hydrodriver

52K miles on my 07 6.0L 6 speed with 3.73 limited slip rear, disc brakes. Somewhere in the rear I have an rpm related "Whirr" noise, not very loud. Is not constant, sounds more like "Whirr - Whirr- Whirr, and gets faster with additional speed and rpm. I think it might be a bearing? Fluid level is good, already changed driveshaft universals. Of course my warranty is gone - 5 years or 100,000 whichever comes first. Have a big trip coming up in April towing 8,000 lb. 5th wheel, so want to put it to bed before then. Any ideas or suggestions? Thanks!

kc15

What speed does this occur. I have a 06 2500 with a vibration at 55mph. I can not find it. You can put your truck on jack stands and run it. Watch driveshaft to see if there is any wobble. I take my driveshaft out and no vibration. My rear differential looks new.

hydrodriver

That is on the list of things to do - just waiting for the weather to get better - 22 degrees this AM and snow (again). Also have a friend of my son that is a Ford Master Tech and he is going to come over and take a ride. I'll let you know what we find - probably next week.

Chevrolet Customer Service

Looking forward to your update, hydrodriver! We hope everything is resolved by the time you take your trip in April. While we understand that once a vehicle is out of warranty visiting the dealership for vehicle concerns may not be an option, please keep us posted if you do decide to go in as we're available to assist in that process.

Sarah (Assisting Louis), Chevrolet Customer Service

hydrodriver

Let me tell you about my experiences with our local Chevrolet service - at 26,000 miles I had a front wheel bearing go bad, I discovered it by taking the brake rotor caliper off the rotor and spinning the wheel - you could feel the bearing friction. Put the truck back together, took it to Chev dealer, told the service girl what I had done and found. Later in the day they call me and tell me it's my brakes! I came unglued, went and got my truck, took it home and took the front hub off, took it back and told the service girl she had about 30 seconds to get some authorization for two new front hubs, and give me my $75 back for a missed diagnosis. They consented and fixd the truck.
Then I had a rear brake caliper freeze (4 wheel discs on this truck). I found that because I noticed a funny brake pull when I used the brakes - took the truck out there again, they said I needed new shocks!, Again I took the truck home, took the back rotor off, and showed them the rust on the inside of the rotor where the caliper wasn't doing anything - yes they fixed it.
By the way, I barely got two years out of those cheap *** OEM shocks! If I could afford it, this truck would go down the road and I'd go try a Ford. Especially with this bull **** with GM moving more and more stuff to China after we the American taxpayers bailed them out and they have yet to pay anything back.
I'll fix this truck myself, thank you.

hydrodriver

Got extremely busy today diagnosing the truck - jacked it up, spun it to 90 mph, rode the brakes, there isn't any noise in the rear end with the truck jacked up. Also greased my replacement universals.
Went back to the front, pulled the hub off one side (2WD truck), turned it by hand, turned hard but smooth.
Over on a Dodge site, they discuss greasing non greasable front hubs via the ABS sensor hole. There is a website Courtsara that even modifies hubs so they can be greased. On the Courtsara TIPS at the bottom of their home page, they grease a Chev hub via the ABS sensor hole. I figured I have nothing to lose, so I did as their photos show, using the Kendall L-427 grease also. Did both hubs - guess what - my noise is gone. These non greasable front hubs must be just about dry when they are installed at the factory - there is no such thing is this world as "lubed for life".
I'll report back after I drive around for a couple weeks and see if my noises return -.

greaser1

I posted the way to pack your sealed wheel bearings. Sounds like you followed my instructions to the tee. I have read on other forums where people comment on messing with the abs sensor. The sensor is Holographic and reads off the reluctor ring inside the hub. In other words its magnetic pulses. Doesnt matter if its air or grease or what have you, it wont hurt the sensor. Glad you found my site to be informative. I will be adding more tips in the future. Being as you havent replied in a few months I assume you truck is still rolling.

tech2

how much grease did you put in the abs cavity? Do you fill it right up?

greaser1

What are you doing it in? What kind and size truck? You can see pics and explainations on Courtsara.com.