GMC 1982 Light Duty Truck Service Manual page 400

3E-8 WHEELS A N D TIRES
until one nut is at the top of the bolt circle; tighten the nut
just snug. Snug up the rem aining nuts criss-cross to
minimize runout, then tighten the nuts to the recommended
torque alternately and evenly to avoid excessive runout.
CAUTION: Before re-installing wheels, remove
any build up of corrosion of the wheel mounting
surface and brake drum or disc mounting surface
by scraping and wire brushing. Installing wheels
without good metal-to-metal contact at the
mounting surfaces can cause wheel nuts to loosen
which can later allow a wheel to come off while
the vehicle is moving, possibly causing loss of
control.
Dual Wheels
W hen installing wheels on vehicles with dual rear
wheels:
1. Install inner and outer wheel and clamp ring on rear, or
wheel and clamp ring on front (be sure pins on clamp
ring face outboard).
2. Install and snug nuts finger tight.
3. Torque nuts to specified torque in sequence shown in
Fig. 3E-9.
Lateral runout should not exceed 1/8" on front wheel
or 3/16 " on rear wheel.
Attachment of Dual Wheels On P30 Models
To assure secure attach m ent of the dual disc wheels, it
is important that all dirt or rust scale be removed from the
mating surface of the wheels, hub, and clamp ring as well as
the stud and nut. P O W E R
M A N U A L L Y I N S P E C T T O R Q U E A T 130-180 FT.
LBS. M A N U A L T O R Q U E O N L Y : 150-200 FT. LB.
Inspection for Leaks
1. With wheel assembly removed from vehicle, inflate the
tire to recommended operating pressure.
2. Check for leaks at rim bead by placing wheel and tire
horizontal and allowing w ater to stand in groove
between rim and tire. Check for other leaks by lowering
assembly into water tank or running water over tire.
Installing Synthetic Tubes
NOTICE: W hen tube and flap are not properly
lubricated and mounted, they will stretch thin in the
tire bead and rim region. This will cause prem ature
failure.
D R IV E N U T S T H E N
1. Before installing tube in tire, clean inside of casing
thoroughly.
2. Insert tube in tire and inflate until it is nearly rounded
out.
3. Inspect rim for rust scale and bent flanges-clean rust
scale and straighten flanges where necessary.
4. Using a brush or cloth swab, apply a solution of neutral
vegetable oil soap to the inside and outside of tire beads
and also the the rim side of the tube. Do not allow soap
solution to run down into tire.
5. When mounting tire and tube on a drop center rim,
follow the standard procedure. Be sure tire is centered
on rim so that beads are out of rim well before inflating.
Do not allow tire to hang loosely on wheel while
inflating.
6. Center valve and pull it firmly against the rim. Hold in
this position and inflate until tire beads are firmly
seated on rim against flanges.
7. Completely deflate tire by removing valve core.
8. Reinflate tire to recommended pressure.
TUBELESS TIRES
Tubeless tires mounted on one piece full drop center
rims are standard on most trucks.
Mounting and Demounting
Use a tire changing machine to mount or demount
tires. Follow the equipment m anufacturer's instructions. Do
not use hand tools or tire irons alone to change tire as they
may damage the tire beads or wheel rim.
Rim bead seats should be cleaned with a wire brush or
coarse steel wool to remove lubricants, old rubber, and light
rust. Before mounting or demounting a tire, the bead area
should be well lubricated with an approved tire lubricant.
After mounting, inflate to 40 psi so that beads are
completely seated.
CAUTION: Do not stand over tire when inflating.
Bead may break when beads snaps over safety
hump and cause serious personal injury.
CAUTION: Do not exceed 275 kPa (40 psi) pressure
when inflating. If 275 kPa (40 psi) pressure will
not seat beads, deflate, re-lubricate and reinflate.
Overinflation may cause the bead to break and
cause serious personal injury.
Install valve core and inflate to proper pressure. Check
the locating rings of the tire to be sure they show around the
rim flanges on both sides (Fig. 3 E -10).
RADIAL TIRES
Recom m ended truck tire m ounting and inflation
procedures are especially important with radial truck tires.
Failure to follow these recommendations can cause bead
deformation in both tube type and tubeless tires due to
incorrect bead seating. Bead deform ation may lead to
chafing, lower sidewall and bead area cracking, demounting
difficulties, eccentric wear, ride vibration
retreadable casing.
Mounting
To insure correct mounting and bead seating and to
prevent bead deform ation, the following steps must be
taken:
and non-