GMC 4000 Series Service Manual page 518

Wheels used on vehicles covered in this manual
are D isc, Cast, or Budd type (fig. 1). Disc wheels
are secured on hub studs with nuts. Budd type front
wheels have a single nut, while rear wheels have
inner and outer nuts. On cast steel wheels, tires
are mounted on rims which are secured on wheel
with rim clamps, studs, and nuts.
WHEEL NUT TORQUE CHECK
IMPORTANT: When truck is new, or after
wheel has been changed, the wheel nut torque should
be checked at 100, 500, 1000 m iles, and every 1000
m iles thereafter.
TIGHTENING WHEEL STUD NUTS
- DISC AND BUDD WHEELS
IMPORTANT: On all type wheels never use
oil or grease on studs or nuts. When installing dual
rear tires, valve stem s should be positioned 180
degrees apart.
When Budd type wheels are used, studs and
DISC TYPE WHEELS
G M C S E R V I C E M A N U A L
SECTION 10
'Wheels
C u n d
Figure 1— Typical Disc, Budd, a n d Cast W heels
^ine.6.
nuts on right side of vehicle have right-hand
threads, and studs and nuts on left side have left-
hand threads. Inner and outer nuts are stamped
"L" or "R" to indicate at which side of vehicle they
are to be used.
To tighten nuts on Budd type dual rear wheels
(fig. 1) loosen outer nuts, then tighten inner nuts.
Tighten opposite nuts alternately so wheel will be
square against hub flange. After tightening inner
nuts, tighten outer nuts. When replacing 10 hole
wheels the tightening sequence shown in figure 2
should be used. Tighten nuts numbers 1, 2, 3, and
4 in sequence indicated. Draw nuts up alternately,
a little at a time until torque of approximately 200
foot-pounds is reached. Tighten the balance of nuts
to 450 to 500 foot-pounds, while alternating from
sid e-to-sid e of wheel. Finish tightening nuts 1, 2,
3, and 4 to 450 to 500 foot-pounds.
CAST SPOKE WHEELS (Refer to Fig. 3)
1. Install rim clamps and nuts finger-tight.
BUDD TYPE WHEELS
Sec. 10
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