The winch (Fig. 2) is designed for self-recovery, as well as for pulling out vehicles and trailers on difficult sections.
It consists of a worm gearbox, a drum with a cable attached to it, and a cable guide.
The gearbox mechanism consists of a globoid pair with a gear ratio of 31:1.
The worm wheel 20 is riveted to the hub, which can be connected to the drum shaft 7 by the movable coupling 12.
An automatic band brake 1 (Fig. 3) is installed on the gearbox worm, preventing spontaneous rotation of the winch drum and unwinding of the cable when the vehicle clutch is disengaged and when the safety pin is sheared.
Adjust the brake with the drive operating in reverse gear and the movable drum coupling disengaged.
If the brake heats up above the temperature that the hand can withstand (about 60 °C) within 1–3 minutes, unscrew the nut 3 and lock nut 4 of the band fastening by two or three turns.
Adjusting the winch gearbox
Adjust the gearbox bearings when axial play appears in them, as well as when installing a new worm pair.
Adjust the bearings only if tightening the bearing cover bolts has not eliminated the axial play.
The bearings must be adjusted with preload.
The torque required to turn the gearbox worm in bearings 29, 31 and 32 (see Fig. 2) should be 1.0–2.5 N·m (0.1–0.25 kgf·m).
If the shaft rotates too freely or has axial play, remove some of the shims 28 and 33 of equal thickness from under the front and rear bearing covers.
If rotating the shaft requires a torque of more than 2.5 N·m (0.25 kgf·m), add shims of equal thickness under the covers.
When checking the worm shaft torque, the cover mounting bolts must be fully tightened.
The number of shims under the rear and front covers after adjustment should be approximately the same, which facilitates subsequent adjustment of the worm pair engagement.
Adjust the tapered bearings of the worm wheel shaft by changing the number of shims 16 and 24 under the bearing covers.
Check the preload of the worm wheel shaft bearings in engagement with the worm.
The torque required to turn the worm wheel shaft in the bearings should be 3–6 N·m (0.3–0.6 kgf·m).
After adjusting the bearings, check the correctness of the worm pair engagement with paint using the tooth contact pattern.
In a properly adjusted pair, the contact pattern of the working surface of the unloaded wheel tooth should be located in its middle and be at least 5 mm wide and 2/3 of the tooth height.
The position of the contact pattern along the tooth height is changed by correspondingly moving the worm 30 axially using shims.
To shift the contact pattern towards the tooth root, remove some of the shims 28 from under the cover 27 on the flange side; to shift the contact pattern towards the tooth tip, add shims.
Accordingly, change the number of shims 33 under the cover 37 on the brake side so that the total thickness of the shims on both sides is maintained.
The displacement of the contact pattern along the tooth width is achieved by axially moving the worm wheel in the same direction as the pattern has shifted.
The globoid worm pair can only work well with correct engagement adjustment.
Incorrect adjustment is the cause of strong heating of the pair and rapid wear of the worm wheel teeth.
Winch drive
Power from the transfer case through the auxiliary power take-off is transmitted to the winch gearbox by three driveshafts.
On the front driveshaft, a safety pin 2 (Fig. 3) is installed to protect the winch parts from overload; it shears when the load exceeds the permissible value.
All universal joints are identical in design and are identical to the joints of the GAZ-53A vehicle.
The intermediate driveshaft is mounted on two supports.
To compensate for inaccuracies during assembly, sliding yokes 7 of the front and rear shafts are installed on the splined ends of the intermediate driveshaft.
The lubricant in the splined joint is retained by sealing rings 8.
To reduce the uneven rotation of the winch gearbox worm, the drive driveshafts are installed so that the axes of the bearing holes in the sliding yokes of the front 4 (see Fig. 5) and rear 6 shafts lie in the same plane.
Cable guide
The winch is equipped with a cable guide (Fig. 4) that ensures proper cable layering on the drum when the angles of deviation from the vehicle axis do not exceed 15°.
The cable is secured to the drum with a clamp and is only released backwards.
The guide roller holder body 22 lays the cable, performing a reciprocating movement along the lead screw 6 and along two guide rollers 7.
The screw with left and right threads, mounted on two bearings, is rotated by a chain drive from the drum shaft through the drive 16 and driven 10 sprockets.
The chain tension is adjusted by shims 2 and 14; the chain sag should be 3–10 mm.
The axial force from the lead screw 6 is transmitted to the guide roller holder body through the lead screw slide block 20.
The slide block is installed in the guide roller holder body and secured by cover 21.
The guide rollers 19 are mounted on polyamide bushings 18 and rotate on pins 17, which are secured by lock plate 5.
Rules for using the winch
Before operating the winch, make sure that the winch drum engagement and disengagement drive is working correctly, and that the cable winding and attachment are correct and secure.
With a properly adjusted drive, the length of rod 10 (see Fig. 3) along the axes of the holes of the adjusting yokes should be 228–232 mm.
If the winch drum is difficult to engage in cold weather, it is necessary to warm up the winch gearbox at idle for 3–5 minutes.
Do not use the winch cable for towing a vehicle or trailer, nor when the angle of deviation from the vehicle axis exceeds 15°.
To engage the winch:
- - set the transfer case and gearbox levers to the neutral position;
- - using a 30 mm wrench, set the movable coupling lever to the upper (engaged) position for forced cable release.
For manual cable unwinding, the movable coupling lever must be in the lower (disengaged) position;
- - release the lock and move the auxiliary power take-off lever forward to the stop;
- - engaging first or second gear, release the cable to the required length; take up cable slack by hand.
Before starting to pull, the drum must have at least three to four turns of cable;
- - engage reverse gear to pull the load;
- - for self-recovery of the vehicle, engage the transfer case low gear and the gearbox reverse gear.
Increase the engine crankshaft speed smoothly.
A sharp increase in engine speed does not increase the pulling force on the cable, but may cause the safety pin to shear.
After the pin shears, immediately disengage the clutch and move the gear shift lever to neutral; otherwise, the shaft may jam in the flange.
Replace the sheared pin with a new one.
Do not use bolts or other parts instead of the safety pin.
In operation, it is difficult to determine the force on the cable; therefore, before using the winch, roughly determine the feasibility of using a pulley block based on specific conditions.
The use of the winch with a pulley block is shown in Fig. 7. When using a pulley block without a hook, use the towing cable attached to the vehicle.
If the pulley block is used to increase the pulling force during self-recovery (position I), it is secured with the towing cable to the object chosen as a support, and the hook of the winch cable is attached to the hook of the towing device.
If the pulley block is used to change the direction of pull when pulling out another vehicle (position II), it is secured using the towing cable to the object serving as a support, and the hook of the winch cable is attached to the towing hook of the vehicle being pulled out.
If the pulley block is used to increase the pulling force when pulling out another vehicle (position III), it is secured to the towing hook or to the towing cable thrown over the towing hooks of the vehicle being pulled out, and the hook of the winch cable is attached to a fixed object using a second towing cable.
It is allowed to fasten the winch cable directly to a fixed object, with the hook hooked onto the previously tensioned cable.
To avoid overheating of the winch gearbox, do not pull the load using the full cable length more than three times in a row with maximum or near-maximum load.
Maintenance
During winch maintenance, after 10–15 pulls or once a year during the "maintenance", replace the oil in its gearbox (Fig. 8).
To do this, drain the oil from the gearbox and fill through the filler plug with 7.5 litres of engine oil.
Lubricate the winch drum shaft bearing with Litol-24 grease (Fig. 2).
Clean the winch from dirt and lubricate the lead screw and cable guide chain, check the winch mounting and the condition of the driveshaft drive to it.
Winch lubrication points:
- 1 – winch gearbox, once every two years, 7.5 litres of hypoid oil;
- 2 – towing device bushings, two lubrication points, after 4000 km of mileage, Litol-24 grease;
- 3 – working surfaces of the winch cable guide lead screw, lubricate with graphite grease after each use of the winch. Roller bushings and cavities of the guide roller holder body of the winch cable guide, lubricate with graphite grease during disassembly;
- 4 – winch cable guide chain drive, lubricate once a year with USsA graphite grease;
- 5 – winch drum shaft plain bearing, lubricate once a year during seasonal maintenance.
