Front And Tag Axle Wheel Studs; Hub Mounted Wheels; Care Of Wheels; Tag Axle Wheel Hubs - PREVOST H3-41 Maintenance Manual

7.2 FRONT AND TAG AXLE WHEEL STUDS

Wheel is hub mounted on front and tag axle
(M22x1.5 thread).
FIGURE 6: SINGLE WHEEL
NOTE
Wheel studs and nuts must be kept free from
grease and oil. No lubricant whatsoever should
be used.

8. HUB MOUNTED WHEELS

Wheel surfaces in contact with hubs, nuts or
other wheels should be kept free of all rust,
grease and paint (except for initial "E" coat
protection, applied to stop rusting and to facilitate
wheel removal). The reason for this is to assure
that all faces are clamped together without
buildup of any coating. The threads of the wheel
studs and the wheel nuts should be clean and
undamaged.
NOTE
When painting wheels, make sure to mask all
surfaces identified above.
Using a calibrated torque wrench, tighten wheel
nuts. Do not use power tools or long bars for
tightening. Tighten wheel nuts alternately as
shown in figure 3.
TORQUE: 450-500 lb-ft (610-678 Nm)
SECTION 13: WHEELS, HUBS AND TIRES
NOTE
Tightening should not be done immediately
after prolonged braking or when wheel ends
are hot.
Check wheel nut torque at every 100 miles (160
km) for 500 miles (800 km) after fitting wheels.
Let cool before checking. If any relaxation of the
initial torque has occurred, retighten. Relaxation
of initial torque may occur because of the
"bedding down" of the hub and wheel surfaces.
NOTE
Torque relaxation occurs when wheel ends are
hot but should revert to original setting when
cool. Retightening when hot will produce a
higher torque reading than recommended.

8.1 CARE OF WHEELS

Check for cracks in wheels, especially around
the fixing holes, studs, nuts and washers. If in
doubt, renew.
Do not simply retighten very loose wheel fixings
or wheels that are continually becoming loose.
Find out why they are loose and whether any
damage has been caused.
Use trained personnel and keep records of all
attention to wheels and fixings, including which
parts were renewed and when.

9. TAG AXLE WHEEL HUBS

The FAG unitized hub bearings used on the tag
axle are non-serviceable items. Bearings are pre-
adjusted, lubricated and have seals fitted as part
of the manufacturing process. The bearings are
greased for life and there is no need or facility for
re-lubrication.
PA1621 Maintenance Manual All Series | January 2017
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