2003 Denali front axle whine

[z0lt3c]

I recenlty picked up a pre-owned 03 yukon denali and I soon noticed it was making a loud whining noise from the front end. The noise starts around 35-40mph and it as it's loudest around 45mph and then about around 70-80. It mainly happens when I am pressing down on the accelator, or braking hard, but is also presenty to a lesser extent when simply coasting in those speed ranges.

 

I had the GM service department look at it before I picked it up and first they said they didn't hear a noise and then they said the noise was normal.

 

I took it to my indy mechanic and they agreed that the noise was abnormal, however didn't know exactly what it could be. They did change the fluid in the front differential but that hasn't seem to make any improvement. (they said the fluid was black, low and lots of shavings on the drain plug).

 

In researching this online I found a number of similar complaints and a few TSB documents which seem to apply. I have requested they replace the front propeller shaft even though they don't think it's neccesary.

 

Does anybody else have this whine noise from the front end (seems to be stronger from the driver's side). If so, how have you fixed it?

 

Is the propeller shaft the most like cause?

 

If the propeller shaft swap out does not resolve the noise what should I advise they try next? Front differential bearings?

[z0lt3c]

Well I got the car back from the dealer today and they claim to have swapped the front propeller shaft but it has made no difference to the whine. It it still present at the same speeds ... maybe it it slightly improved but not much.

 

The dealer still claims there is nothing wrong with the truck and has no additional recommendations for repairs. I'm going to try either another local dealer or a local indy.

 

I think the next step is to open up the differential and inspect the bearings and gears.

 

Any suggestions?

 

 

 

BTW: The dealer charged me $130 to flush the differential fluid in the rear differential after my indy flushed the front for $45. The bill shows they charged $23 per liter of oil ... this seems very high to me.

[Frank Sub]

Hi zOlt3c--I have a slight whine, of the type you describe, when the drive button is in automatic, and operating in 2 wheel drive. When the button is in 2 wheel drive the sound is not there.--Frank Sub