Locking Hubs - Automatic Ford Bronco II I

DESCRIPTION

The hub locks on 4WD Ranger and Bronco II vehicles lock either automatically or manually. When actuated, the hub locking assembly locks hub, wheel and tire assembly to the front driving axle shaft. When released, the front driving axleshaft is disengaged from hub locking assembly. This action releases the hub, tire and wheel assembly to rotate freely on the spindle. Two tapered opposed roller bearings allow hub and wheel and tire assembly to rotate on spindle. A seal is installed behind inner bearing to prevent wheel bearing lubricant from contaminating brake caliper and rotor surfaces.

2WD

Shift transfer case in "2H" position by pushing the "Low Range" and/or 4x4 push buttons. Ensure that both indicator lights are off. To disengage the automatic locking hubs, move vehicle in opposite direction (forward or reverse) and drive a minimum of 10 feet in a straight line. Always disengage hub locks before driving vehicle on dry, hard pavement.

Shifting Between 2H & 4H

The transfer case can be shifted between 2H and 4H with the vehicle stopped or at normal road speed by depressing the 4x4 button. The Amber indicator light will illuminate when vehicle is in 4WD.

Shifting Between High/Low Ranges

Stop vehicle and shift transmission to neutral. On manual transmission models, disengage the clutch before depressing "Low Range" button. "Low Range" light should illuminate. DO NOT attempt to shift from or to "Low Range" with vehicle in motion. When an attempt is made to shift in motion, "Low Range" light will begin to flash. It will continue to flash until shift position is reselected or previous procedure is followed.

Shift transfer case to "2H" position and manually turn hub lock selector knob counter clockwise to "Free" position.

4WD

Lock both hubs by turning selector knob clockwise to "Lock" position. If hub teeth DO NOT engage with knob in this position, a slight movement of wheel in either direction will complete lock. If vehicle is stopped, place transmission in Neutral and select transfer case shift position. If vehicle is moving, transfer case may be shifted between "2H" and "4H" only, providing that hub locks are in "Lock" position. Shifting to or from "4L" position requires that vehicle be fully stopped and transmission be in Neutral.

Note. Both hubs must be set in same function to avoid excess front differential wear on non-traction-lok front axles or steering pull on traction-lok front axles.

Note. Clashing of gears and resulting transfer case damage will occur if an attempt to shift to or from "4L" is made while vehicle is in motion. Damage may also occur if an attempt to shift from "2H" to "4H" with hub locks in the "Free" position is made, while vehicle is in motion. If it is necessary to shift to or from "4L", bring vehicle to a full stop before doing so.

Scheme 1

1. Raise vehicle and install safety stands. Remove wheel and tire assembly. Remove manual locking hub assembly from spindle. Remove snap ring from end of spindle shaft. Remove axle shaft spacer, needle thrust bearing and bearing spacer. (Scheme 1)
2. Remove outer wheel bearing lock nut from spindle using a 4-pronged spindle nut spanner wrench. Make sure tabs on tool engage slots in lock nut. Remove lock nut washer from spindle.
3. Loosen inner wheel bearing lock nut using 4-pronged spindle nut spanner wrench. Make sure that tabs on tool engage slots in lock nut and that slot in tool is over pin on lock nut. Tighten inner lock nut to 35 ft. lbs. (47 N.m) to seat bearings.
4. Spin rotor and back off inner lock nut 1/4 turn. Install lock washer on spindle. It may be necessary to turn inner lock nut slightly so pin on lock nut aligns with closest hole in lock washer (a couple tries may be necessary).
5. Install outer wheel bearing lock nut using a 4-pronged spindle nut spanner wrench. Tighten lock nut to 150 ft. lbs. (203 N.m). Install bearing thrust spacer, needle thrust bearing and axle shaft spacer. Clip snap ring onto end of spindle.
6. Install manual hub assembly over spindle. Install retainer washers. Install wheel and tire assembly. Install and tighten lug nuts. Check end play of wheel and tire assembly on spindle. End play should be.001-.003" (.02-.08 mm).

Scheme 2

1. Raise vehicle and install safety stands. Remove wheel and tire assembly. Remove retainer washers from lug nut studs and remove automatic locking hub assembly from spindle.
2. Remove snap ring from end of spindle shaft. Remove axle shaft spacer, needle thrust bearing and bearing spacer. Being careful not to damage plastic moving cam, pull cam assembly off wheel bearing adjusting nut and remove thrust washer and needle thrust bearing from adjusting nut. (Scheme 2) NOTE: To prevent damage to spindle threads, look into spindle keyway under adjusting nut hole and remove any portion of locking key that has been separated from cam assembly before removing adjusting nut. If this condition exists, DO NOT re-use. Discard entire cam assembly and replace with Service Kit (1A053).
3. Loosen wheel bearing adjusting nut from spindle using a 2-3/8" hex socket. While rotating hub and rotor assembly, tighten wheel bearing adjusting nut to 35 ft. lbs. (47 N.m) to seat bearings, then back off nut 1/4 turn.
4. Retighten adjusting nut to 16 INCH lbs. (1.8 N.m) using a torque wrench. Align closest hole in wheel bearing adjusting nut with center of spindle keyway slot. Advance nut to next hole if required. CAUTION: Extreme care must be taken when aligning spindle nut adjustment hole with center of spindle keyway slot to prevent damage to cam assembly locking key.
5. Install lock nut needle bearing and thrust washer in order of removal and push or press cam assembly onto lock nut by lining up key in fixed cam with spindle keyway. Install bearing thrust washer, needle thrust bearing and axle shaft spacer.
6. Clip snap ring onto end of spindle. Install automatic locking hub assembly over spindle by lining up 3 legs on hub assembly with 3 pockets in cam assembly. Install retainer washers. Install wheel and tire assembly. Install and tighten lug nuts. Final end play of wheel on spindle should be.001-.003" (.02-.08 mm).

Removal

1. Raise vehicle and install safety stands. Remove wheel lug nuts and remove wheel and tire assembly. Remove retainer washers from lug nut studs and remove manual locking hub assembly.
2. To remove internal hub lock assembly from outer body assembly, remove outer lock ring seated in hub body groove. (Scheme 3) Internal assembly, spring and clutch gear will now slide out of hub body. DO NOT remove screw from plastic dial. Rebuild hub assembly in reverse order of disassembly.

Scheme 3

Installation

Install manual locking hub assembly over spindle and place retainer washers on lug nut studs. Install wheel and tire assembly. Install lug nuts and tighten.

Removal & Installation

To remove and install automatic locking hubs, use AUTOMATIC LOCKING HUBS - FRONT WHEEL BEARING ADJUSTMENT procedure in this article.

All models are a chain driven, part time 4WD unit. Some models are equipped with an Electronic Shift Transfer Case which is activated by push button controls located in an overhead console on Bronco II and Ranger or lower right hand corner on instrument panel on Bronco. This system allows the vehicle to be shifted from 2WD high to 4WD high at any vehicle speed.

Electronic Shift Operation

The system consist of a push button control, electronic control motor with integral shift position sensor and a speed sensor.

The transfer case is equipped with a magnetic clutch located inside the case next to the 2WD/4WD shift collar. The clutch is used to spin up the front drive system from zero to vehicle speed in less than a second. This spin-up allows the 2WD to 4WD shift to be made at any speed.

When the transfer case rear and front output shafts reach the same rotating speed, the spring loaded shift collar mechanically engages the mainshaft hub to the chain drive sprocket. The magnetic clutch is then deactivated. Shifts between 4WD high and 4WD low only occur with clutch interlock or transmission safety switches closed. Vehicle speed must also be 3 MPH or under.

When the operator selects the 4WD or 2WD drive mode, the actual shifting is carried out by electric motor mounted on the transfer case.

Electronic Control Module

This module controls operation of transfer case using inputs from push button controls, speed sensor and shift position sensor. On Bronco and "F" Series, module is located in right kick panel. On Bronco II and Ranger, module is located to left of right side speaker in instrument panel. Instrument panel pad must be removed to replace module. Module is equipped with a self-test capacity.

When either of the 2 switches in the overhead console are depressed, the electronic control module will analyze information from the transfer cases shift position sensor to verify its current position. The module also receives data from the speed sensor and clutch interlock switch, or Neutral safety switch depending on application.

If all design conditions are met, the electronic control module will signal the electronic shift motor to shift gear positions. After shift takes place, the module will read the input from the shift position sensor to determine if transfer case is in desired position. The electronic control module also will illuminate push buttons on overhead console indicating shift is completed.

Speed Sensor

Mounted on the rear of the transfer case, the speed sensor tells the electronic control module the correct speed to shift the transfer case. Speed sensor picks up rotating speed of output shaft from 2 notches cut in opposite sides of outer ring of clutch housing assembly. (Scheme 4)

Shift Position Sensor

The shift position sensor tells the electronic control module the shift position of the transfer case. It is an integral part of the transfer case. (Scheme 4)

Electric Shift Motor

Mounted externally on the rear of the transfer case, this motor is responsible for shifting between 4WD and 2WD. The motor drives a rotary helical cam which moves the 2WD/4WD shift fork and 4H-4L reduction shift fork to selected drive position.

Scheme 4

Circuit Protection

The battery feed circuit, through a circuit breaker, provides memory capability for the electronic control module. Ignition "RUN", and "ACC" circuits, through a fuse, supply power for switches and electric shift motor. The side marker light circuit supplies power for illumination of overhead console.

Control Module Self-Test

1. To perform electronic control module self-test, remove the 5-wire connector and the 8-wire connector from the module. Turn ignition switch to "RUN" position.
2. Activate the self-test switch and note result. A flashing indicator light indicates control module is okay. A steady indicator light indicates control module is inoperative and must be replaced.

8-Wire Pigtail Connector Test

1. With ignition off, unplug the 8-wire connector from the module. Connect voltmeter between terminal No. 8 and ground. Battery voltage should be present at all times. (Scheme 5)
2. Connect voltmeter between terminal No. 7 and ground. Turn ignition to "RUN" position. Battery voltage should be present. CAUTION: Turn off ignition before proceeding with ohmmeter test. NEVER connect an ohmmeter to powered circuit.
3. Connect ohmmeter between terminal No. 6 and ground. There should be less than 10 ohms present. Connect ohmmeter between terminals Nos. 4 and 5 of connector. Resistance should be less than 10 ohms.
4. Connect ohmmeter between terminal 3 and ground. There should be zero ohms. Resistance between terminal 2 and ground should be zero ohms.

Scheme 5

5-Wire Connector Test

1. Connect ohmmeter between terminal Nos. 1 and 2. Depress "4x4" switch in overhead console. Resistance should be less than 50 ohms while switch is depressed. (Scheme 7)
2. Connect ohmmeter between terminal Nos. 1 and 3. Depress "LOW RANGE" switch in overhead console. Resistance should be less than 50 ohms with switch depressed.
3. Connect jumper wire between terminal No. 4 and ground. Turn ignition switch to "RUN" position. Light in overhead console low range bar should illuminate. Turn ignition off and remove jumper wire.
4. Connect jumper wire between No. 5 and ground. Turn ignition to "RUN" position. The "4x4" bar should illuminate on overhead console.

8-Wire Harness Connector Test

1. Turn ignition off. Connect ohmmeter between terminal No. 1 and ground. On manual transmission, depress clutch pedal and observe ohmmeter. There should be less than 50 ohms.
2. On automatic transmission, shift transmission into Neutral and observe ohmmeter. There should be less than 50 ohms.
3. Measure resistance between terminal Nos. 2 and 3. There should be 200-350 ohms. This checks speed sensor continuity. Connect ohmmeter between terminal No. 8 and, in turn, terminals No. 4, 5, 6 and 7. Resistance should be as specified. (Scheme 6)

Scheme 6

Scheme 7

Main Feed Connector

Main feed connector is located near middle of instrument panel. (Scheme 9)

10-Pin Connector

For functions of 10-pin connector (Scheme 8)

Scheme 8

Scheme 9

2-Pin Connector

For functions of 2-pin connector (Scheme 10)

Scheme 10

Electronic Transfer Case Feed

For functions of transfer case feed (Scheme 11)

Scheme 11

Removal (Bronco & "F" Series)

Raise vehicle. Remove front drive shaft from transfer case yoke. Remove front drive shaft from transfer case yoke. Wire drive shaft out of way. Remove yoke. Using Seal Remover (T74P-77248-A) and Slide Hammer (T50T-100-A), remove oil seal. Remove oil slinger from yoke.

Apply oil seal with Dexron II ATF. Using Oil Seal installer (T83T-7065-B) and Handle (T80T-4000-W), install new oil seal. To complete installation, reverse removal procedure.