Hello,

I'm seeking a little advice on a problem I've been having for about a month with my 1998 Lincoln Navigator 5.4L 4x4. Every time I turn left, there is a creaking/rubbing noise coming from the rear and cannot tell what the cause is. There is no noise when driving straight, over bumps, or even turning right everything is normal -- only during left turns. The noise is brief and happens in the middle of the turn just as I begin to accelerate after completing the turn. Also when stopped with wheel turned all the way to left, the noise happens as I accelerate.

Some steps I've taken so far:

I lifted and supported the vehicle and checked rear wheels for play, there was no looseness in any direction on either wheel. Removing the wheels and inspecting the suspension, no signs of leaks and no signs of damaged components. Trailings arms, rear sway bar bushings and end links and other bushings look ok. No signs of leaks at the axle or at the wheel hubs. Rear brake pads and brake rotors looked normal, no abnormal wear, no stuck calipers and normal pad thickness.

One apparent problem I found, rear parking brake shoes were seized on inside of right rear rotor, I thought this was the cause of the noise and I replaced the shoes and hardware and adjusted parking brake but noise still there.

Changed rear differential fluid with 75w-140 gear oil but noise still persists. Also changed front differential fluid and transfer case fluid as a side note but no effect.

And at this point out of ideas, maybe better to ignore the noise and just live with it? I also changed some worn suspension parts in front (air shocks, tie rod ends, balljoints, upper control arms), but did not effect the noise in rear. Just added this here to emphasize noise not coming from front.

 

May be the drive line???


Is there any difference on loading? Like if there were several people in it (several hundred extra pounds) would it still make the noise?


>>>>>>>Action

 

I would focus on the parking brake shoes.

 

I am not sure but the driveshaft looks ok, did not seem loose or have any play.

 

I installed new parking brake shoes and hardware today and reassembled everything but noise was still present during test drive.

Could a differential problem cause this noise?

 

"Also when stopped with wheel turned all the way to left, the noise happens as I accelerate."


Can you duplicate the noise by turning to the left with your foot on the service brake so the vehicle does not move and then accelerate?


>>>>>>>>>Action

 

Accelerate with the brake pedal or the parking brake applied?

 

Regular brakes, NOT parking brake.


If you can duplicate the sound with the vehicle NOT moving you have more possibilities of discovery.


>>>>>>>>Action

 

This prolly has the LSD. Has it had any additive added to the diff fluid?

 

And if that's the case, put two bottles of additive in.

 

Upon more careful observation of trying to replicate the noise, am more convinced the noise is from the rear differential. I bought some motorcraft friction modifier and will see what the results will yield and hope for the best. When stopped and wheel turned fully to the left or fully to the right and then accelerate, the noise happens every time, like a grabbing/grinding/creaking noise.

Also a different problem I've had for a longer time (maybe a year or so), there is also a whine from rear, apparent at speeds above 25 (and very apparent at around 70 mph). Maybe a bearing noise or maybe the rear differential? I had a bad wheel bearing on a different vehicle and was more of a growling/roaring noise, very different than this. I left it alone for all this time since I've never had any other signs of problem, no grease or fluid leaking around bearings or play, but maybe this was the issue all along.

 

+1 on the LSD.


>>>>>>>Action

 

Took vehicle for test drive after adding friction modifier and noise is gone


Thank you for the comments and suggestions!

 

You will likely start to hear it again within 30k or so, just repeat as needed. Two bottles are better than 1.

 

I just registered to put in my opinion here.... I reccomend you add the least amount of Ford track loc additive necessary; because the more you add the weaker your track lock is. Too much additive will make it act like an open differential.

When I changed my Navi rear end fluid I put in half a bottle, and so far no noise. It was chattering a bit before so I think the fluid was old. Everything can very especially with how worn the clutches may or may not be.