SkyTrak 8042 Service Manual - Manual (Page 276)

5.3 Model 8042, 10042, 10054 Legacy Rev. 10/03
Axles, Drive Shafts, Wheels and Tires
5.2 GENERAL INFORMATION
IMPORTANT: To help ensure optimum performance, the
drive shaft assemblies are specially balanced as a unit at
the factory. When servicing any flange yoke, slip yoke or
drive shaft tube, order a complete assembly if
components are bent or damaged. Refer to the
appropriate parts manual for ordering information.
Before performing any inspection, maintenance or
service operation, thoroughly clean the unit. The axles
and drive shafts should be checked and repaired only by
experienced service technicians who are aware of all
safety instructions and particular component features.
Use suitable products to thoroughly clean all
disassembled mechanical parts to help prevent personal
injury to the worker and prevent damage to the parts.
Carefully inspect the integrity of all moving parts
(bearings, yokes, tubes, gears, shafts, etc.) and fasteners
(nuts, bolts, washers, etc.) as they are subject to major
stress and wear. Always replace elastic locknuts and any
damaged, worn, cracked, seized or otherwise improper
parts that could affect the safe and proper functioning of
the vehicle, axles and drive shafts.
5.3 AXLE ASSEMBLIES
5.3.1 Axle Assembly Description
The front (parking brake equipped) and rear (no parking
brake) ZF axles are designed for heavy-duty, off-road
industrial use. Each axle consists of a beam-type axle
case, housing the differential center section, inboard wet-
disc brakes, a pair of trumpet-like shaft housings and
stub-axle/wheel-hub units at each end. O-rings and oil
seals retain fluid within the axle. The axles have a semi-
floating mounting configuration. Each axle center is
secured to the vehicle frame with a pivot pin, and at one
side with a cylinder, anchor and pins.
The frame sway cylinder is mounted on the right side of
the front axle, and the stabilizer cylinder is mounted on
the left side of the rear axle. Steering cylinders and ball
joints are mounted inboard on each axle.
5.3.2 Axle Assembly Operation
Power from the engine is transmitted to the transmission
by way of a driveshaft. The transmission distributes
power through the output drive shafts to the front and rear
axle differentials. The axles work through gearing to turn
the wheel and tire assemblies and to ultimately cause the
vehicle to move.
The front differential is equipped with limited-slip, self-
locking gears supported by bearings. The design of the
differential permits adjustment to the bevel gear set.
Internal axle service and adjustment procedures are not
the scope of this publication and are thoroughly covered
in the appropriate ZF axle manual. The beveled ring gear
is adjusted by means of ring nuts located opposite each
other. The position of the pinion, supported by two
bearings, is adjusted through the addition or subtraction
of adjusting shims.
The wheel hubs containing the planetary reduction gears
are supported by two tapered roller bearings. The oil-bath
(wet) disc type brakes are located in the center housing,
and are operated by an annular piston. The parking brake
is located in the center section of the front axle. The brake
is spring-applied, hydraulically released (SAHR). The
parking brake uses the same discs as the service brakes.
A double-rod hydraulic steering cylinder is mounted on
the differential support. Directional steering input is
transmitted to the axles by means of articulated track
rods that allow toe-in adjustments.
The axles are attached to the chassis by a pivot pin. The
pin allows the axle to pivot freely, each limited by the
hydraulic cylinder attached to one of the bridge casting
bearing lugs.
Note: Detailed axle service instructions (covering the
axle, differential, brakes and wheel-end safety, repair,
disassembly, reassembly, adjustment and
troubleshooting information) are provided in the ZF Axle
Repair Manuals. (Refer to Section 5.3.8, “ZF Axle Repair
Manuals.”)
The Model 8042 uses a wheel type with nominal
dimensions of 9" x 24". An optional wheel type with a
nominal dimension of 13" x 25" is available.
Models 10042 and 10054 uses wheels with nominal
dimensions of 13" x 25".
WARNING:
DO NOT service the vehicle
without following all safety precautions as
outlined in Section 1, “Safety Practices,” of this
manual. Failure to follow the safety practices
may result in death or serious injury.