Extremely loud grinding noise! HELP! $50 reward

[k12k08]

Hi, I have a 1999 ford explorer. (2wd drive, 6 cylinders, limited) Always since I had the car I had a humming noise in the back around 60mph. Then I changed the rotors and wheel bearing and added to this noise slightly.

Recently my car has been making a huge loud grinding noise( happened randomly at night) at any speed when I only press on the gas, immediately stops when I let go. Then for some stupid reason I wanted to see if it made the noise in drive. So at a stop light, I pressed the brakes and reved it 3k rpms. Then I said hey no noise, let go of the brakes, car started moving when it was already reved up at 3k rpms and made a huge grinding noise at the instant when I let go of the brakes. Now the car is barely drive able making a huge grinding metallic noise upon acceleration. I had to get it towed. I went back to my house, checked the oil and it was good.

When I got home for another dumb reason ( you can already tell what kind of person I am) put the car into '2' instead of drive and slightly accelerated. Made a huge grinding noise and car was vibrating even after I applied the brakes, let go of the gas and put it in park. If I can recall correctly, sounded like a starter trying to start the car while its on but the noise was continuous and loud I also still hear the loud grinding noise. It stopped after I shut down the car.

I also want to note that grinding noise is extremely loud and can be heard on the side walk. Also, the car doesn't make any extra noise shifting gears or idling or when reeving the engine. Also before the terribly loud grinding noise happened, there was still a loud grinding noise. When I went down hill I let go of the gas and the noise also went away even though the car was moving around 40 mph so I dont think its the wheel assembly or bearing but I can be wrong.

Anyone have any clues, I dont want to pay a tow truck to a shop then tow it back home. If someone can tell me the exact problem it is, I will venmo or paypal 50 dollars. I want to see if it is worth fixing before I shell out money for diagnostics and more towing...

 

[acschilling]

Check the u-joints on your rear drive shafts.

 

[boominXplorer]

Sounds like a u joint or rear axle issue. Look at the bottom of the rear differential cover, is it wet with fluid? (look under your rear bumper and look right in the middle to find the cover, it has 10 bolts on it). Or is there fluid on either side of the backing plate behind the rear brake rotors?

If those pass with no fluid found then put some blocks around the tires so the truck can't move and put it in neutral. Then grab on the driveshaft and look for play.

If you still can't find anything pull the fill plug on the rear axle, its magnetic. There should be a slimy coat of metal on the plug. If you find any actual pieces bigger than 1mm you have an issue inside the rear axle.

 

[just1me]

Yupp agree with boomin, most likely a ujoint or the rear axle. I have heard a rear axle hum pretty loud but not to the point of grinding, but it could still be that.

 

[Bobmbx]

I vote for a bad pumpkin. The car would move even with a bad u-joint; grind the teeth off a rear end and you got nothin' going to the wheels.

 

[Gadget X]

Yeah, if the noise is in the rear, I vote for a bad differential. If it sounds more like it's coming from the engine compartment, I'd say that either your fan or a pulley is against something that it's "grinding" on. Good luck with it!

 

[beach]

Yeah doesn't sound like u-joints, your case it sounds like the rear diff has gone bye bye or is one its way out.

 

[k12k08]

Sounds like a u joint or rear axle issue. Look at the bottom of the rear differential cover, is it wet with fluid? (look under your rear bumper and look right in the middle to find the cover, it has 10 bolts on it). Or is there fluid on either side of the backing plate behind the rear brake rotors?

If those pass with no fluid found then put some blocks around the tires so the truck can't move and put it in neutral. Then grab on the driveshaft and look for play.

If you still can't find anything pull the fill plug on the rear axle, its magnetic. There should be a slimy coat of metal on the plug. If you find any actual pieces bigger than 1mm you have an issue inside the rear axle.

Yeah, the rear differential cover did have fluid on the cover when I looked at it yesterday. Its only wet on each side and not the middle.

 

[boominXplorer]

Yeah, the rear differential cover did have fluid on the cover when I looked at it yesterday. Its only wet on each side and not the middle.

It's probably coming from the pinion seal because the pinion bearing exploded. At this point a used rear axle is going to be your best bet for cheapest repair. You can check the tag on the rear axle cover bolt or the drivers door sticker for your gear ratio.

 

[the_don]

pinion bearing or differential support bearing. pinion bearing is easy enough to look for, block the tires put it in neutural grab the yolk see if it has any play up-down side to side and in and out. differential support bearing is a little harder, i would pull the cover see if anything is sitting on the bottom.

 

[4wheeltom]

Definitely sounds like a pinion bearing, symptoms are exactly the same as when the one in my moms Jeep went out

 

[acschilling]

So....

 

[ThatExplorerDude]

On my explorer it would grind as soon as I put it into gear. Turns out my shift motor for my t-case had stopped working.. and It was grinding inside the transfer case... stuck between 4hi and 4 lo making a God awful racket and vibrating lots of noise.. even on start up on the truck

To test if its that... just take off the shift motor... see if the trangle piece that selects your t-case setting is setting halfway between markings... if not make sure it is rotated fully into any of the slots... As soon as I fixed that.. absolutely no grinding noises..

Hope that helps