SECTION 13: WHEELS, HUBS & TIRES
6
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version
‒
Rev.2 April 2016)
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 to 450 - 500 lbf-ft (610 - 680 Nm) of torque.
Do not use power tools or long bars for
tightening. Tighten wheel nuts alternately as
shown in Figure 2.
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 450 - 500 lbf-ft (610 - 680 Nm) of 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.
6.1 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.
7. 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.
