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Jack  and Jacking  Tool  Storage - Chassis  Cab  Models 
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Jacking  Tool  Storage - Chassis  Cab  Models 
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3 
3 
1. Nut 
2. Jack  Handle Extension 
3. Wheel  Wrench 
4. Jack  and  Tool Storage  Box 
5. Ratchet 
6. Jack  Handle 
7. Tool Retainer 
8, Jack 
To Remove  the  Spare  Tire 
The  spare  tire, if you have one, is full size like the other  tires on your 
vehicle. 
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When it’s Time for  New  Tires 
You need a new  tire if: 
Tread  Wear 
Indicators 
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. 
0 You  can see the indicators  at three  or more places around  the tire. 
0 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. 
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. 
Dual Tire  Operation 
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. 
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A CAUTION: 
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, if any)  are properly  inflated. 
Buying New Tires 
To find out what  kind and size  of tires  you need, look  at the 
CertificationRire  label. 
The  tires  installed  on your  vehicle when 
it was new  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). 
If  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. 
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. 
Be sure  to  use the same  size and  type  tires  on all four  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.) 
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Whenever a wheel, wheel bolt or wheel nut is replaced on a dual wheel 
setup, 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. 
Used Replacement Wheels 
A CAUTION: 
Putting a used  wheel  on your  vehicle is dangerous. You can’t 
know 
how it’s  been  used  or how  many  miles  it’s  been  driven. It 
could  fail suddenly  and cause  an accident. If you have  to replace 
a wheel  use a new GM original equipment  wheel. 
7 
c 
‘ire Chains 
NOTICE: 
If your  vehicle  has dual  wheels  or LT265/75R16 size  tires,  don’t 
use  tire  chains;  they  can damage your  vehicle. 
If you  don’t  have dual wheels  or if  you  have a tire size  other 
than 
LT26975R16, 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. 
Don’t  use  chains on the  tires 
of the  front  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. 
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