Locking Hubs - Automatic Free-Wheeling: Diagnosis Mazda MPV I

Testing Terminal Voltage

Remove center differential lock switch from instrument panel. (Scheme 5) Turn ignition on. Using voltmeter, backprobe between Green/Blue wire terminal and ground. With center differential lock switch off, battery voltage should be present. With center differential lock switch on, voltage should not be present. If voltage is not as specified, check switch continuity.

Testing Continuity

Disconnect center differential lock switch connector. Using ohmmeter, check continuity between terminals. With center differential lock switch off, continuity should not be present. With center differential lock switch on, continuity should be present. If continuity is not as specified, replace switch.

Scheme 5

Remove steering column covers. Turn ignition on. Using voltmeter, backprobe voltage between Light Green/White wire terminal of 4WD/2WD shift switch connector and ground. (Scheme 6) With 4WD/2WD shift switch released, battery voltage should be present. With 4WD/2WD shift switch activated (held to left), voltage should not be present. If voltage is not as specified, check switch continuity.

Disconnect 4WD/2WD shift switch connector. Using ohmmeter, check continuity between terminals "A" and "C" on switch side of connector. (Scheme 6) With 4WD/2WD shift switch released, continuity should not be present. With 4WD/2WD shift switch activated (held to left), continuity should be present. If continuity is not as specified, replace switch assembly.

Scheme 6

Disassembly & Inspection

1. With control box assembly removed from vehicle and disconnected from actuator, remove electrical switch and washer from housing. see scheme 2, see scheme 3 and see scheme 4. Remove spring cap, spring, detent ball and washer from housing. Using a punch and hammer, remove roll pin from control rod and shift fork. see scheme 17-23. Remove control rod and shift fork.
2. Place dog clutch ring in shift fork. Measure clearance between ring and fork. see scheme 17-23. Maximum allowable clearance is.020" (.50 mm). Replace shift fork or dog clutch ring if clearance is not as specified. Remove control rod dust boot from housing. Pry oil seal from housing.

1. Remove AFW assembly. See AFW ASSEMBLY under REMOVAL & INSTALLATION. Remove vacuum actuator from assembly. Remove circlip from differential side of shaft. Using Puller (49-0710-520), remove free-wheeling hub from housing and shaft assembly. Remove spacer and bearing retaining ring from shaft. see scheme 2, see scheme 3 and see scheme 4.
2. Press shaft and bearing out differential side of housing. Remove adjustment shim. Using Oil Seal Remover (49-U027-004), remove oil seal from housing. Remove circlip from drive axle side of shaft. Remove needle bearing from shaft. Using Oil Seal Installer (49-W027-001), remove dust seal and bearing from housing. Using a dial indicator, measure shaft runout. see scheme 17-23. Maximum allowable runout is.0012" (.030 mm).