
A CAUTION: 
Shifting out of PARK (f) or NEUTRAL (N) while  your engine is 
“racing”  (running at high speed) is dangerous.  Unless your foot 
is firmly  on  the brake pedal, your  vehicle could move  very 
rapidly. 
You could  lose control  and hit people  or objects.  Don’t 
shift out  of 
PARK (P) or NEUTRAL (N) while  your engine is 
racing. 
NOTICE: 
Damage  to  your transmission caused  by shifting out of PARK 
(P) or NEUTRAL (N) with  the engine racing  isn’t  covered  by 
your warranty. 
AUTOMATIC  OVERDRIVE (a) - This  position  is for  normal 
driving.  If  you need more power  for passing,  and you’re: 
- Going  less  than about 35 mph (56 km/h), push your accelerator 
pedal  about  halfway  down. 
the  way  down. 
You’ll  shift down to the next  gear and have  more power. 
- Going  about 35 mph (56 kdh)  or more, push the  accelerator all 
0 should not be used  when  towing  a  trailer, carrying a heavy load, 
driving  on steep hills,  or for  off-road  driving.  Select  THIRD 
GEAR 
(3) when  operating  the  vehicle under any  of these 
conditions. 
THIRD  GEAR (3) - This is like 63, but you never  go into  Overdrive. 
You  should  use 
THIRD GEAR (3) when towing a trailer. carrying  a 
heavy  load,  driving on steep  hills,  or 
for off-road  driving. 
0 SECOND  GEAR (2) - This position  gives  you more power  but lower 
fuel  economy.  You can use 
SECOND GEAR (2) on hills.  It can  help 
control 
your speed  as you go down  steep  mountain roads, but then  you 
would also want 
to use your brakes  off and  on. 
If you  manually  select  SECOND GEAR (2), the transmission will drive 
in second gear. You may use this  feature  for  reducing  torque  to the  rear 
wheels  when  you are trying 
to start  your  vehicle from a stop on 
slippery road  surfaces. 
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NOTICE: 
Driving with the  parking  brake  on  can  cause  your  rear  brakes to 
overheat.  You may  have  to  replace  them,  and  you could  also 
damage  other  parts  of your  vehicle.  Always  check  to  be  sure 
your  parking  brake  is fully  released  before  you drive. 
If you  are towing  a  trailer  and  are  parking  on  any  hill:  See “Towing a 
Trailer” in the Index.  That section  shows what to do first  to keep the trailer 
from moving. 
Propshaft  Brake  Burnish  Procedure 
If you have  a 3500 HD model, it is  recommended  that  the  propshaft  mounted 
parking  brake  be  burnished 
as part  of  the  new  vehicle  break in. The  parking 
brake  will  work  best  after 
it has  been  burnished  following  these  instructions. 
Make 
10 (ten)  stops,  using the parking brake  foot pedal, from  20 mph (32 
km/h)  about 
2 1/2 miles (4 km) apart.  In between  stops, drive the vehicle  at 
20  mph  (32  km/h). 
Torque  Lock 
When parking,  the weight  of the vehicle  may  put  too  much force on the 
parking  pawl 
in the transmission.  It  may  be difficult to pull the selector 
lever out  of 
PARK (P). This is called ”torque  lock.” To find out how  to 
avoid torque  lock, see “Torque Lock” later  in this  section. 
Shifting  lnto PARK (P) (Automatic 
Transmission  Models  Only) 
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Leaving Your  Vehicle  With  the  Engine  Running 
(Automatic  Transmission  Models 
Only) 
A CAUTION: 
It  can  be dangerous to leave your  vehicle with the  engine 
running.  Your  vehicle  could  move  suddenly if the  shift  lever 
is 
not fully  in PARK (P) with the  parking  brake firmly set. If you 
have  four-wheel  drive with a manual  transfer case  shift  lever 
and  your  transfer  case  is in 
NEUTRAL  (N), your vehicle  will  be 
free to  roll,  even  if your shift lever  is  in PARK 
(P). So be sure  the 
transfer  case 
is in a drive gear - not  in NEUTRAL  (N). And, if 
you  leave  the vehicle  with  the engine running, it  could overheat 
and  even  catch  fire. 
You or others  could be injured.  Don’t leave 
your  vehicle  with  the engine  running  unless you have  to. 
If you  have to leave your vehicle with the engine  running,  be sure your 
vehicle  is  in  PARK  (P) and your parking brake  is firmly set before  you leave 
it. After  you’ve  moved the shift lever into the  PARK (P) position, hold the 
regular  brake pedal down. Then.  see 
if you can move the shift lever away 
from  PARK  (P) without first pulling 
it toward  you. 
If 
you can, it means that the shift lever wasn’t fully locked  into  PARK (P). 
Torque  Lock  (Automatic  Transmission) 
If you  are parking  on a hill and you don’t shift your transmission  into  PARK 
(P) properly, the weight of the vehicle  may put too much  force on the 
parking pawl  in the transmission. 
You may  find it difficult to pull the shift 
lever  out of  PARK  (P). This  is called  “torque lock.” To prevent torque  lock, 
set the parking brake and then shift  into PARK  (P) properly  before  you 
leave  the driver’s  seat. 
To find out  how, see “Shifting Into  PARK (P)” in the 
Index. 
When  you are ready to  drive, move the shift lever out 
of PARK  (P) before 
you release  the parking brake. 
If  “torque  lock” does occur, you  may need to have  another vehicle push 
yours 
a little uphill to take  some of the pressure from the transmission, so 
you  can pull the shift  lever out of  PARK (P). 
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Tighten Clockwise Tightening  Sequence 
t 
40 
Tighten the 
nuts firmly in a criss-cross sequence as shown. Rotate the  wheel 
wrench  clockwise. 
A CAUTION: 
Incorrect  wheel nuts or improperly tightened  wheel nuts can 
cause  the wheel  to become  loose  and even  come 
off. This  could 
lead to  an accident.  Be sure  to use  the correct  wheel  nuts. 
If you 
have to replace them,  be sure  to  get the  right kind. 
Stop somewhere 
as soon as you can  and  have the  nuts tightened 
with 
a torque  wrench  to  the  proper  torque. 
For proper  torque,  see “Wheel  Nut Torque” in the Index. 
Put  the wheel trim  back on. 
For vehicles with plastic wheel 
nut caps,  tighten the  caps until they are 
finger  tight,  then tighten them  an additional  one-half turn 
with the ratchet 
and wheel  wrench. 
Remove  any wheel  blocks. 
Remember,  the jack,  jacking  equipment  and tire must be properly  stored 
in 
their original  storage position before you begin driving  again.  The  next part, 
“Storing the  Tire and Jack,” 
will show  you  how. 
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If your  vehicle  has  dual  rear  wheels  and  the  load  range or tread design for 
your  front  tires  is different  from  your  rear  tires,  always  use  the correct 
rotation  pattern  shown  here  when rotating  your  tires.  The dual  tires  are 
rotated  as  a pair, and  the  inside  rear  tires  become  the  outside  rear tires. 
When  you install  dual  wheels, be  sure the vent  holes  in the  inner  and outer 
wheels 
on each  side  are  lined  up. 
After  the  tires  have  been  rotated,  adjust  the  front  and rear  inflation  pressures 
as  shown  on the  Certificatioflire  label.  Make  certain  that all  wheel  nuts are 
properly  tightened.  See  “Wheel  Nut Torque”  in the  Index. 
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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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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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Wheel Nut Torque 
MODEL 
C 1500 
K 1500 & C-K  2500 
C-K  2500 
(w/CGP) 
C-K 3500 
-Single  Rear  Wheels 
C3500 
-Dual  Rear  Wheels 
C3500 HD 
-Front 
-Rear 
DESCRIPTION 
5 bolts ( 14mm) 
6  bolts  (14mm) 
8 bolts ( 14mm) 
8 bolts ( 14mm) 
8 bolts  (14rnm) 
5 bolts (518 in.) 
10 bolts (5/8 in.) 
Cooling  System  Capacity 
ENGINE 
4.3L 
5 .OL 
5.7L 
6.5L 
6.5L 
6.5L 
7.4L 
7.4L  w/3500 
HD 
VIN 
Z 
H 
K 
P 
S 
F 
N 
N 
TORQUE 
120 ft.  lbs. (1 60 Nmm) 
120 ft. lbs. (160 Nmm) 
120 ft.  lbs.  (160  Nom) 
120 
ft. lbs. (1 60 Nom) 
140  ft.  lbs. ( 190 Nmm) 
175 ft. lbs.  (240 Nom) 
175 ft. lbs. (240 Nom) 
QUANTITY* 
13 Quarts  (12.3  Liters) 
17.5 Quarts  (16.6 
Liters) 
17.5  Quarts  (16.5 
Liters) 
23.5  Quarts  (22.2 
Liters) 
23.5  Quarts  (22.2 
Liters) 
23.5  Quarts  (22.2 
Liters) 
25 
Quarts (23.5 Liters) 
28.5 
Quarts (27  Liters) 
After  refill,  the  level 
MUST be  checked  as outlined  under  “Engine  Cooling 
System” 
in Section 5. 
*All quantities  are  approximate. 
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