RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN 7 (2001)
Fluid - Differential: Description and Operation
DESCRIPTION
The 286 Rear Beam-design Iron (RBI) axle housings consist of an iron center casting (differential housing) with axle shaft tubes extending from either
side. The tubes are pressed in to form a one-piece axle housing.
The integral type housing, hypoid gear design has the centerline of the pinion set below the centerline of the ring gear.
The axles are equipped with full-floating axle shafts, meaning that loads are supported by the axle housing tubes. The full-float axle shafts are retained
by bolts attached to the hub. The hub rides on two bearings at the outboard end of the axle tube. The axle shafts can be removed without disturbing or
removing the wheel bearings. The wheel bearings are opposed tapered roller bearings and are contained in the hub assembly,
The removable, stamped steel cover provides a means for inspection and service without removing the complete axle from the vehicle. A small,
stamped metal axle gear ratio identification tag is attached to the housing cover via one of the cover bolts. This tag also identifies the number of ring
and pinion teeth.
The rear wheel anti-lock (RWAL) brake speed sensor is attached to the top, forward exterior of the differential housing. A seal is located between the
sensor and the wire harness connector. The seal must be in place when the wire connector is connected to the sensor. The RWAL brake exciter ring is
press-fitted onto the differential case against the ring gear flange.
The differential case for the standard differential is a one-piece design. The differential pinion mate shaft is retained with a roll pin. Differential
bearing preload and ring gear backlash are adjusted by the use of shims located between the differential bearing cones and case. Pinion bearing
preload is set and maintained by the use of solid shims.
Axles equipped with a Trac-Lok differential are optional for the 286 RBI axle. A Trac-lok differential contains two clutch packs, four pinion gears,
and a one-piece pinion mate cross shaft to provide increased torque to the non-slipping wheel in addition to the standard differential components. A
Trac-Lok differential for the 286 RBI axle has a two-piece differential case.
OPERATION
STANDARD DIFFERENTIAL
The axle receives power from the transmission/ transfer case through the rear propeller shaft. The rear propeller shaft is connected to the pinion gear
which rotates the differential through the gear mesh with the ring gear bolted to the differential case. The engine power is transmitted to the axle shafts
through the pinion mate and side gears. The side gears are splined to the axle shafts.
During straight-ahead driving, the differential pinion gears do not rotate on the pinion mate shaft. This occurs because input torque applied to the
gears is divided and distributed equally between the two side gears. As a result, the pinion gears revolve with the pinion mate shaft but do not rotate
around it (Fig. 1).