Join Date: Mar 2005
Location: Under an invisibility cloak, somewhere in the Northeast
Subject: Rear Drive Axle Whine And Or Gear Noise
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Perceived gear noise or whine from the rear differential that may change with throttle input i.e.coasting or accelerating.
Any gear driven unit, especially an automotive drive axle where the engine torque multiplication occurs at a 90 degree turn in the driveline, produces a certain amount of noise. Therefore, an interpretation must be made for each vehicle in order to determine if the noise is normal or if a concern actually exists. A certain amount of noise must be expected and cannot be eliminated by conventional repairs or adjustment.
Normal axle noise can be described as a slight noise heard only at a certain speed or under unusual or remote conditions. For example, the noise tends to reach a peak at speeds from 40-60 mph (60-100 km/h) depending on road and load conditions, or on gear ratio and tire size. This slight noise is in no way indicative of trouble in the axle assembly.
A comparison should be made to a duplicate vehicle with similar mileage prior to attempting any repairs.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
INFORMATION POSTED ON SITE
Any Service Manual, Technical Service Bulletin, Priliminary Service Bulletin, Part, Accessory, Sales or Product information found here on site, should be thought of as correct and accurate as of the date it was posted. After that any information or service procedure should be confirmed as still correct with your dealership.
FAN MAIL TO ME: "Unfortunately, it’s attitudes like yours that give dealers a bad reputation."
Last edited by mceb; 08-02-2006 at 12:33 PM.