring (5) into bevel pinion carrier bore. Apply Permatex Aviation Form-A-Gasket liquid sealant to the outside surface of seal (6) and press into carrier bore with the open spring side of the seal facing the bearings. Apply light grease to the inside and outside surface of seal spacer (8) and install inside diameter chamfer for O-ring (7) toward the bearings.
Install bearing lockwasher (9) and bearing locknut (10) onto pinion. Clamp pinion gear in workshop vise equipped with aluminum or bronze jaw protectors. Rotate bevel pinion carrier to align bearing cone rollers as you slowly tighten the bearing lock nut. When a slight drag is noticed as the bevel pinion carrier is rotated, remove carrier from vise and wrap nylon cord around the bevel pinion and slowly pull the cord at a steady rate and measure the resistance with a "fish scale". At the pump drive pinion diameter, the rolling torque should be approximately 3 pounds (1.4 kg).
If a dial type torque wrench is available, install the PTO adapter shaft onto the bevel pinion or use a Timken 11N socket that fits the torque wrench/meter and can turn the bevel pinion. The rolling torque should be 8-10 lb-in (1.1 N·m). Bend bearing lockwasher tang up to lock nut in correct position.
Bevel Pinion Carrier Installation
Apply gear tooth marking compound to bevel pinion and install carrier assembly into winch case using the original shim set. Replace shim gasket. Tighten capscrews to 75 lb-ft (102 N·m) torque.
Rotate bevel pinion in same direction as PTO shaft rotation and check bevel pinion/gear tooth contact pattern. See typical contact patterns below.
Remove carrier assembly to add or remove shims to obtain the correct tooth contact pattern illustrated below.
Refer to Clutch Shaft Service for bevel gear backlash adjustment procedure.
Apply approximately .20 in (5 mm) continuous bead of Dow RTV 732 or equivalent silastic sealant to carrier pilot.
Clean dowel pin (11) with Loctite Cleaner 7070 and apply Loctite 242 or 243 to dowel pin and install in winch case.
Install suction and pressure hoses to pump. Install completed bevel pinion carrier assembly into winch case. Clean capscrews (16) with Loctite Cleaner 7070. Apply Loctite 242 or 243 to capscrews and evenly tighten to 80 lb-ft (108 N·m) torque.
Refill winch to proper level with recommended lubricant.
Hydraulic Pump Service
The hydraulic pump supplies oil to the control valve to recharge the accumulator, apply clutches, release the brake, and lubricate critical components. Maintaining adequate oil flow is critical to reliable winch operation.
Pump flow should be tested with an accurate, commercially available flow meter. If a flow meter is not available, a serviceable flow meter may be fabricated from a gate valve, tee and gauge as listed below.
- * Gate valve-1/2 NPT Port minimum, 1000 PSI (6,895 kPa) rating, minimum.
- * 1/2 NPT schedule 80 pipe tee with a -8JIC hose adapter on one run.
- * Accurate 0-600 PSI (0-4,137 kPa) gauge.
- * 1/2 NPT schedule 80 pipe tee with a -8JIC hose adapter on one run.
Attach 1/2 NPT run end of tee to gate valve with -8JIC adapter on opposite run. Install gauge to branch of tee.
1. Operate tractor and winch long enough to bring oil up to operating temperature 100-120 F (38-49 C). Stop engine.
2. Remove access cover on right hand side of winch and locate pump port on control valve labeled "P". Remove -8JIC pump line from the tee in the pump port of the control valve.
3. Attach pump line to the gauge side of the gate valve or flow meter. Direct the open end of the gate valve/flow meter back into the winch case.
4. With gate valve/flow meter fully open, operate engine at 650-700 RPM and measure oil flow by directing oil into a container for 15 seconds.
5. Gradually close gate valve/flow meter until you have applied 350 PSI (2413 kPa) load to the pump. Again record the flow for 15 seconds.
The minimum acceptable pump flow is 2 gpm (US) (7.6 lpm) at 650-700 RPM PTO speed and 350 PSI (2413 kPa). Two quarts (2 liters) per 15 seconds equals 2 gpm.
If pump flow is below minimum:
1. Check/verify PTO speed and accuracy of tachometer.
2. Check suction strainer for restriction.
3. Check suction hose for cracks or poor connection.
4. Pump is worn and required replacement.
Hydraulic Pump Removal
Remove the 1/2 in. capscrews which secure the bevel gear inspection cover to the top of the winch case. Remove the inspection plate. Remove the pump suction tube and pressure hose from the pump. In most applications, the pump may be removed from the bevel pinion carrier through the top of the winch case. If this is not practical in your application, then remove the bevel pinion carrier from the winch case as described in the "Bevel Pinion Carrier Service" section of this manual.
Remove the four capscrews and lockwashers (5, 6, 7) securing the pump to the bevel pinion carrier.
Remove the pump assembly and wear plate (1) from the bevel pinion carrier.
Thoroughly clean and inspect all pump components at this time. If there is any sign of damage or wear which may reduce pump performance, the entire pump assembly must be replaced.
Lubricate entire pump assembly with recommended oil.
Coat the capscrew threads with Loc-tite 242 or equivalent and evenly tighten to 100-110 lb-in by 25 lb-in (11.3-12.4 N·m by 2.8 N·m) increments in a cross pattern.
When properly installed, there will be a slight gap, .005-.040 in. (.13-1.02 mm) between the mounting ears of the pump housing and the bevel pinion carrier. This condition insures that the pump housing is clamped and sealing against the wear plate.
Apply non-hardening thread sealant to the pipe threads and install the suction (3, 4) and pressure (2) hose adapters as follows:
- A. For counter-clockwise (ccw) bevel pinion rotation, the most common, install the pressure adapter into "A" port.
- B. For clockwise (cw) bevel pinion rotation, install the pressure adapter into "B" port.
NOTE: Determine direction of bevel pinion rotation when viewed from rear of winch looking forward toward the tractor.
Install suction tube assembly (standard PTO) or suction hose and clamp (low PTO) securely to the pump suction port.
Install the pressure hose securely to the pump pressure port and make certain the hose is routed away from the bevel gears and clutch housing to avoid chaffing and failure.