Worm Gear Winch Preventive Maintenance

Recommended Preventive Maintenance Intervals:

A regular program of preventive maintenance for your Braden winch will minimize the need for emergency servicing and promote long product life and trouble-free service.

The service intervals suggested in this manual will optimize component service life. The intervals may be gradually increased or decreased with experience of a particular lubricant and evaluation of your application.

!WARNING!
Never attempt to service a winch with the prime mover running as accidental engagement may result in property damage, severe personal injury or death.

Make certain all load is removed from winch cable and cable drum before servicing winch. A loaded winch cable may rapidly unspool resulting in property damage, severe personal injury or death.

Perform all daily inspections.
Check worm gear housing oil level and fill to the proper level with recommended oil. The proper oil level for most worm gear winches is near the centerline of the worm shaft. Locate the proper oil level plug for your application. For boom tip winches, turret winches and winches mounted upside down, fill to level plug or halfway up on worm and be certain that the safety brake has sufficient oil when it is located in the highest position. Overfilling the winch may result in oil leaks. Underfilling the winch may result in rapid wear of the worm gear set.
Lubricate the grease fittings on the bearing legs and cable drum. On some winches, you may have to unspool the wire rope to gain access to the grease fittings in the cable drum. Use a high-quality, moly-type grease with a rating of NLGI-2 or better.
Inspect and retighten as required, all winch mounting fasteners. Inspect and repair as required, all winch mounting brackets and welds.

Worm Shaft End-Play Adjustment:

When repairing the winch, the worm shaft end-play should be carefully checked. Excessive worm shaft end-play will cause oil leaks around the worm shaft seals and greater heating and wear of the worm gear set. Too little worm shaft end-play will not allow for thermal expansion of the worm which may cause damage to the worm shaft bearings and bearing containers.

Worm shaft end-play is adjusted by adding or removing gaskets between the worm gear housing and the bearing container. Refer to the "Oil Capacity and Worm Shaft End-Play" chart for specifications.

Before adjusting worm shaft end-play, the worm gear set should be inspected for excessive wear or shock-load damage. Shock loaded gears may be distorted to the point where the self-locking gear design no longer provides adequate braking action and the worm shaft safety brake repeatedly requires adjustment or slips under heavy loads. Severely worn gears may not have adequate strength to withstand shock loads and heavy pulls.

If the gears have been distorted, the tips of the gear teeth may appear to be leaning in one direction in relation to the gear tooth root. Do not confuse this with the normal worm gear tooth helix angle. Replace all worn or damaged parts as required.

Check/adjust worm shaft end-play as follows:

Remove hydraulic motor and motor adapter from winch if equipped. Remove safety brake housing if equipped. Remove drive sprocket or sheave from worm shaft if equipped. Re-tighten bearing container capscrews to recommended torque values from torque chart.
Attach dial indicator base to worm gear housing and place probe of dial indicator squarely against the end of the worm shaft.
Grasp the cable drum and rotate firmly in one direction and hold constant tension. Zero the dial indicator. Now firmly rotate the drum in the other direction and hold constant tension. Record the worm shaft end-play and compare with specifications.
If too tight, remove the bearing container capscrew and bearing container and add one shim/gasket at a time between the bearing container and the worm gear housing. Then recheck end-play. If too loose, remove one gasket at a time to achieve the recommended end-play.
Complete end-play adjustment procedure by re-tightening the bearing container capscrews to the recommended torque, refilling winch with recommended worm gear oil and adjusting the worm gear safety brake.

Safety Brake Service & Adjustment: Oil-Cooled-Type Brake Service and Adjustment:

The Braden oil cooled safety brake is installed on the model OS4 and all winches with a capacity rating of 12,000 lbs. (53.4 kN) or higher. When properly serviced and adjusted, this brake will provide reliable service for many years.

Description

The oil cooled safety brake consists of a brake rotor assembly located between two friction discs. An adjustable leaf spring assembly pushes against a pressure plate to hold the discs against the rotor.

The safety brake is located on the worm shaft of the winch and is contained in the brake housing. The spring tension may be adjusted to compensate for component wear until wear limits are reached. The adjusting nut is readily accessible without removing any parts from the winch.

!WARNING!
Slow unwinding of the cable drum under load may be a warning that the safety brake needs adjustment or repair. Do not continue to use a winch with a worn brake. Loss of load control may result in property damage, severe personal injury or death.

ROTOR ASSEMBLY

The rotor assembly (see illustration) is actually a one-way clutch which allows the worm shaft to turn freely in the haul-in direction but immediately locks up when winch operation is complete and the load tries to back drive the winch. When the winch is powered in the haul-in direction the rotor driver turns free of the rotor disc due to the tapered design of the roller pocket. When input power is removed and the load tries to drive the worm shaft in the opposite direction, the rollers are forced to the narrow end of their pockets and lock the rotor driver to the rotor disc. The disc is locked in place by the friction discs and the load is held.

The friction discs are held against the rotor disc at all times, but only experience relative movement when the winch is being powered out to lower a load.

SERVICING

Drain oil from worm gear housing as described earlier. Remove the capscrews which secure the brake housing to the worm housing. Remove the brake housing, leaf spring assembly, pressure plate and outer brake disc. Before removing the rotor assembly, mark it to insure that it will be reinstalled in the same direction of rotation. Remove the rotor assembly and inner friction disc.

Inspect the friction discs for excessive heat, distortion, material transfer and excessive wear. If the oil grooves in the sintered metal facing (where applicable) are worn smooth, the friction disc should be replaced. The friction discs may be cleaned with safety solvent and emery cloth to remove light heat glazing.

Inspect the rotor assembly for damaged rollers, roller springs/plungers or rotor discs. Replace rotor as an assembly if any part is damaged or unit fails to turn smoothly in the free direction and lock firmly in the opposite direction.

The leaf spring should be replaced as an assembly, if it has lost its tension, has cracked spring leaves or damaged adjuster threads.

After thorough cleaning and inspection, reassemble brake using the following procedure: Install a new rotor drive key into the worm shaft. Pre-lubricate brake discs with worm gear oil and place the inner friction disc over the worm shaft against the bearing container. Install the rotor assembly onto the worm shaft in the same direction as it was removed. Check that the rotor assembly has been properly installed by holding the rotor housing (disc area) stationary while rotating the worm shaft in the haul-in direction. If the shaft turns free of the rotor housing in haul-in, it is correctly installed. Install the outer friction disc, pressure plate and leaf spring assembly (refer to the drawings following). Install the brake housing using new gaskets and seals as required. Evenly tighten capscrews to recommended torque. Refill the winch to the proper level with recommended oil.

Winches smaller than MS20

Note that the leaf spring is positioned between the cast ribs in the safety brake housing.

MS20 winches and larger

In the drawing on the left, the leaf spring is shown properly positioned in the safety brake housing. Note that it IS NOT located between the cast lugs. The drawing on the right shows the leaf spring properly positioned in relationship to the pressure plate. The dotted lines represent the position of the cast lugs in the housing when the pressure plate is in place.

!WARNING!
Periodic inspection and adjustment of the safety brake is required due to normal wear. Failure to maintain the safety brake adjustment may prevent the winch from holding the maximum rated load securely. Loss of control may result in property damage, severe personal injury or death.

If the brake rotor is not installed for the proper direction of winch rotation, the brake will not be effective which may result in the loss of load control and cause property damage, severe personal injury or death.

ADJUSTMENT

There are three (3) methods for adjusting the Braden oil-cooled safety brake. Method 1 is the preferred method and is used at the factory as the standard adjustment procedure. Method 2 and 3 may be used when the proper tools are not available. Method 3 may be used for periodic field adjustment and as a final test for method 2.

Method 1

Disengage the drum clutch. Adjustment is made by turning the brake adjustment nut in the center of the safety brake housing counter-clockwise to tighten the brake or clockwise to loosen it. Some winch models are equipped with an adjusting screw lock-plate on the end of the brake housing which is locked into place with two small capscrews. These capscrews must be removed before the brake can be adjusted.

A torque wrench can be equipped with a special adapter or socket which will engage the key (similar to the one shown in the illustration), in the input end of the worm shaft. Proper torque can then be applied to the worm shaft to adjust the brake (refer to torque chart below). NOTE: Only the input end of the worm shaft must be turned with the torque wrench, NOT the brake adjusting nut. In the event that the special adapter is not available, the use of a pipe wrench and weights has been successful in some cases. To use the pope wrench method, place the wrench on the input shaft in a horizontal position. Hang a weight from the handle, one foot (305 mm) from the center of the shaft. Select the weight that matches the torque from the chart. If the weight can be hung two feet (610 mm) from the shaft, use one half the weight shown. It is a good idea to tighten the brake adjustment first, then apply the weight and loosen the adjustment until the weighted wrench begins to move. Retighten until the wrench stops.

Method 2 - For Mechanically Driven Winches Only
Disengage the drum clutch. Engage the power take-off to drive the winch in the reel-out direction. With the truck in neutral operate the engine at 1,500 r.p.m. and disengage the truck clutch. If the safety brake is properly adjusted, the winch drive sprocket will stop turning immediately. The brake will overcome the inertia of the gear train from the truck transmission through the safety brake.

Method 3 - May Be Used For Hydraulically-driven Winches
Thoroughly inspect winch drum clutch, wire rope and rigging. Repair or replace as required. Refer to the "Maximum Load and Input RPM" chart in the specifications section of this manual to determine the safe working limits of your particular winch.

Securely attach winch cable to test load which should be the maximum weight anticipated in your application. Raise load a short distance then stop. Winch should hold the load. With engine at recommended PTO operating speed, lower load and stop before load contacts ground. Winch should stop and hold the load securely.

If, when using one of these methods for checking the adjustment, the brake does not hold, turn the adjusting nut ½ turn in the counter-clockwise direction and repeat the testing sequence until the brake holds properly.

!CAUTION!
Do not adjust the safety brake to higher torque values than shown in the chart below as this will cause excessive heating, glazing and abnormal wear of the friction discs under normal pay-out operations. Using a winch with worn brake components may result in a loss of load control which could cause property damage, severe personal injury or death.

TORQUE CHART
(Torque required to turn winch input shaft for brake adjustment)

*Model UT15 and W150A are equipped with a spring applied, multi-disc oil brake which is adjusted by turning the adjusting screw clockwise to tighten and counter-clockwise to loosen, all others counter-clockwise to tighten.

Dry Band-Type Automatic Safety Brake:
The Braden dry band-type, automatic safety brake is used on several models of winches with capacity ratings of less than 12,000 pounds (53.4 kN). The brake utilizes an external, contracting, self-energizing dry brake band acting on the worm shaft brake drum. One feature of this brake is that it may be adjusted for increased load requirements or it may be fully released for special applications.

It should be noted that the majority of a worm gear winch's braking effort is achieved by the inability to back-drive the worm gear set. The band-type safety brake provides additional resistance to rotation of the worm shaft and absorbs the inertia of the P.T.O. gear train if so equipped.

The brake band and cover must be installed over the brake drum so that the worm shaft can turn freely to haul-in a load and must overcome the resistance of the brake band to pay-out a load.

Adjustment:
Loosen the jam nut on the brake bank stud next to the tension spring. Turn the adjusting nut clockwise, in ½ turn increments, to tighten the brake and counter-clockwise to loosen the brake. When adjustment is completed, tighten the jam nut.

Assembly Change Instructions:

This procedure provides instructions for changing Braden worm gear winches equipped with the oil-cooled safety brake, from a left-hand assembly to a right-hand assembly or from a right-hand assembly to a left-hand assembly. No additional parts required.

Place the winch on a sturdy work surface so that the input shaft is away from you and the oil-cooled safety brake is toward you. The winch shown in drawing 1 below is a front-drive, left-hand assembly with under-winding cable spooling.
Remove the drain plug and drain the oil into a suitable container as described previously.
Remove the capscrews which secure the safety brake housing to the worm housing. Remove the safety brake housing containing the leaf spring assembly and pressure plate.
Remove the outer friction disc. Mark the outer surface of the safety brake rotor assembly to assist in re-assembly. Remove the rotor assembly and inner friction disc. Remove the bearing container from the worm housing. Note the number and total thickness of the gaskets removed. Gaskets may be reused if not damaged.
Using a pair of locking type pliers and a hammer, remove the sprocket key from the input end of the shaft. Remove any burrs or sharp edges on the shaft end and around the keyway to prevent damage to the shaft seal.
Remove the input end bearing container. Note the number and total thickness of the gaskets removed because the same amount (thickness) must be replaced to keep the original worm shaft end play adjustment. Remove the worm shaft, worm and bearing assembly from the worm housing by rotating the shaft until the worm thread is disengaged from the worm gear teeth.
Insert the worm shaft into the opposite side of the worm housing and rotate the shaft to screw the worm thread into engagement with the worm gear. Place the input end bearing container and gaskets over the input end of the worm shaft. Lift the worm shaft up into full engagement with the worm and push the bearing container into the worm gear housing. Install the input end bearing container capscrews and tighten finger tight at this time. Place the brake end bearing container and gaskets over the brake end of the worm shaft and support the worm shaft as you push the bearing container into the worm gear housing.
Install the safety brake housing (without rotor and discs) and capscrews. Evenly tighten the brake housing and bearing container capscrews to recommended torque. Attach dial indicator base to worm gear housing to place probe of dial indicator squarely against the end of the worm shaft. Grasp the cable drum and rotate firmly in one direction and hold constant tension. Zero the dial indicator. Now firmly rotate the drum in the other direction and hold constant tension. Record the worm shaft end play and compare with specifications. If too tight, remove the bearing container capscrews and bearing container and add one shim at a time between the bearing container and the worm gear housing. Then recheck end play. If too loose, remove one gasket at a time to achieve the recommended end play. Complete end play adjustment procedure by reassembling the brake as described in "Oil Cooled Safety Brake Service". Retighten the bearing container capscrews to the recommended torque and refill winch with recommended worm gear oil. Adjust the worm gear safety brake as described earlier.

IF YOUR WINCH IS EQUIPPED WITH A CABLE DRUM BAND BRAKE, THE FOLLOWING ADDITIONAL INSTRUCTIONS ARE APPLICABLE.
Remove the drum clutch and band brake control shafts from the base of the winch. This is accomplished by loosening the set screws in the thrust collars and levers, then pulling the control shafts from the winch. Do not disconnect any parts from the drum brake band unless they prevent its removal for reversing. Remove all levers and collars from the shafts and brake band anchor bracket from the base angle.
Remove the brake band from the cable drum, turn around from the original position and replace on the cable drum. Install the control shafts, collars, levers and set screws. Secure the brake band anchor bracket to the base angle as shown.
Attach the brake band link to the brake band and the anchor bracket. Since the control shafts are reversed because of the brake band arrangement, it is necessary to change the control linkage for the winch clutch as well.
This illustration shows a front-drive, right-hand assembly with overwind cable spooling.

PREVENTIVE MAINTENANCE