differential GMC SIERRA 2005 Owner's Manual

Page 454 of 574

When to Change Lubricant
Refer to the Maintenance Schedule to determine how
often to change the lubricant. SeeScheduled
Maintenance on page 6-4.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids
and Lubricants on page 6-14.
Front Axle
When to Check Lubricant
It is not necessary to regularly check front axle uid
unless you suspect there is a leak or you hear an
unusual noise. A uid loss could indicate a problem.
Have it inspected and repaired.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the ller plug hole,
located on the front axle, you may need to add some
lubricant:
When the differential is cold, add enough lubricant to
raise the level to 0 to 3/8 inch (9.5 mm) below the
ller plug hole.
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Page 455 of 574

When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of the ller plug hole.
What to Use
To determine what kind of lubricant to use see
Recommended Fluids and Lubricants on page 6-14.
Noise Control System
Tampering with Noise Control
System Prohibited
The following information relates to compliance with
federal noise emission standards for vehicles with a
Gross Vehicle Weight Rating (GVWR) of more than
10,000 lbs (4 536 kg). The Maintenance Schedule
provides information on maintaining the noise control
system to minimize degradation of the noise emission
control system during the life of your vehicle. The noise
control system warranty is given in your warranty booklet.
These standards apply only to vehicles sold in the
United States.Federal law prohibits the following acts or the causing
thereof:
1. The removal or rendering inoperative by any
person, other than for purposes of maintenance,
repair or replacement, of any device or element of
design incorporated into any new vehicle for
the purpose of noise control, prior to its sale or
delivery to the ultimate purchaser or while it is in
use; or
2. The use of the vehicle after such device or element
of design has been removed or rendered inoperative
by any person.
Among those acts presumed to constitute tampering are
the acts listed below.Insulation:

Removal of the noise shields or any underhood
insulation.
Engine:

Removal or rendering engine speed governor
(if equipped) inoperative so as to allow engine
speed to exceed manufacturer specications.
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