possible bushing in you suspension, swaybars, shock bushings, bad shocks. if it happens at slow speeds, get another person to listen for it as you drive and try to focus on the area. should be able to locate it if that's the case. or try pushing down on the bumpers to simulate bumps and listen for the sound.
If it is like mine--the squeaking will eventually occur all of the time while driving. I had to change the universal joints on the drive shaft at 70,000 miles. GM should be ashamed, with gas prices as high as they are, every mile on this truck has been driven gently.
Check your universal joints!
It is important to know the weight of a vehicle while driving it. A 2007 Chevy Avalanche has a gross vehicle weight of 5,742 pounds.
40 on idle up to 60 while on the move.
If it squeaks while it moves but not while it's at idle then the squeaks are body or suspension noise.
The drive belt may be slipping or going bad.
The 2005 Chevy Avalanche does not come equipped with a cabin air filter. While some later models and different vehicles may include this feature, the Avalanche from that year was designed without a cabin air filtration system. If you're looking to improve air quality within the cabin, you might consider alternative options like periodic cleaning of the ventilation system.
To put a Chevy Trailblazer into four wheel driver, locate the four wheel drive component below the instrument panel. While the car is in drive, move the knob into the desired four-wheel drive position.
check refrigerant level. if is ok,, replace the low presion swicht locate on acumulator.
possible have a bad master cylinder
You most likely have a leaking heater core, check you coolant level first while the truck is cool........
To remove the headrest on a 2005 Chevy Avalanche, first, locate the release buttons on the sides of the headrest posts. Press and hold these buttons while pulling upward on the headrest to detach it from the seat. If the headrest doesn't come off easily, ensure that the buttons are fully depressed. Once removed, you can reinstall it by aligning the posts and pushing it back into place until it clicks.