Metallic grinding sound at exactly 25 mph, any ideas?
 

i've got a grinding sound coming from underneath the truck at exactly 25 mph. the grinding occurs both during acceleration, during breaking and at a constant speed of 25, the sound itself pulses somewhat, like pressure is changing on whatever is grinding. i can't hear it inside the cab when the windows are up, but when they're down i can easily hear it over my exhaust. this only occurs at 25, and it doesn't sound like it happens at the same speed as the drive line would be turning. Does anyone have any idea what this might be? i'm starting to think it's a transmission thing, initially i thought it was a front differential problem.

Possible u-joint failure? I'd get under and do a visual.
To check the u-joints, i'd chock the wheels, apply the e-brake and put the transmission in nuetral. Grab the driveshaft and see if there is any play, there should be none.
Driveline is usually vibrational and has a fade in/out sound.
Make sure you chock the wheels, don't need the truck running over you.

*take this as a guidline and perform at your own risk...lol

by the sounds of it you might need some new wheel bearings. to check that just jack up your truck take the tire off and wiggle the hubs up and down there shouldn't be any play in them at all.your probably gonna have to take the brakes and rotors off too.

your bearing can go bad even if its not comming apart. Just jack it up and spin each wheel and listen for a noise. it could be a backing plate (the shield behind your rotors. could be a ujoint like dog said

have u had any work done to it recently? brakes etc

i put new brakes on the front this winter (november maybe?), this grinding sound started before that but it was hardly noticeable. i'll go take a look at the truck again tomorrow, right now i'm waiting to get my hearing back in my right ear. shot 4 rounds from my buddy's .40 cal pistol today and forgot to put ear plugs in, now i can't hear on my right side at all, oops.

If it is pulsing, I would guess U joint first or rear wheel bearing. It you have a pinion leak than you have your answer. Good luck.

I was about to ask the same thing with this issue... Under hard acceleration I start to hear like a grinding clicking sound come from under the truck and can't decipher what it is? For example I take off from a stop sign and accelerate hard and I start to here a loud click don't know what this could be so any help would be much appreciated. Sorry MontanaRam not trying to take over your Thread.

no prob man, similar threads should always be linked.

i haven't gone out and checked it yet, just been feeling lazy this weekend, i'll check it out tomorrow for sure. i did jack up the truck and spun the front left wheel. it's not "smooth" while it spins, it feels kinda gritty, does this sound like a bad bearing?

Well may want to recheck your brakes as well, did you replace the rotors or just the pads? If the rotors are warped and you got a piston in one of the calipers sticking that could be another cause... Just throwin out ideas

i had warped rotors but i replaced everything last october or november, new rotors and pads. i'll jack up the truck in about 2 hours, still a little cool out to be laying on asphalt in the wind.