I've done a search but couldn't find any threads related to my problem. Everything posted about rear howl is happening at highway speeds (40-60 MPH, 60-100 KPH in Canada). The howl I'm hearing is at low speed, less then 10 MPH (20 KPH). It only appears when making turns, the tighter the turn the louder it is. I hear it the most when I'm , say, steering through a parking lot. It's only been making this howl for a few months, but it gets my attention more and more each day.

The clutch pack was replaced last year to fix a shudder on turns from a stop, and has been quiet up to about four months ago. Advice?

 

If it's at low speeds, something is seriously thrashed if it is coming from the axle. Axle bearings and/or axles, pinion bearings maybe. Get it rolling down the road to where you hear it, and pitch the truck left and right a little, see if the noise transfers from side to side any. This usually indicates a worn carrier bearing, 'cause the carrier is shifting slightly side to side as the truck moves.

 

Are you sure it could be that serious? It's most noticeable when turning right and moving very slow. I'm wondering if the tech that replaced the clutch pack put in enough lube, or the right lube for that matter.

 

I had this in my 04 viba lemon before Ford replaced it. I had a howl at low speeds when I touched the gas. Let off the gas and it would go away. A replacement rear end fixed it.

Nevermind all the other problems I had!

 

Didn't pay attention to where you said it happens mostly on turns. It could be something in the limited slip clutches. Is it any worse if the axle is cold, like first thing in the morning?

 

No. It makes more noise after I've been driving for awhile.

 

Hm, the limited slip clutches is the only thing I can think of that'd really get worse the more you drive. A bad bearing is bad all the time.

 

I'm thinking the tech overlooked the friction modifier when he replaced the clutch pack. I'll get it checked out when it goes in for it's next service in a couple days. Thanks for your help Quintin.