I have a 02 4x4 with the 5.9L.
i have a whining noise coming from the rear diff and now a low to moderate vibration. I replaced the wheel bearings today. I originally blamed it on the pinion gear but found its not the pinion. ive inspected the gears everything looks fine in the carrier. by the way the only time i hear noise or feel the vibration is when im on the gas. im gonna tear my rear end apart again tomorrow, any ideas or previous experience with this problem?

 

before you tear into your rear double check your U joints. I had the same issue and i replaced the pinion bearing and checked the preload multiple times before i realized my U joint was bad.

 

it sounds like a u joint issue

 

replaced u joints while i had it apart and the old ones were in great shape,

 

I had a friend change out my pinion seal and he overtightened the pinion nut. Now I have a whine when I get on the gas. Even a slight increase in the gas pedal will cause the whine. The overtightening on the nut messed with the crush sleeve. I will be getting new gears soon. I have driven over 6,000 miles since he did it but i am sure it will blow up if I don't do the new gears. Plus it's the POS LSD so I have been lucky to get 101,000 miles out of it.

PS, I do not have a vibration though.

 

I have the exact same issues out of my 97 4x4. Please let me know if you get this puzzle solved before I do. Im thinking u-joints or rearend bearings. Any info greatly appreciated.

 

When you checked the pinion, did you remove it and also checked the bearing and did you do it by the "counting the turns" to remove the pinion nut method?
Did you managed to screw the count up and overtighten the pinion nut back up, causing damage to the old crush sleeve?
That would give you noise as the pinion depth isn't now set correctly.
Just a thought.
Al.

 

vibration is usually and indicator of something loose. U joints or pinion bearing would be my guess.

 

well i took the opportunity of having it apart to install my new 4.56 set, and replaced my trac-loc clutches. it was the driver side carrier bearing making the noise and vibration was caused by the u-joint i bought, it literally had not pins in one of the caps,,,,,while i was in like i said new gears, new carrier bearings, wheel bearings, trac-loc clutches, pinion bearing and seal,,,,the only thing i diddnt replace was the spider cluster, diff kit at advance auto was 140, and it drives like new, and of course getting an extra 3mpg with new gears, thanks for all the help guys, and if you have dif problems let me know, ive probably already experienced it and fixed it

 

What was the final cost on the gear swap and what exactly did you replace? Just getting ready to have mine done. Thanks.