I could swear I hear a faint sound of what sounds like metal dragging when accelerating hard. I thought I noticed it when I was doing about 60 today. Transmission isn't slipping, and I think (it's faint) it happened even when I took it out of gear and hit the gas while I was free rolling. I stopped though and revved the engine while sitting still, and nothing.

Transmission, differential, and engine oil levels are all good. No metal shavings in the tailpipe so it's not the catalytic converter, and even revving the engine to 5,000 RPMs while stationary I don't hear it. I just replaced the fluid and gasket on the rear differential about a month ago and there was no damage to any of the gears in there so it's not the rear end. I do have a U-joint that pops a little when changing directions, but I haven't had any other issues with it, and the pop that it does make every now and then hasn't worsened, and there's no vibration, so I don't think it's a U-joint. I didn't hear it all the time, just here and there, so I'm thinking it may have just been some of the stiff winds we had today whistling across the empty pop cans in the back, but I'm usually pretty good about picking up on when something is different with our vehicles and am wondering what could make that sound. It literally sounded like something was hanging loose and being drug along the highway, but nothing that I could find was hanging, and it wasn't a very loud noise either.

 

check your torque convertor bolts and any shields down there.

 

5 speed manual transmission. I took it out of gear and let it free roll and still thought I heard it when I slapped the gas in neutral, but when I stopped and hit the gas, nothing. Held the RPMs at 5k for about 20 seconds, no sound.

 

I'd look at the heat shields, could easily be air moving them around. If it's faint, IMO don't worry about it till it gets louder.

 

We did have some stiff cross-breezes today, and some empty pop cans in the back along with other misc. items, and I don't even hear it all the time.

I think maybe I'm just going crazy, :P

 

Put it on stands all around then run it in drive. Also neutral and spin wheels by hand. Might be brake shoes lightly dragging.

 

I had a strange noise that sounded like I was dragging a small chain behind the truck for years turned out to be one of my hubs.

Drove me crazy trying to figure it out you could hear it the loudest on off ramps echoing off the concert wall back at me.

One Hub finally started making a grinding noise changed it and SUPRISE no more sound of dragging chains.