me and my dad were driving home on the freeway one day and we noticed that there was a odd noise coming from the back of the truck when we backed off on the gas. it didnt seem to make any noise on the streets just on the freeway. it has been parked for at least a year, but started every other week. im guessing its coming from the rear differental. any ideas whats up with my truck?

 

What kind of noise? A whine? A grind? A chirp? What? Need to know that

 

If it's a growl or hiss you hit a coon ha ha [sm=happybounce.gif]

 

it a whining noise

 

low fluid levels is what it sounds like to me, but let some guys that are more knowledgeable chime in... my 2 cents

btw i could be very wrong lol

 

if its a whinning noise its definately my girlfriend.

i hear a whinning noise coming from my rear too. i thought it was my rear wheel bearings. i replaced them and i was wrong. i also replaced my u-joints, another possible culprit. wrong again. all i have left is my front passenger side u-joint or my pinion bearing. i know that passenger ujoint is bad but im not sure if its making the noise. i only hear it at higher speeds too. im hoping that the noise just sounds like its coming from the rear because im moving fast.

 

anyone else wanna put in their opinion?

 

If it's a whine or a growl consistent with road speed (as opposed to engine speed) chances are your rear differential fluid could be losing it's lubricity. Differentials should be serviced annually,at the very least, especially if they are frequently put under load. They generate a suprisingly high amount of heat, which will cause the gear oil to break down and lose its lubricating properties over time. Just remember to get the limited-slip additive if you do get your rear diff fluid changed. Should only run you about $25 - $30 at the minit-lube.

 

thanks for all the advice

 

I whine or moan can be bad bearings too.