Whats this noise? Help please

[Ricky_Bobby]

I have been trying to narrow down this noise for months and can not get to the bottom of it. At first I tried the sway bar link ends as one bushing was shot. I replaced the complete rear brakes, including the e-brakes. Front pads and one rotor were also replaced.

I am thinking it may drive train related. When I took it for inspection in June the first shop failed it for needing the full exhaust system from the manifold back along with a bad front u-joint. They passed it for emissions even after saying I needed a full exhaust. Needless to say I took it to another shop who passed it. I want to eliminate the noise coming from the front u-joint due to the front drive shaft not spinning while driving on road under normal conditions.

The vehicle is due for differential fluid changes which I am planning on starting with the rear and transfer case fluid this weekend. I will take a look inside to see if any of the gears are grinding down or if there is excess play which could maybe cause this noise. The noise is only present under 20mph and does not make a difference if I am on the throttle or not, only easier to hear when coasting. It also does not go away when the brakes are applied. I was thinking maybe one of the pads could be loose which I will double check. Any thoughts on this possibly being related to a differential going bad, bad u-joint, or driveshaft? Any help is appreciated. The video is short and you can hear the clunking/clicking noise towards the end. This is a 05 6 cylinder with 186K miles.

Thanks,

 

[Tech By Trade]

Sounds like a U joint, front or back I couldn't tell you.

 

[Ricky_Bobby]

Does the front u-joint spin while driving in 2WD? This is a 4WD model.

What is best way to test for myself, jack up the rear wheels on jack stands then put it into neutral and try spinning the drive shaft while looking underneath?

 

[Joe in NY]

These explorers do not have an unlocking front diff. So regardless of drive selection the front diff internals and front drive shaft will always be turning.

 

[bizzs]

You posted that you replaced the back brakes but nothing was mentioned about parking brake. I had a similar sound today and narrowed it down to the parking brake. The parking brake cable expander that is inserted through the backing plate was not positioned correctly causing the brake shoe to expand when rpm's increased. The sound was almost identical as yours. I removed the cable and rubber insert and greased it. I reinserted the cable, adjusted brake shoes and problem was solved. Give it a shot and keep us posted.

Bizzs

 

[Ricky_Bobby]

Thank you everyone for the trouble shooting. Ended up being the front u-joint. When I crawled under to look at it I could bang it around with out the wheels off the ground. All the needle bearings from one of the caps were gone. All the info on this site was super helpful and got me through the replacement. I sprayed the bolts with penetrating oil the night before and everything came out as smoothly as possible.

Bizzs - I had to replace the parking brakes back in May. I was only doing the rear pads and rotors but once I got in there, the parking brakes were pretty ugly. I am getting a minor noise, feeling when i am take long left turns which I think might be related to the parking brake. Feels like a small rubbing. I never use it and would take it off but Pennsylvania state inspection requires it. One day when i feel like it, I will look further into it. Thanks for the suggestion.