2008 LTD V8 drive train noise/whine during coast

[pjw73nh]

Greetings,

2008 Explorer Ltd V8 just under 100k Miles.

I am hearing a noise coming from the drive train. Does not appear to be transmission related as I can duplicate it in neutral. It is a whine/slight grind when (almost) coasting at slow speeds.

Usually under 30 and can be as low as 5, not accelerating, and not decelerating, but just in the middle (coast) with a very VERY slight increase of engine RPMs I get the sound. Even in neutral. I might even call it a "resonance".

If I increase decel or accel off that "sweet spot", it's gone. Might be coming from the front but hard to tell. Turning does not seem to have an effect on the noise. I can get it to happen in D,3,2 and 1. It's getting more frequent week by week. Otherwise the vehicle drives perfectly normal . No other noises or performance issues.

Thoughts?

Tnx..

 

[pzy3339]

I am dealing with a similar issue right now. Mild front end hum started shortly after I got the truck with 124,000 miles on it. As of today it has 156,000 on it. Now I have a loud hum at freeway speed and vibration between 0-10 mph. Feels like driving over small rumble strips.

You have hubs with integral bearings up front. Hubs with a pressed on bearing in the rear. Front differential, rear differential, front driveshaft, rear driveshaft, transfer case, and transmission.

If your hubs are original that's a good place to start. Motorcraft hubs are $168 on rockatuo, or $161 for Timken.

 

[pjw73nh]

Thanks for the reply.. Definitely not a wheel bearing issue. Usually wheel bearing noises are load related. Within the last 10k miles I did the front ones (both) even though only one was bad (I just didn't get the correct one the first time) the noise was VERY elusive in this car.

I am leaning towards thinking my current noise has something to do with differential/pinion bearing/backlash adjustment. But still not taking any action until I can determine definitively the cause.