Whirring Noise

[lkrasner]

2002 tahoe 4X4, 5.3L flex fuel, 280,000 Miles

I have a whirring sound that is very similar to that of most cars when driving in reverse. It gains pitch with vehicle speed, regardless of gear or RPM, and persists if I shift into neutral. I'd like to say it's coming from the front end, but it's hard to tell honestly.

Had wheels perfectly balanced with no change.


a few thoughts so far: bad cv joint on the front axle, bad intermediate steering shaft, unbalanced driveshaft. Any of those make sense. how should I go about checking.

Only other interesting detail is that this seemed to start after I had an oil change place do a "rear differential service" I believe they just drained the fluid through the plug and refilled it. could they have somehow overfilled it or something to cause the issue? I'm affraid to actually pull the cover given all the rust. If I break anything and can't get it resealed I'm totally screwed.. Should I just drain from the plug and refill it?

 

[t_ahan]

not sure if this helps but with my 03 denali (awd), there is a GM additive that is required to be used when filling the diffs...also check your bearings, with bad wheel bearings sometimes you can get the noise to change pitch by swaying the vehicle slightly to the right and left while driving (loads then unload the bearings)

with the help/support from the forum you should be able to diagnose it

hope you get it figured out soon

 

[lkrasner]

Front bearings are brand new, rears seem to be good.

 

[SLCHOE]

2002 tahoe 4X4, 5.3L flex fuel, 280,000 Miles

I have a whirring sound that is very similar to that of most cars when driving in reverse. It gains pitch with vehicle speed, regardless of gear or RPM, and persists if I shift into neutral. I'd like to say it's coming from the front end, but it's hard to tell honestly.

Had wheels perfectly balanced with no change.


a few thoughts so far: bad cv joint on the front axle, bad intermediate steering shaft, unbalanced driveshaft. Any of those make sense. how should I go about checking.

Only other interesting detail is that this seemed to start after I had an oil change place do a "rear differential service" I believe they just drained the fluid through the plug and refilled it. could they have somehow overfilled it or something to cause the issue? I'm affraid to actually pull the cover given all the rust. If I break anything and can't get it resealed I'm totally screwed.. Should I just drain from the plug and refill it?

not sure if this helps but with my 03 denali (awd), there is a GM additive that is required to be used when filling the diffs...also check your bearings, with bad wheel bearings sometimes you can get the noise to change pitch by swaying the vehicle slightly to the right and left while driving (loads then unload the bearings)

with the help/support from the forum you should be able to diagnose it

hope you get it figured out soon

Take it back and tell them the issue. They may have used the wrong fluid that does not have the additive package in it.

 

[lkrasner]

Take it back and tell them the issue. They may have used the wrong fluid that does not have the additive package in it.

They definitely did. I remember the conversation. One guy was under the car and yelled up something along the lines of "is this one of the ones that needs the limited slip additive?" someone else looked it up and told him "yes". I may still bring it back, but it almost certainly has the right fluid.

 

[rob76]

I would put it all up on jackstands and see where the sound is coming from. Gotta be careful though, for obvious reasons. Don't get underneath or in line with the vehicle if it fell off the stands and drove over you.