In my 2004 fx4, there is a whining noise in the rearend when power is applied. Seems like it is on the drivers side but not sure. When coasting the rearend is quiet. Replaced the carrier bearing but noise is still there. Is this a common problem.

Thanks
Duane

 

When I'm offroading in my 04 lariat 4x4 and im spinning my back wheels in 2wd, I'll hear a whining noise also. Don't know what it is though sorry I'm not much of a help

 

whining on accel or decel is the pinion bearrings.

 

Thanks papajohn. During decel the rearend is quiet. But i think it is the pinion too. The whining sound has not gotten any worse over the last 3000 miles. I think i will leave alone until the sounds starts to get louder.

 

I had the same issue on my 130K mile '94 Lightning. I added a bottle of Lucas Oil Stabilizer, 4 oz. Ford FM and topped it off with Ford 75W140 gear oil and it is a lot quieter now.

 

The 2000f150Scab4x4XLT developed a very minor whine at around 60k. Still good at 150k. My current 2002 has a very minor whine. It had 69k miles when I bought it and now has 93k and has not gotten any worse. I've rented new cars (Grand Cherokee comes to mind) that had a minor whine in the rear.

 

I had the bearings and seals replaced 2 weeks ago because of a whining noise in rearend. i have a 2005 FX4 w/ 72,xxx miles on it.

 

I just got my truck back from the shop fixing that same problem under warranty. It ended up being the pinion gear in my rear end. replaced that, and the metal ring it spins on, and bam, no more sound! Took them long enough to do it!