Grinding/Rubbing Sound - Help

[nc3310]

Hello everyone!

Here's the deal...bought a 2001 XLT AWD 4.6L (68,000 miles) several weeks ago. I'm experiencing a low pitched grinding/rubbing sound about 5% of the time, during exceleration. It's been extremely random and hard to pin point. My guess was that the AWD system was kicking in for some reason. So, today I pulled fuse 104 and disabled the AWD system (thanks to this forum for that info). After a long test drive, it seems the condition is gone. So what's my problem???? One idea i have is the tires. The two rear tires are brand new Goodyear Wrangler 265/17. The two front tires are wore out Goodyear Wrangler STs of the same size. Could the difference is the tire circumference be enough for the truck to be kicking into four wheel drive randomly???

 

[Froggy Ford]

Hey there, so was this sound coming from the front or rear of the expy? Also have you looked at the half-shafts in the front for torn rubber boot/s also might have a front wheel bearing going bad. And did you experience it at all while turning?

 

[nc3310]

The sound seems to be coming from either the middle or the front of the vehicle. I don't recall specifically looking at the half shafts but everything looked good the last time I had it up on the lift. The only thing needing attention are the ball joints. I don't think I have ever heard the noise while turning it always seems to be while going in a straight line. Like I posted earlier I pulled the fuse last night disabling the all-wheel-drive system and everything seems to be working great haven't heard the sounds since. I'll leave it like that until I get it figured out.