I have a 2008 Dodge Ram 1500 Reg. cab 2wd and when i drive above 20 mph i can hear a whine or roar from the rear end and it doesnt matter if im accelerating, decelerating. the noise gets higher pitch the faster i go. just wondering if someone could give me some insight as to what this could be.

 

What kinda mileage you got on it? Is it past the 30k mile recommended fluid change interval? Might be time to pop the pumpkin and look. Could also be the pinion seal is bad...

 

its got 72k on it. i just got the truck from the dealership last saturday. i was going to change the fluid in it anyways since i dont know the last time it was serviced. but a seal could be making noise like that if it was bad? i thought they just leaked when they go bad. I am going to pop the cover on sunday to see whats going on but im just wanting to get some insight before i do it so i dont have to open it more than i have to.

 

A seal means leaked fluid, leaked fluid means low or no lubrication, which in turn means metal on metal which equals a whine if it's associated with an axle or differential or hub for that matter.

Look at the pinion seal and change the diff fluid (it's probably way past due anyway). Take note of any metal that may be stuck on the magnet as this may tip you off...

 

ok ill change the diff fluid on sunday and see where that goes if everything checks out with the diff ie. no metal on magnet and seal looks fine is there anything else i should look at?

 

Could also be tires or a u-joint going bad

 

So what's the verdict? If the diff checks out okay, I second the motion of a bad u joint.

 

Sorry i couldnt get to it sunday the wind was blowing about 40 mph and i dont have a garage. Oil doesnt drain to well when the wind is blowing. Im very good at making messes lol. hopefully i can get it done this weekend.

 

Bad u-joint is the first thing that comes to mind. You can try and shake/turn the driveshaft and if theres any movement between the ujoint and driveshaft then the ujoint needs to be replaced.