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Downloaded from www.Manualslib.com manuals search engine A CAUTION: I 
Rust or  dirt  on a wheel, or on  the  parts  to which 
it  is  fastened,  can  make  wheel nuts become  loose 
after  a time.  The wheel  could  come 
off and cause 
an  accident.  When you change a  wheel,  remove 
any  rust  or  dirt  from places  where the wheel 
attaches  to  the  vehicle. In  an emergency,  you can 
use 
a cloth or a  paper  towel to do  this;  but  be 
sure  to  use 
a scraper  or  wire brush  later, if you 
need  to,  to get  all the  rust  or  dirt 
off. (See 
“Changing 
a Flat  Tire”  in  the  Index.)  When 
It’s Time 
for New Tires 
One way  to tell when  it’s 
time  for  new tires is  to 
check  the treadwear 
indicators,  which will 
appear  when your tires  have 
only 
1/16 inch  (1.6 mm)  or 
less  of tread remaining. 
Some  commercial truck 
tires  may not have 
treadwear indicators. 
You need a  new tire if any of the following statements 
are true: 
You can see the indicators at three  or more places 
around the tire. 
You can see cord  or fabric  showing through  the 
tire’s  rubber. 
The tread  or sidewall  is  cracked,  cut  or snagged  deep 
enough  to show cord  or fabric. 
0 The  tire has a bump,  bulge or split. 
The  tire  has a puncture,  cut  or other damage  that 
can’t  be repaired well because  of the  size  or  location 
of the damage. 
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        Page 273 of 376

Downloaded from www.Manualslib.com manuals search engine Dual Tire  Operation Buying  New  Tires 
To 
find  out  what kind and  size of tires  you need,  look  at 
the  Certificatioflire  label. 
When 
the vehicle  is new,  or  whenever a wheel,  wheel 
bolt  or  wheel  nut  is  replaced,  check  the  wheel  nut  torque 
after 
100, 1,000 and 6,000 miles (160,  1  600 and 
10 000 km) of  driving.  For  proper  torque,  see  “Wheel 
,Nut  Torque”  in the  Index. 
The  outer  tire  on  a  dual  wheel  setup  generally  wears 
faster  than the  inner  tire.  Your tires will wear  more 
evenly  and last  longer  if  you rotate  the  tires  periodically. 
If  you’re  going  to be  doing  a  lot  of driving  on 
high-crown  roads,  you can  reduce  tire  wear by adding 
5 psi (35 kPa)  to the  tire  pressure  in the  outer  tires.  Be 
sure  to  return to the  recommended  pressures  when no 
longer  driving  under  those  conditions.  See  “Changing  a 
Flat  Tire” in  the  Index  for  more  information.  The  tires  installed  on  your 
vehicle when it was  new  had 
a Tire Performance  Criteria  Specification  (TPC Spec) 
number  on each  tire’s  sidewall.  When  you get new  tires, 
get  ones  with that  same  TPC  Spec  number. That way 
your  vehicle will  continue to have  tires  that are  designed 
to  give  proper  endurance,  handling,  speed  rating, 
traction,  ride and  other  things during  normal service on 
your  vehicle.  If your  tires  have  an  all-season  tread 
design,  the TPC  number  will be followed  by an 
“MS” 
(for  mud and  snow). 
11 you ever  replace  your  tires  with those  not having  a 
TPC  Spec  number, make  sure they are  the  same  size, 
load  range,  speed rating  and  construction  type (bias, 
bias-belted  or  radial) as your  original  tires. 
If you  operate  your  vehicle  with  a  tire  that  is 
badly  underinflated,  the  tire  can  overheat.  An 
overheated  tire  can  lose  air  suddenly  or  catch 
fire. 
You or  others  could  be  injured.  Be  sure  all 
tires  (including  the  spare)  are  properly  inflated. 
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Downloaded from www.Manualslib.com manuals search engine I ' A CAUTION: 
Mixing tires could  cause  you to lose  control  while 
driving.  If you  mix  tires of different  sizes or types 
(radial  and  bias-belted tires),  the vehicle  may  not 
handle properly,  and you  could  have 
a crash. 
Using  tires 
of different  sizes  may  also cause 
damage  to your  vehicle.  Be  sure 
to use the same 
size  and  type  tires  on 
all wheels. 
Uniform Tire Quality Grading 
The following  information relates to the system 
developed  by the United States National Highway 
Traffic Safety Administration,  which grades tires  by 
treadwear, traction and  temperature performance.  (This 
applies 
only to vehicles sold  in the United States.)  The 
grades are  molded  on  the sidewalls 
of most  passenger 
car  tires.  The Uniform Tire Quality Grading system does 
not  apply 
to deep  tread, winter-type  snow tires, 
space-saver  or temporary use  spare tires, tires with 
nominal rim diameters  of 
10 to 12 inches (25 to 30 cm), 
or 
to some limited-production  tires. 
While the tires available on General Motors passenger 
cars  and light trucks  may vary with respect 
to these 
grades, 
they must also conform to Federal  safety 
requirements  and additional  General Motors Tire 
Performance Criteria (TPC) standards. 
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Downloaded from www.Manualslib.com manuals search engine Tire Chains 
NOTICE: 
~~ 
Use tire chains  only  where  legal  and only when you 
must.  Use chains that are the proper  size for your 
tires.  Install  them  on the  tires  of the  rear  axle. 
Tighten  them  as tightly  as possible  with  the  ends 
securely  fastened.  Drive  slowly  and 
follow the chain 
manufacturer’s  instructions. 
If you can  hear the 
chains  contacting  your vehicle,  stop and  retighten 
them. 
If the  contact  continues,  slow  down until  it 
stops.  Driving 
too fast  or spinning  the  wheels  with 
chains  on  will damage your  vehicle. 
Appearance  Care 
Remember, cleaning  products can be hazardous.  Some 
are  toxic.  Others  can burst  into  flame if 
you strike a 
match  or  get them 
on a hot part of the  vehicle.  Some are 
dangerous  if you  breathe their  fumes in 
a closed space. 
When  you  use  anything  from  a  container 
to clean your 
vehicle,  be sure 
to follow the manufacturer’s  warnings 
and instructions.  And always  open your doors  or 
windows  when you’re cleaning the inside. 
Never use these to clean your vehicle: 
0 Gasoline 
0 Benzene 
0 Naphtha 
Carbon Tetrachloride 
0 Acetone 
0 Paint  Thinner 
0 Turpentine 
0 Lacquer  Thinner 
0 Nail Polish Remover 
They can 
all be  hazardous -- some  more than 
others 
-- and  they  can all  damage  your vehicle, too. 
Don’t  use  any of these unless this manual says 
you can. 
In many  uses, these will  damage your vehicle: 
0 Alcohol 
0 Laundry Soap 
0 Bleach 
0 Reducing Agents 
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