08 Explorer front end grinding

[blkmonday]

I have an 08 explorer 4x4 with 90k. I have a front end grinding noise. Noise is loudest at lower speeds and doesn't change with braking or turning. I have read that tires could cause this. I have the spare tire and rim on the front at the moment until I can afford a new tire. My other tires are all pretty new... And the spare is a different size rim but a brand new different brand tire. Can it be my tires? Bearings? Worse? I'm going to check for play in the bearings tonight and maybe swap the spare to the rear and see if that helps. Suggestions?

[shorod]

Does the noise change with vehicle speed?

Is there any difference in the noise if you shift in to neutral?

Did this noise start after you installed the spare tire on the front?

You mention that it's a different size wheel. What is the tire size on the spare and what is the tire size of the other 3 wheels?

If your Explorer has an option for 2WD, try that mode and see if it changes. Also try locking in 4WD to see if that makes things better or worse.

Making sure the lugnuts are tight and there is not play in the bearings will be good things to check. Let us know the results. I also like your plan to swap the spare to the rear to see if that changes anything.

-Rod

[blkmonday]

I'm at work right now but just realized the spare is a 245 and the others are 235's that could be my problem. I'm going to put my plugged tire back on and order. New tire in the meantime. I didn't drive all that much on the spare. Do you think I damaged the differential or transfer case when I used 4 wheel yesterday (prob 5 miles)? I'm going to put the new tire on and if it still makes noise pray my warranty covers the rest

[blkmonday]

ok i swapped the tires and the noise is gone in 4x4 auto. however its still there in 4x4 high. noise seems louder at lower speed, bearings seemed fine and the sound doesnt change when turning or leaning into one side or another (kind of rules out bearings). can it be a front u-joint? if so how hard is it to change? i didnt check the fluid level in the transfer case yet. i took a quick look at the front end, no rips in cv joint boots or any signs of leaking. also this seemed to start after i changed that tire to the spare. i bought the truck in the spring though and havent really used 4 wheel drive until this week other than making sure it engages back when i test drove it. i did order the other 2 new tires (general grabbers) and they will be installed on thursday. could the bald tire i put back on be so much smaller than the other "decent" tire that it would do this? i guess ill know that answer thursday when all tires match

[shorod]

If you're driving in 4x4 High on a non-slippery surface, it could just be that. You're not supposed to drive in 4x4 High if you are on dry or wet pavement, only snow, ice, sand, or gravel. Since the noise is not present in 4WD Auto the issue may be the terrain you are engaging the 4WD in.

The first number of the tire size is the width, the next number is the aspect ratio (percentage of the width that the sidewall is tall) so it's possible to have a wider tire that is essentially the same overall height/circumference. But if the noise was present with the spare installed in 4WD auto, I'm betting the tire size is different enough that the 4WD system detected slip and attempted to engage the 4WD.

-Rod