Our EXT 2002 (AWD) started making this grinding noise in the front axle, it has been making it for the past two months and it seems to be getting louder, you can hear it better at low speeds 0-40 MPH....I'm concern this is a serious problem and could I damage the car by driving it in this condition?

When we took it to a tire checkup the mechanic told me it was "lack of Grease in the front Axle"...does everyone here agree?

Thanks to all for helping with advice

__________________________________________________ ___________
I have been sent the following advice below:

Whine Noise From Front Axle (Diagnose and Replace Front Propeller Shaft with a Tuned Internally Dampened Front Propeller Shaft) #03-04-17-005 - (Mar 13, 2003)
Whine Noise from Front Axle (Diagnose and Replace Front Propeller Shaft with a Tuned Internally Dampened Front Propeller Shaft)
2002-2003 Cadillac Escalade, Escalade EXT

2000-2003 GMC Yukon Denali, Yukon XL Denali

2001 GMC Sierra C3

2002-2003 GMC Sierra Denali

with AWD Transfer Case (RPO NP3 or NR3)

Condition
Some customers may comment on a slight whine noise from the front of the vehicle during light throttle conditions, typically at two vehicle speed ranges of 64-80 km/h (40-50 mph) and 112-129 km/h (70-80 mph).

Cause
"Inherent" ring and pinion gear whine.

All gear driven units, such as automotive rear axles, produce some level of noise that cannot be eliminated with conventional adjustments and repairs. "Inherent" axle noise can be described as a slight noise heard only at a certain speed on most General Motorsฎ trucks. The presence of this noise is not indicative of a functional concern with the axle assembly. However, some customers may find that this "inherent" axle noise is unacceptable.

Correction
Replace the front propeller shaft with an internally tuned dampened shaft ONLY after diagnosis concludes that it is an "inherent" front axle noise and no physical damage or incorrect adjustment exists.


Diagnostic Information and Procedure for Front Axle Noise


• Diagnostic Starting Point - Front Drive Axle (Refer to SI Do***ent ID #696970).

• Symptoms - Front Drive Axle (Refer to SI Do***ent ID #696957).

• Front Drive Axle Noises (Refer to SI Do***ent ID #700621).

• Noisy in Drive (Refer to SI Do***ent ID #700622).

• Noisy When Coasting (Refer to SI Do***ent ID #700624).

• Intermittent Noise (Refer to SI Do***ent ID #700625).

• Constant Noise (Refer to SI Do***ent ID #700631).

• Noisy on Turns (Refer to SI Do***ent ID #700634).


Front Propeller Shaft Replacement


Raise the vehicle. Refer to Lifting and Jacking the Vehicle (SI Do***ent ID #737171).
Important: Before disassembly, observe and accurately mark all of the driveline components relative to the propeller shaft and to the axles. These items include the following components:


• The propeller shafts

• The wheel drive shafts

• The pinion flanges

• The output shafts

Assemble all of the components in the exact relationship to each other prior to removal. Observe all published specifications and torque values and any measurements obtained prior to disassembly.


Remove the transfer case shield, if equipped.



Remove the clamp (if applicable) (4) at the transfer case (3) by prying up the exposed end of the clamp (4) with a flat-bladed tool.



Remove the bolts (6) and the yoke retainers (7) from the front axle pinion yoke (1).
Notice: When removing the propeller shaft, do not attempt to remove the shaft by pounding on the yoke ears or using a tool between the yoke and the universal joint. If the propeller shaft is removed by using such means, the injection joints may fracture and lead to premature failure of the joint.

Disconnect the propeller shaft (2) from the front axle pinion yoke (1).
Remove the propeller shaft (5) from the transfer case output shaft by sliding the propeller shaft forward.
Inspect the splines of the transfer case output shaft for a sufficient coating of lubricant. If the output shaft does not have a sufficient coating of lubricant, lubricate the shaft with lubricant, P/N 12345879 (Canadian P/N 10953511), or with an equivalent lubricant meeting GM specification 9985830.
Important: Some old driveshaft boots may only use a single clamp design. When installing the new propeller shaft, use ONLY a two clamp boot.


Install the new clamp, P/N 26064275, supplied with the new propeller shaft, P/N 15186002, into the groove of the propeller shaft boot.
Install the propeller shaft splines into the transfer case output shaft.
Install the propeller shaft to the front axle pinion yoke.
Install the yoke retainers and the bolts.

Tighten
Tighten the yoke retainer bolts to 25 N•m (19 lb ft).

Install the boot onto the transfer case output shaft until the boot is attached into the groove on the output shaft.



Using the J 43218 , crimp the clamp until the dimensions that are shown are obtained.
Install the transfer case shield, if equipped.
Install the transfer case shield mounting bolts, if equipped.

Tighten
Tighten the transfer case shield mounting bolts to 20 N•m (15 lb ft).

Lower the vehicle.
Parts Information
Parts are in limited quantities. DO NOT order parts for stock.

Part Number
Description
Qty

15186002
Propeller Shaft, Front
1


Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

F1200
Propeller Shaft, Front Of Transfer Case - Replace
Use published labor operation time




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.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


ฉ Copyright General Motors Corporation. All Rights Reserved.
__________________
04 Cad Ext
01 Trans Am Ws6
03 MB ML350
96 Hda Civic SiR
91 Lxs Ls400
86 TyA Mr2

 

Change front diff fluid note what color it is - black or gray - diff needs to come out a part. will need at least bearings. Light brown - most likely ok unless metal build up on magnet on drain plug. Tires typically will get louder with speed.