2007 Expedition EL 4x2, 110K miles. I get an intermittent grinding/rubbing sound and vibration on the driver's side. Almost sounds like tires rubbing on the wheel well, but more metallic and changes tone and pitch. More noticeable when accelerating. It'll make the nosie for a few seconds, then nothing for a minute or two, then the noise again. Any ideas?

 

What is the condition of the brake pads? If they're worn the pad wear indicator could be touching the rotor.

 

Wheel bearing ?

 

**Update** This afternoon, when the noise started again, the front end dipped a little like the brakes were lightly engaged. I jacked it up, pulled the wheel off and checked the brake caliper and stone guard. While it was on the rack, I grabbed all 4 tires at 12 and 6 and there's no play in the wheel bearings. I shook the driveline and there's no play in the hanger bearing. I made sure the skid plate wasn't rattling. I'm at a loss...

 

**Another update** I've just been up and down the same stretch of road for an hour, and here's the latest. It does it mostly at 40 - 45mph, 1200rpm. When the noise starts, the RPMs jump just a hair...like from 1200 to 1350. I can't get it to do it when the cruise is on, only when I'm controlling the gas pedal. As soon as I take my foot off the gas, the noise stops. I called 2 Ford dealers today and the service people I spoke to had never heard of anything like it.

 

**Final Update** Went to a transmission shop. Diagnosed as a slipping torque converter. The chatter sound was distinct. The shop owner knew the sound just by description, then confirmed it when he and I took a ride in the truck. He recommend a flush and fill with a filter change...said it's a 50/50 chance it'll fix it. If not, I'm looking at a $3K tranny rebuild. Ugh...

 

When was the tranny fluid last changed?

 

Hmm, why would it only make the sound on the driver's side?