Type 1065 Rear Axles with Locking Differential

General Information
A differential locking mechanism controlled by a centrifugal governor has been introduced on certain rear axle variants on models from 1990 on (1991 USA). Rear axles of this type are designated 1065.

The device operates automatically when one of the drive wheels is spinning and the speed of the car is less than 40 km/hr (25 MPH). The tractive effort is then transferred to the wheel with the best grip at that instant.

The mechanism disengages automatically and the [1][2]differential resumes normal operation at approx. 40 km/hr (25 MPH).

Internal Components





[1][2]Differential and lock mechanism consist of the following main components (refer to the illustration):

Operation Of Differential Lock
The differential lock does not engage when the car is being driven at a steady speed and both drive (axle) shafts are rotating at the same speed. Under these conditions, the [1][2]differential functions exactly as a conventional type.

Engagement
The following sequence of events occurs if one drive wheel begins to spin and the speed of the car is also less than approx. 40 km/hr (25 MPH).
The [1][2]differential (wheels) commences to rotate relative to the differential housing.





A cam wheel (11) attached to the left-hand [1][2]differential gear (9) drives a centrifugal governor (3) consisting of a pair of flyweights.





As the governor rotates, the weights move outwards under the action of centrifugal force and are blocked by the latch (4), stopping the rotation of the governor and, as a result, the cam wheel.





The relative displacement between the cam wheel and [1][2]differential gear, which occurs as the wheel stops, causes the cam curves on the two components to compress the clutch assembly (6), exerting a braking action on the drive (axle) shaft.





The reaction force displaces the block (10) towards the opposite side of the [1][2]differential, causing the right-hand differential gear (8) to compress the clutch assembly (5) on that side, thereby locking the complete unit.





At speeds above 40 km/hr (25 MPH), the weighted latch (4) takes up a position in which the governor (3) is completely free to rotate and the locking mechanism cannot be activated.

Disengagement
The locked [1][2]differential is disengaged automatically once the speed of the car exceeds 40 km/hr (25 MPH), at which point the latch releases the governor weights. The differential gear on the left-hand side reverts to its normal position once an exchange of torque takes place between the wheels or in response to the slightest steering correction.

IMPORTANT: Both wheels must be jacked up when carrying out wheel balancing. Support vehicle properly.

NOTE:
- Under extreme conditions, the clutch assemblies will slip to protect the [1][2]differential from overload.
- Only Volvo hypoid oil or grade GL5 hypoid oil may be used in this [1][2]differential.