PREVOST X3-45 COMMUTER User Manual

SECTION 10: FRONT I-BEAM AXLE
14
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual First release Oct 2020
FIGURE 4: CAMBER
The camber angle is not adjustable. Camber
variations may be caused by wear at the wheel
bearings, steering knuckle pins or by a bent
knuckle or sagging axle center. Steering effort is
affected by improper camber, and uneven tire
wear will result. Excessive positive camber
causes an irregular wear of tire at the outer
shoulder and excessive negative camber causes
wear at the inner shoulder.
7.6.1 Camber Check
For camber specifications, refer to paragraph
8: ‘’ ALIGNMENT SPECIFICATIONS’’ in this
section
1. Use an alignment machine to check the
camber angle.
2. If camber reading is not in the specifications,
adjust the wheel bearings and repeat the
check. If the reading is still not within
specifications, verify the steering knuckle
pins and axle center.
3. Check the wheel lateral distortion as
instructed in Section 13, ‘’Wheels, Hubs and
Tires’’ under heading, ‘’Checking for
Distorted Wheel on Vehicle’’. If distortion is
excessive, straighten or replace wheel(s).
7.7 FRONT AXLE CASTER
For caster specifications, refer to paragraph
8: ‘’ALIGNMENT SPECIFICATIONS’’ in this
section.
Positive caster is the rearward tilt from the vertical
axis of the knuckle pin. Negative caster is the
forward tilt from the vertical axis of the knuckle pin
(Figure 5). This vehicle is designed with a positive
caster. The purpose of the caster angle is to give
a trailing effect. This results in stabilized steering
and a tendency for the wheels to return to the
straight-ahead position after taking a turn.
Excessive caster results in hard steering around
corners. A shimmy may also develop when
returning to the straight ahead position (pulling out
of curves).
FIGURE 5: CASTER
Insufficient caster will cause wandering and
steering instability. Caster variations may be
caused by a bent axle, tilting or distortion of the
side suspension supports, damaged radius rod
bushings, or unequal tightening of the front and
rear suspension support bolts. Incorrect caster
must be corrected by replacing the damaged
suspension parts. A precision instrument should
be used to measure the caster.
NOTE
The caster of this vehicle is factory set and is
not adjustable. However, if after replacing
damaged parts or in case of improper caster
due to irregular setting
, the front axle caster
needs adjustment; it can be adjusted by means
of shims (Prevost #110663) on the left-hand
side upper radius rod support in order to obtain
minor adjustment.
7.8 FRONT WHEEL TOE-IN
Wheel toe-in is the degree (usually expressed in
fractions of an inch) where the forward part of the
vehicle front wheels are closer together than the
rear part, measured at wheel centerline height

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in