PREVOST X3-45 COMMUTER User Manual

SECTION 13: WHEELS, HUBS AND TIRES
12
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual | Section 13 revised Jan 2022
8.1 TAG AXLE HUB UNITIZED BEARING
INSPECTION
MAINTENANCE
Tag axle unitized bearing
Unitized bearing inspection should be made at
the intervals specified by the Lubrication And
Servicing Schedule in Section 24:
LUBRICATION & SERVICING..
1. Apply parking brake, raise wheels off the
ground and support axle on stands.
2. When the wheels are raised, they should
revolve quite freely without roughness.
3. Place magnetic base of a dial indicator on
brake caliper and position dial indicator stem
against a convenient marked spot on face of
hub flange.
4. With dial indicator in position pull hard but
steadily on hub flange and oscillate at same
time until a steady reading is achieved.
5. Without releasing the pressure, turn bearing
so that dial indicator stem contacts marked
spot and note reading on indicator.
6. Push bearing flange hard and oscillate as
before until a steady reading is achieved.
7. Without releasing the pressure, turn bearing
so that indicator stem again contacts the
marked spot and note new reading on
indicator.
8. The difference between readings is the
amount of mounted end play in bearing unit.
9. Refer to the following table for allowed end
plays:
New Tag Axle Unitized Hub Bearing Axial
Endplay
Maximum axial
clearance/end
play
0.0024 inch (0.061mm) based
on clamp load of 20000 lbf (90
kN).
Tag Axle Unitized Hub Bearing Axial
Endplay In Service
• If the endplay is between 0 – 0.002 in (0 – 0.05
mm), the inspection is complete.
•
If the endplay is greater than 0.002 in (0.05
mm), but less than 0.008 in (0.20mm), check
and retighten the wheel bearing adjusting nut.
Again check endplay to make sure that the
clamping process is done properly.
• If the endplay is equal to or greater than 0.008 in
(0.20mm), replace the unitized hub bearing as
soon as possible since the hub assembly may
not be safe to operate.
8.2 TAG AXLE HUB BEARING REMOVAL
1. Stop engine and apply parking brake.
2. Loosen wheel nuts about one turn (do not
remove the nuts). This is not necessary if
equipped with hydraulic powered gun.
3. Raise the vehicle by its jacking points on the
body. See Section 18, "Body", under
heading "Vehicle Jacking Points".
4. Unscrew 10 wheel hex stud nuts and
remove the wheel.
5. Unscrew 14 hub flange hex cap screws.
Applicable to the tag axle serrated screws:
discard hub flange cap screws (single-use
only).
NOTE: The following steps are similar to the
front axle hub bearing removal procedure. The
following images are generic images and do not
show the tag axle hub but they remain
representative of the following steps.
6. Loosen but do not remove the hub flange
bolts.
7. Remove 2 diametrically opposed hub flange
bolts.

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