The 45,000 miles would put the rear diff out of factory warranty. Here is what the problem is.
#PIP3916B: Resonating Vibration Type Noise While Driving From The Rear Of Vehicle - keywords drone moan - (Dec 17, 2007)
|Subject:||Resonating Vibration Type Noise While Driving From the Rear of Vehicle|
|Models:||2006 Chevrolet Equinox|
|Equipped with All Wheel Drive|
This PI is being superseded to update repair instructions and add part numbers. Please discard PIP3916A
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Drone, moan, rotational, resonation type vibration noise from the rear of the vehicle that can be at any speed but is generally most noticeable at 35-50 mph (56-80 kph). The noise may be described as a "helicopter" type noise.
Isolate the noise to the RDM (rear drive module) by driving the vehicle with the rear prop shaft removed, then swapping a prop shaft from a known good vehicle.
If the noise can be isolated to the RDM replaced the clutch drum with updated stock from GMSPO.
2006 Equinox and Torrent: part number 19177885
2006-2007 Vue part number 19177886
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.