03FX4604

So for the past few weeks I've had a whine coning from the rear of my truck, it's directly related to wheel speed, you speed up it gets faster and louder, and vice versa. There's no popping or creaking. I replaced my diff fluid about 10k ago with 75w-140 and friction modifier.

There's a whole list of things I thought it could be. Ujoints? Pinion bearing? Axle bearings?

Any thoughts?

Dholla

Could be a rear differential leak. Mine made a slight whining noise in the rear that sounded like a plane landing haha best way to describe it but it ended up being a rear diff leak

03FX4604

Was it your pinion seal?

03FX4604

Bump

99Longhorn

My old truck dud that and I was told it needed to be rebuilt. The gears get worn and don't go together 100%

Cal3bCart3r

mine has been doing it for just about a year now ....i haven't changed my rear diff. fluid in 2 years so i think a bearing or my whole rear end is going out ....i was kinda expecting it tho since in my early teen years i gave her hell in the mud :/ i wish i would have listened to my parents (i have a 2002)

AlbertoA

Mine did that, shortly after a fluid swap. No "cause" really. Just got unlucky and had a piece swim around in there until it found its way between the pinion bearing and race. I noticed the noise about 40km into a 700 km round trip. So when I got home and I opened it up everything was blued from going red hot. The race was rougher than sandpaper and the bearing rollers too.

Simply changed the race, bearing, seal and flushed the fluid. It howls a little when coasting at highways speeds. But I have a lot of mileage on it. I didn't replace everything I could have but it cost me $200 (mostly fluid) and 3 hrs as I'm no pro gear head.

7700SCREW

for anyone that has a worn rear diff that wines and doesn't want to rebuild.
Change your diff fluid out and replace it with Lucas oil stabilizer.
I did this on an old dodge years ago because the diff Howled very bad and it quieted it down to almost how it should be and lasted for 2 years until I sold it.
The kid is still driving it all these years later.

Dholla

The seal was bad and they had to re weld the differential as well. Then the problem went away

finalwest

I replaced the fluid in my excursion and experienced the same thing (AMSOIL). I had both my carrier bearings and the pinion bearing replaced.. Its hard to tell what it could be until you take everything off though. Jack the truck up and see if there is any play on your tires ( Jerk the wheel in and out) If both of them are are solid then its going to be on the inside. I wish i could tell you how long they will last before they go out but i replaced mine the same week i heard the noise,( I was about to tow a 13k pound trailer 1800 miles), So hopefully yours stays intact for a while.