Front Axle
The front axle engages and disengages automatically when you shift the transfer case. Some delay for the axle to engage or disengage is normal.
See also:
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during severe operating conditions.
See Engine Overheating on page 10‑20. ...
Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Or every two years, whichever comes first.
b) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properl ...
New for 2011
The Sierra Hybrid gets GM's OnStar 9.0 telematics system that GM says
provides better voice recognition. GM also said they have worked to cut down on
the amount of wind noise occupants hear. ...