1998 Explorer 4x4 Hump Hump Noise

[dc goddard]

Replaced both 1/2 shafts. Replaced both outer bearing hubs to fix noisy front end. Made double sure of my torque specs. No change. Still have that hump, hump noise coming to a stop. Noise will diminish at high way speeds. But always present. 50 MPH is when it's most noticeable. Removed front drive shaft, noise still there but not as noticeable. Front diff. looks fine with a little play at rest. Will move back and forth, clockwise, counter clockwise, but no up and down movement. Transfer case has a leaking rear seal and after skid plate removal might have a front seal leak too. After drive shaft removal and inspection very little play in that assembly. Has 167,000 on it, but still in very good condition. Any suggestions? I want opinions before I either buy a rebuilt transfer case or take the front end apart.

 

[Sams01XplrSprt]

welcome dc

 

[junoflydog]

I had a similar problem with a '98 AWD but was loudest at low speeds. This is my posting.

http://www.explorerforum.com/forums/showthread.php?t=203179


The summary is -

The front drive shaft has a U-joint on one end, and a CV joint on the other. The CV end had no grease and the balls had worn a small groove in the metal. I believe what was happening was the balls would slip out of the grooves when they became non-torqued, then pop back into the grooves when they torqued back on each revolution of the drive shaft. That explains why I got 2-4 consistent major clunks per tire rotation.

 

[Nexor]

have the same problem with my 98 at 80k miles.

had the front shaft rebuilt and noise got a lot quieter but still persists. Also Had both front end CV axles replaced with new ones but noise is still there only at low speeds. New hubs was my next move. I also have the rear two transfer case senders next to the case motor with very very slow leaks that have not been fixed yet. Don't think it's my transfer case though cause I hear the noise loudest next to the passenger side firewall. I was going to take off the front shaft and drive around with it off to see if the noise is gone or not.

I'll be following this thread closely

 

[Jameskennedy]

Check for tires out of round, then check the hub bearings.

 

[corkey]

i had a similar sound from the front of my Ex too,except with a high speed shudder, it drove me crazy for about 2 months trying to fix it, the problem was i never found out what was causing it,, i had done a new hub and new brake pads and rotors up front and thought that was what it was, so i took it all apart again, and put it all back , it was still there, ,

i know this sounds kind of simple, , but i rotated the tires and the noise went away after that ,
could have been the wheel nuts or a tire , the front passenger side was a bit worn on the inside,
also i noticed the toe in was a bit much before i did some torsion adjusting, after i did the shackles,
so in conclusion , i think it was the tire

 

[98formulaLS1]

you could put the vehicle on 4 jack stands, and have a friend get the speed up to 50MPH while you check out the source of the noise underneath.

 

[Cobraguy]

you could put the vehicle on 4 jack stands, and have a friend get the speed up to 50MPH while you check out the source of the noise underneath.

Be careful...that can be dangerous. But it's worth a try if you're careful. I'll bet it doesn't show up though without a vehicle load. I would do as suggested...I'd try different tires and see if it helps.