My 5R55S is yelling at me...

[mitchness]

I have a 2004 XLS with 4.0 v6 engine.

I replaced both front wheel bearings and WHOLE front diff with axles and all exactly one year ago and I think it a hub may be going again, but enough of that.

I can't accelerate like I used to off a corner without the auto 4x4 kicking in and out and just making awful thumping noises like it's binding (almost acting as if you locked your manual hubs in 4x4 in your old truck but still drove around in 2wd).

I decided to check out the 4x4 system in my driveway and this is what I got:

Put in neutral, hit 4x4 low, waited for light to go out, reversed a bit, went forward. All went well and it acted as it should (enough torque to rip a house off the foundation)

Did the same and selected 4x4 normal and this is where the sounds kicked in. I decided to leave it in 4x4 and wait for traffic to go away on a quiet road and did a "normal" speed take off (like at a red light in traffic). With the windows down, you can't hear anything. With the windows up, you can hear a hum during a normal load take off. You can also FEEL it as if it's struggling.

117,000 miles. Bought at 96,000. I had Meineke do fluid/filter flush and refill with the GOOD brand anyways after I first felt the vibration (assuming nobody ever touched it before.) It has since then gotten a little worse.

Checked differential fluid levels, fine. (Remember whole front diff/axles were done at 108,000 miles).

Checked U-joints, fine. Cleaned and checked all wiring, fine. No loose wires. Even a volt meter told me so.

Popped truck up on 4 jackstands, all modes in any gear selection made all 4 tires spin equally. I don't think this is normal, but it could also be related to rear wheels spinning feely and auto engaging it as normal.

This hum feels like a power loss. It is annoying. It doesn't sound good!

Once fixed, I'm going Brown Wire Mod. This auto 4x4 is a bad design idea, but I love my Explorer!

 

[Flag Gibby]

You have done a good job of checking all the right things. Check your ABS snap rings and sensors to make sure that they have not come loose or have missing teeth as that can cause the auto function to kick in and out. Also, from your discriptions it sounds like you have an issue in the transfercase with the normal ratio gear staying enguaged.

 

[mitchness]

I will check those tomorrow because I drive like a crackhead 5 minutes late to a score on Black Friday. I also plan on putting my phone in the wheel well and setting a video to record. I will post it when I do that.

I did forget to mention one thing. When you turn the wheel all the way to the right and go forward and reverse you hear a "RRRRRRRRRRRRK" noise once in motion. It's almost like the tire is rubbing on the wheel well, but I know it's not. Factory rims, size tires, and nothing hanging loose. It might be that sensor stripped??? Only does it going to the right, and only for super sharp turns, which are kind of rare for me anyways. I tend to be nice to my power steering and not crank it out much or turn while stopped.

 

[Flag Gibby]

It is not unusual for the power steering to make noise on the older models when locked all the way to the left or right. Also, under hard lock to the left or right the joints in the half shafts can bind and make a bit of noise, but again not unusual. In your case I don't think that you should have the half shafts binding in the front because the vehicle is in 2WD and they should not be under load so again it sounds like the transfercase is acting up.

 

[mitchness]

Oh I know but this isn't an ordinary noise. It's a "crunching grind" and it may help root this issue or bring up another causing the one I have. I'll find a parking lot and zip tie my phone to the frame or something and record it. should be pretty clear. I'll post a youtube link. maybe 20 seconds or so in length.