U-joint?
 

I've got a low "howling" when I'm driving, it's not my tires either, the Michelin LTX's are quiet. I wanna say U-joint but I don't have any vibrations...

Thoughts?

05 2dr 4x4 Manual trans.

Wheel bearings?

Does the noise change when you turn?

Nope, pretty well constant... For that reason I sort of ruled out a wheel bearing... I got my U-joint repalced but the mechanic installed some Junk "greaseable" joint. I'm unable to access said fitting.

I think I'll be buying a Delco U joint and going back to see him.

Is the sound coming from the front or back? A rear wheel bearing really won't have a change in tone when turning.

my wheel bearings made a similar noise and I replaced them and no more noise. try wiggling your wheels and see of they have some play in them

It's difficult to say. sometimes it seems like it's coming from the rear, and other times from the middle, like right under my arse... I have exams all next week but I think I'll go on the 26th to the garage and get them to check my bearings/U-joints. I never thought of the rear wheel bearings, the lack of vibration would make sense if it's a bearing starting to go.

Thanks.

Could be an out of balance driveshaft. If the person who replaced the u-joints didn't keep things in proper orientation, it can throw off the balance of the driveshaft. If left out of balance, it can take out the bushing in the tailshaft housing on the transfer case.

I just went through all of this on my dad's '04 K2500.

I know the driveshaft was re-installed properly, I was under the truck after the install, and recently to try and grease it and even now you can still see the yellow marks he drew on the driveshaft and the diff to mark how it was lined up.

I'll get everything you told me checked though when I have the opportunity.

Bump...
Today I noticed the sound was coming from up front, inside below the engine bay. I do remember the mechanic talking about a missing gasket on my front diff, the fill plug gasket to be precise... I'm worried it's my freakin diff that spat most of its oil out, I'm calling and booking an appointment to get that damn gasket replaced and the front CV's and everything checked out. Irritating because it got lost at my second to last oil change, I'm sure of it but I can't prove anything.

There should be an o-ring on the fill plug. Nothing that you could see with it installed.