Drivetrain/Rear end grinding noise

[Keith Weagle]

Hi Guys,

I have a 2007 Silverado (new style) with a noise that appears to be coming from the rear end. It is most noticeable at lower speeds and only while coasting or slowing down. While accelerating the noise seems to disappear. The best way I can describe it is an intermittent grinding noise, similar to the sound of a bad wheel bearing or u Joint.

U joints have been checked and are fine. Rear end was opened today and there was some wear on the Pinion Shaft retaining bolt. The mechanic replaced the bolt but not the shaft. The noise is still there and seems to be as loud as it was. I have been told that axle bearings never go in these trucks?

It is hard to tell but the noise seems related to the speed of the drivetrain rotation rather than the actual wheel rotation, so I am guessing it is an issue between the transfer case and rear axle.

 

Any ideas as to what this may be?

[Keith Weagle]

Well, I found the problem.... I went for a drive with my drivers side mirror pointed down watching the tire to see if I could tell if the noise was 1:1 with the tire rotation or not. I noticed a slight wobble in the tire which was odd. No more than 15 seconds later I watch one of my wheel nuts sheer off and go flying. Pulled over and four of them where ready to fall off. I had some new tires installed last week, and it looks like that tire may not have gotten torqued down. Re Torqued everything and the noise is gone.

I have taken my truck to the same garage since new and have had the tires changed twice a year (seasonals) and never had a problem before. I guess I got lucky that I decided not to take the truck on the highway today!

[00Silverado4x4]

Glad you were able to find/fix the problem before it became a catastrophic failure.