
Other Service Items
Fuel Filter
Fuel Filter/Pressure Regulator
(Gasoline Engines)
The steel fuel filter/pressure regulator is located near
the engine compartment on the driver’s side frame rail.If your vehicle has a rear steel fuel tank, the fuel
filter/pressure regulator is located near the rear fuel
tank, on the driver’s side frame rail. SeeScheduled
Maintenance on page 6-5for recommended service
intervals.
If your vehicle is equipped with the optional Davco
spin-on type filter, it is located on the driver’s side
frame rail.
Fuel Filter (Diesel Engines)
If you have a diesel engine, your fuel filter is located in
the engine compartment on the driver’s side of the
vehicle, or along the driver’s side frame rail. See “Fuel
Filter Replacement” earlier in this section for further
information.
Also seeScheduled Maintenance on page 6-5for
recommended service intervals.
5-70

Front Wheel Bearings with
Oil-Filled Hubs
Notice:If you drive your vehicle through deep
water that is higher than the front or rear axle, water
may enter the axle housing and cause the axle
lubricant to break down. This could damage
the gears inside. Avoid driving your vehicle through
deep water.
You should avoid driving your vehicle through deep
puddles or standing water. If you must drive through
water that is higher than the front or rear axle, see your
dealer immediately afterward to have the condition of
the axle lubricant checked.If your vehicle has oil-filled
hubs, occasionally check
to see if they have enough
oil. You can tell if there
is oil there by using
the circular gage on the
sight glass.
If there isn’t, clean the rubber fill plug in the center of
the glass, and then remove it. Be careful not to
allow any dirt or water to get into the oil. Add enough of
the recommended oil to bring it up to the level mark
that you’ll see on the glass.
Refer to your Maintenance Schedule for the proper oil
to use.
When you fill the hub, check the glass again after
driving a short distance. It takes a while for the oil to
flow through the system, and you may find that you have
to add a little more to fill it to the proper level. Be sure
not to overfill the hub.
5-73

{CAUTION:
If wheel studs are damaged, they can break. If
all the studs on a wheel broke, the wheel could
come off and cause a crash. If any stud is
damaged because of a loose-running wheel, it
could be that all of the studs are damaged. To
be sure, replace all studs on the wheel. If the
stud holes in a wheel have become larger, the
wheel could collapse in operation. Replace any
wheel if its stud holes have become larger or
distorted in any way. Inspect hubs and
hub-piloted wheels for damage. Because of
loose running wheels, piloting pad damage
may occur and require replacement of the
entire hub, for proper centering of the wheels.
When replacing studs, hubs, wheel nuts or
wheels, be sure to use GM original equipment
parts.
{CAUTION:
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 a crash. 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.
How Often to Check
Wheel tightness is so important you should have a
technician check nut tightness on all wheels with
a torque wrench after your first 100 miles (160 km), and
then 1,000 miles (1 600 km) after that. Be sure to
repeat this service whenever you have a tire removed
or serviced. SeeScheduled Maintenance on page 6-5
for further information.
5-80

Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, floor pan,
and exhaust system even though they have corrosion
protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on the vehicle. This damage can
take two forms: blotchy, ring-shaped discolorations,
and small, irregular dark spots etched into the
paint surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.
Vehicle Care/Appearance Materials
Description Usage
Polishing Cloth
Wax-TreatedInterior and exterior
polishing cloth.
Tar and Road Oil
RemoverRemoves tar, road oil and
asphalt.
Chrome Cleaner
and PolishUse on chrome or
stainless steel.
White Sidewall
Tire CleanerRemoves soil and black
marks from whitewalls.
Vinyl Cleaner Cleans vinyl.
Glass CleanerRemoves dirt, grime,
smoke and fingerprints.
Chrome and Wire Wheel
CleanerRemoves dirt and grime
from chrome wheels and
wire wheel covers.
Finish EnhancerRemoves dust,
fingerprints, and surface
contaminants. Spray on
wipe off.
Swirl Remover PolishRemoves swirl marks,
fine scratches and other
light surface
contamination.
5-90

ApplicationCapacities
English Metric
23082T (H25) 44.0 pt 20.8 L
26080T (GJ4) 44.0 pt 20.8 L
Transfer Case (Four-Wheel Drive) 4.0 pt 1.9 L
Transmission Fluid, Automatic
3000 RDS and EVS, and 3500 RDS and EVS 52.0 pt 24.6 L
1000 HS, RDS, MH, PTS and EVS, 2200 HS, RDS, MH,
PTS and EVS, 2500 HS and RDS, and 2300 HS and RDS35.0 pt 13.5 L
Add 2 pints (1 L) when changing spin-on or remote filter.
See the Allison
®Automatic Transmission Operator’s Manual for fluid check and maintenance information.
Transmission Fluid, Manual
FS5205A, FS5205C 11.6 pt 5.5 L
FS6305A, FS6305B, 18.4 pt 8.7 L
FS5406, FSO8406 18.5 pt 8.8 L
RT6609 12.5 pt 5.9 L
RT8709B 25.1 pt 11.8 L
RT8908LL 29.1 pt 13.8 L
ZF S6-650 12.7 pt 6.0 L
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck the fluid level after filling.
5-103