Published 4-20-2015, Control # 502-01 8-1
RT540E SERVICE MANUAL UNDERCARRIAGE
SECTION 8
UNDERCARRIAGE
SECTION CONTENTS
Axles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
Wheels and Tires . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
Steering Systems . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . 8-10
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
Rear Steering System. . . . . . . . . . . . . . . . . . . . . 8-12
Hydraulic Pumps. . . . . . . . . . . . . . . . . . . . . . . . . 8-13
Front Steering Control Valve. . . . . . . . . . . . . . . . 8-13
Integrated Outrigger/Rear Steer Manifold. . . . . . 8-13
Steer Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
Rear Axle Oscillation Lockout System. . . . . . . . 8-15
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15
Axle Oscillation Lockout Cylinders . . . . . . . . . . . 8-15
Brake System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . 8-16
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17
Service Brakes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Corrosion Protection . . . . . . . . . . . . . . . . . . . . . . 8-22
Parking Brake Actuator. . . . . . . . . . . . . . . . . . . . . 8-24
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25
Park Brake Valve . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Outriggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Outrigger Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Outrigger Beam . . . . . . . . . . . . . . . . . . . . . . . . . . 8-31
Extension Cylinder. . . . . . . . . . . . . . . . . . . . . . . . 8-35
Jack Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-36
Outrigger Control Valves . . . . . . . . . . . . . . . . . . . 8-38
AXLES
Description
To provide maximum maneuverability, both the front and rear
axles are steerable. The rear axle (Figure 8-3) is mounted on
a pivoting cradle (fifth wheel) which allows the axle to
oscillate while traversing uneven terrain. The front axle
(Figure 8-4) is bolted directly to the frame. All four wheels
utilize a hydraulic braking system. The axles are equipped
with disc type brakes. A disc-type parking brake is mounted
on the front axle input shaft, at the transmission.
Each axle incorporates a single reduction carrier with hypoid
gearing mounted in the axle center. The final reduction is of
planetary design spur gearing built into the wheel hubs.
The design of these axles permits the hypoid gearing of the
differential carrier and the axle shafts to carry only a nominal
torsional load while at the same time providing the highest
practical numerical gear reduction at the wheels.
The hypoid pinion and differential assembly of the first
reduction are supported by tapered roller bearings. The
pinion bearing preload is adjusted and maintained by a
hardened precision spacer between the inner and outer
bearing. The differential tapered bearing preload is adjusted
and maintained by the positioning of the threaded adjusting
rings in the carrier leg and cap bores.
In the planetary wheel ends, the spur teeth of the sun gear
mesh with teeth of the planet spur gears. The planet spur
gears rotate on planet pins which are mounted in a spider.
The planet spur gear teeth in turn mesh with teeth of the
floating ring gear.
Power is transmitted by the hypoid gear set in the differential
carrier to the axle shafts and the sun gear of the final
reduction, through the revolving planet gears, and into the
planetary spider which drives the wheel hub.
As an option, the front axle and rear axle may be provided
with a differential lock. When in the locked mode, the axle
shafts and the differential are locked together and there is no
differential action between the wheels.
Reference Only