I have a 06 Mega Cab 2500 CTD with 1200 miles on it.
Since day one it has had a very annoying howl, that appears between 70 and 75mph. It only happens when under a light acceleration or deceleration load.
Which means that if you are cruising on the highway, you hear it all the time.
It is loud enough, that it can be heard over the radio.
What does everyone think ?

 

A number of things. Pinion bearing, side carrier bearing, wheel bearing,etc. I would hope not, having only 1200 miles. That sucks. Go drop it off and let them deal with it.

 

Problem is- only some dealers will "deal with it". Some cannot hear it, or will tell you it is normal breakin, etc..B...S.....

 

Thats right, but this truck only has 1200 miles on it. He paid alot of money to have a nice truck that didnt make a howling noise. I think you can persuade them reguardless. If your dealer wont do it, take it to another.

You didnt buy a Geo Metro. You paid top dollar for a top of the line truck.

 

Mine only had 500 miles on it when I took it in, and they told me it had to "set up a gear pattern" ! At about 10000miles, and 4 trips to the local yocal, I finally took it to someone who cared, and they changed the ring and pinion, which fixed it. Some service departments seem to want to do the easy stuff only. (My $.02!)

 

Yes it is sad that some dealers try to tell you its " a normal condition for this type of rear end". So ask them to take you on a test drive in another new or used truck and listen for the "normal" sound. My ring and pinion was replaced 3000 miles ago and howls again. It is back at ANOTHER dealer for another ring and pinion as the first one tried to tell me it was normal this time, but it is worse now than it was. So I took it to another dealer and they are getting it done correctly this time(hopefully). Not every Dodge tech is capable of setting up gears properly, there are actually very few people that can do this CORRECTLY. It is more than a simple "nuts and bolts" in and out swap.

 

I will take it to the dealer and see what happens...
I will post my results.
Hopefully they get it fixed, because I do a lot of highway driving and the howl is real annoying.
With all the cardan joints, U-joints and carrier bearings, I don't expect it to have a smooth driveline.....but I would like it to be quiet.
I see a lot of posts regarding the replacement of driveline components. Does DC use cheap axle parts in their trucks ?
I had several fords, and never had to replace a U-joint or ring / pinion until well after 100k miles.

 

Have you checked the fluid level in the rear axle? There have been cases where the gear oil level was low on delivery from the factory and the dealer never caught it during pre-sale prep. I'm not saying that is the cause of your noise, but it doesn't hurt to check.