Front End Grinding/Scraping Noise

[reansor]

My 2003 AWD Mounty has a grinding/scraping sound from the drivers side front that is most pronounced on deceleration. Both front wheel bearings/hubs are almost new, as are the inner and outer tie rods and the ball joints all check out fine. Yesterday, as a test, I removed the front drive shaft and the noise vanished which leads me to believe that it's not the front axle bearings since the front differential on AWD is spinning whether the drive shaft is attached or not. The U-joint and CV joint on the drive shaft seem fine too. Maybe the transfer case? Even with the driveshaft removed, that is also spinning on AWD. The front U-joint did seem a little aged, but did not have any slop and does not clunk when I put it in gear.

Does anyone have any ideas? My last resort diagnostic is to put it up on 4 jackstands and let someone put it in drive while I go through it with a stethoscope.

Any advice or suggestions would be greatly appreciated!

 

[Number4]

The viscous coupler (for the AWD front diff) on these go bad, from what others post. I don't know what it does once it fails.

Careful putting it on 4 stand and firing it up. I tried this at one point. Shifted into gear and thought the thing was going to come off the stands

 

[estell]

The viscous coupler (for the AWD front diff) on these go bad, from what others post. I don't know what it does once it fails.

The viscous couplers do go bad. I replaced mine. The problem occurs when turning, not just decelerating. Vortex Garage has a diagnostic video for the viscous coupler. Check it at https://www.youtube.com/watch?v=UZrIBSB_6lA

 

[ShamgarBrett]

I'm having similar sound and beginning diagnosis. I've removed my front drive shaft and replaced the rear wheel bearings. Changed transmission and rear differential fluids so far. I expect if the viscous coupler was fried then the rest of my drivetrain is under increased stress. The rear tires both have irregular wear. Hope you found the source!

 

[abes.shop]

I know that this is an old thread, did anyone find out what the problem was? I am having a similar issue with my 98 Explorer 5.0 XLT AWD, the noise sounds like the squealing or grinding when the brake wear bar is constantly scraping the rotor like it is when the pads need to be replaced, front pads are good. I mainly hear it when I am slowing down with and without the brakes applied. My viscous coupler and u-joint are fairly new and both wheel hubs have been replaced, I am starting to wonder if it is the cv-axels or the differential gear bearings. It is driving me nuts any and all help would and will be greatly appreciated.

 

[Fix4Dirt]

I know that this is an old thread, did anyone find out what the problem was? I am having a similar issue with my 98 Explorer 5.0 XLT AWD, the noise sounds like the squealing or grinding when the brake wear bar is constantly scraping the rotor like it is when the pads need to be replaced, front pads are good. I mainly hear it when I am slowing down with and without the brakes applied. My viscous coupler and u-joint are fairly new and both wheel hubs have been replaced, I am starting to wonder if it is the cv-axels or the differential gear bearings. It is driving me nuts any and all help would and will be greatly appreciated.

this is 3rd gen forum hope ya get an answer thoigh!

 

[abes.shop]

this is 3rd gen forum hope ya get an answer thoigh!

So you are telling me that your 1998 XLT 4x4 4.0 v6 is a third generation and my 1998 XLT AWD 5.0 v8 is not?

 

[Fix4Dirt]

So you are telling me that your 1998 XLT 4x4 4.0 v6 is a third generation and my 1998 XLT AWD 5.0 v8 is not?

no wasnt sayin that, mine aint a gen3 either i just hang out here, and basically all the subforums was just lettin ya know just in case!

 

[LMHmedchem]

I know that this is an old thread, did anyone find out what the problem was? I am having a similar issue with my 98 Explorer 5.0 XLT AWD, the noise sounds like the squealing or grinding when the brake wear bar is constantly scraping the rotor like it is when the pads need to be replaced, front pads are good. I mainly hear it when I am slowing down with and without the brakes applied. My viscous coupler and u-joint are fairly new and both wheel hubs have been replaced, I am starting to wonder if it is the cv-axels or the differential gear bearings. It is driving me nuts any and all help would and will be greatly appreciated.

Does the sound sound like it is coming from one side more than the other?

I would do the easy stuff first.

I would take off the wheels one at a time and spin the hub with the caliper and rotor still installed. First look for the rotor scraping against a rusted/bent/broken dust shield or something in the brakes. Then place a screw driver against the wheel knuckle so that the tip is close to the inside of the rotor. Spin the wheel through a revolution and watch to make sure that the distance between the tip of the screwdriver and the rotor doesn't change. If you see the distance moving in and out then your rotor may be warped or the hub may be damaged. If that happens, take off the rotor and check it with a level.

If the rotor looks ok, take of the brake caliper and rotor and do the same thing with the screwdriver near the back of the hub to make sure that the hub is spinning straight. Even though the hubs are fairly new that doesn't mean that they have not developed a problem, especially if the replacement parts were low cost.

If all that looks ok, spin the hub while someone turns the wheel all the way right to left and see if the sound appears. Inspect the dust boots on the CV axle and look for signs that gear oil may be leaking from where the CV axle inserts into the differential. Also check to see if there is any play where the CV inserts into the differential. See if you can make it move up and down or front to back.

All of that can be done with minimal disassembly. If that doesn't reveal anything on either side then you may have to remove the CV axles so you can inspect the carrier bearings in the differential and also pull the boots back and inspect the internals of the CV axles. Removing the CV axles is more work since you will have to remove at least the axle nut and free the upper ball joint and outer tie rod end. This is often enough to get the axle out but you may also need to remove the sway bar link and lower ball joint nut. It's not awful to do but I would spray up all of the nuts with PB blaster several days in advance and make sure that you have all of the proper size sockets. The axle nut is pretty big.

LMHmedchem

 

[abes.shop]

no wasnt sayin that, mine aint a gen3 either i just hang out here, and basically all the subforums was just lettin ya know just in case!

Sorry about how I answered you I did think ours were 3rd gen not 2nd gen

 

[Fix4Dirt]

Sorry about how I answered you I did think ours were 3rd gen not 2nd gen

no worries yeah for 4doors 20-present is 6th gen 11-19(?) is 5th gen06-10 is 4th gen 02-05 was 3rd gen 95-01 is 2nd gen 90(or was it 91?)-94 is 1st gen

 

[abes.shop]

I know that this is an old thread, did anyone find out what the problem was? I am having a similar issue with my 98 Explorer 5.0 XLT AWD, the noise sounds like the squealing or grinding when the brake wear bar is constantly scraping the rotor like it is when the pads need to be replaced, front pads are good. I mainly hear it when I am slowing down with and without the brakes applied. My viscous coupler and u-joint are fairly new and both wheel hubs have been replaced, I am starting to wonder if it is the cv-axels or the differential gear bearings. It is driving me nuts any and all help would and will be greatly appreciated.

Thanks for all the input, it ended up being the front axle cv joint making the noise.