Vibration When Letting Off Accelerator Slowly

[felixexplorer]

I purchased a 4x4 '03 Explorer. On the way home from the dealer with the cruise set, I noticed that when going down even the slightest decline and the accelerator slowly decreased there was a vibration coming from the rear of the vehicle. So testing to see if it was a cruise problem or something else I turned the cruise off. Going down hills both big or small when letting off the accelerator slowly I would get the vibration. Still testing the issue, when letting off the accelerator more quickly it was less likely to do it or at the very least not as bad. It seemed to only do it when the acceleration release was very easy and slow. Any ideas???

 

[Curtis]

Sounds like your rear differential
Its a common problem in the early 3rd generation Explorers.
My dads 02 does the same thing. If you keep your foot on the gas just a little bit it doesn't do it. I believe its when the gears in the rear diff are worn, and hum because of coasting.

I think its usually a $1500+ rebuild job. Some have been lucky to have Ford cover it under warranty.
But its more of an annoyance, you shouldn't be doing any damage. Its just normal wear.

Im sure someone else will add more to this.
If you search for "rear whine" you will find alot of information

 

[RossA81]

Just picked up a '04 4.0 4x4 it has the exact same issues you describe. I only notice it if I am at highway speed and let off the gas and coast. I'm going to just ignore it unless I notice it getting worse.

Ross