I have a new style '04 (4.6l) F-150 with ~260K. I have been changing the trans fluid (automatic) every 80K (100K recommended). It's been a good runner, but I'm starting to hear a noise and am trying to figure out what it is. The transmission seems strong- no slipping or shifting issues. No odd sounds with the windows closed (sounds perfect) but when I drive with the window open, I can definately hear something- I'm thinking it's the torque convertor.

Anyway, I hear a noise when I am accelerating, the harder the acceleration, the louder/faster the noise becomes. I would describe the noise is kind of a metal scraping sound, It's hard to describe, but it reminds me of the sound an electric clutch makes when you turn it off and it brakes to a stop. What it really reminds me of is when I turn the electric clutch by hand when the motor is off.

I took it out for a drive tonight to try to dial it in. If I'm stopped with the brake on and step on the gas (even hard) it sounds normal- no scraping. There is also no scraping when I take off from a dead stop. I have to get above maybe 10mph before hearing anything odd. Once above 10, the scraping becomes audible. If I accelerate lightly, the noise isn't there, or hardly audible, but if I step into it a bit the scraping is definitely there. It's not a constant sound, more of a scrape, scrape,scrape and it is definitely related to rpms. If I let off the gas the noise goes away.

Again I can only hear it with the window open, but it's loud enough to bother me. I'm due for another fluid change, but the fluid looks and smells good. It's a tad low, but on the dip stick. I'm wondering what I'd find on the magnet if I dropped the pan... Any thoughts?

good luck -jim