rear diff clunk

[justinf89]

I just replaced the rear pads and rotors yesterday on my explorer and gave the rear hub a spin on each side. The first thing I felt was clunk clunk clunk.

With both rotors off each side, spinning the hub by hand, I can hear and feel a clunk probably 8-10 times per revolution, and it sounds like its coming from the diff. The faster I spin it the louder it is. Is this a common problem? I can take a video with the sound if anybody can help. Thank you, Justin.

 

[Smokefan1977]

Are you sure it's not a u-joint. Might be something to checkout.

 

[justinf89]

Definitely something I will look at tomorrow. That would be a nice easy fix too.

 

[justinf89]

Ok jacked it up again today and the driveshaft doesn't turn when I turn the rear wheels, just the opposite wheel so it can't be the u-joint making the noise. What else could make a rhythmic tapping like this?

 

[justinf89]

Alright well I've decided that I'm going to go ahead and change out the rear wheel bearings on wednesday. If it's not that, it's too much for me to deal with right now anyway.

 

[SXE10]

I used to work at a Ford dealership, good chance it's your LSD. We used to do lots of rebuilds on them. Usually just a plate kit that's required. You could try some Redline 80w140 in it & see if that shuts it up

 

[justinf89]

Ha I wish I had an lsd, it's an open 3.55.

Oh yea, and welcome.

 

[mechtech2]

Were both wheels off of the ground?
One wheel will spin opposite.
Everything could be normal.

 

[justinf89]

Yep but it still clunked like crazy

 

[SXE10]

If you've no LSD then I'd say it could be the diff bearings are had it. Only way to tell is to open her up. Maybe have a chat to your local Ford dealer. It may just be that quality '90s Ford build quality & there's nothing to worry about

 

[Warstud]

Are you sure it isn't the pads you just replaced?

 

[GMBoy]

I would just change the fluid and see if that helps first.

 

[Rand]

does it make the noise with the driveshaft turning the wheels or only when you are manually rotating one wheel?

 

[justinf89]

With both rear rotors removed, only hubs showing, turning them by hand. The driveshaft doesn't turn when I do this.

Edit: When I first got the explorer 20k miles ago, I immediately noticed it had a slight roar/vibration from the rear on the highway. I've probably gotten used to it though but I don't hear the thumping when going down the road.