help - rearend noise

[Titleistman]

Okay. I have replaced the brakes, rotors, parking brakes and rear wheel bearings with all parts being OEM. At this point I am still getting a noise from the right rear that is cyclical with the turning of the axle. It is the woo, woo, woo that has been described a thousand times. I have no idea what this could be at this point. With the rear end off the ground and spinning the tire it is just the normal sliding of the pads on the rotors. It isn't the dust guard rubbing on the rotor since this would be notiiceable just spinning the tires. The noise is constant whehter applying the brakes or not. It doesn't come or go with acceleration or decelertaion, but rather the cyclical sound gets faster with speed. It is not a hum, but more a scraping or grinding. I don't think the caliper is sticking. What would a sticky caliper sound like? Is it possible the rotor is not true? Any ideas on what this could be? I am not an expert, but I have been able to figure out most things quicker than my local garage and at a fraction of the cost.

 

[KPSquared]

When you changed your brakes, did you make sure the calipers could slide on the pins they mount with? Not sure if your rears bolt on or have the hammer in pins but if they bolt on, the metal tubes that the bolts go through need to slide freely in the caliper. If not, the first time you hit the brakes they can stick against one side of the rotor and either cause it to warp or just have really uneven wear. You put on new rotors so everything should roll straight... a "woo, woo, woo" would indicate something is bent/warped etc. A stuck caliper would probably not make a ton of noise but if the pad was pressed into the rotor for a while, it would get HOT.

Was this sound there before you changed everything?

Tire separating? How many miles on the rubber? Everything is balanced?

Bent axle shaft? Only asking because mine is bent but the slight wobble of the tire to go with the noise is very noticeable.

Is the noise for sure at the outside of the axle? Perhaps you have bearing issues in the pumpkin or even issues with the gears.

If you have access to an infared temp. gun, check the temperatures of everything after 20 miles or so of highway speed. Nothing should be overly hot. If something does happen to get really hot, your problem may be in that area. Probably not your outer bearing if you just changed that though.

Have you changed the diff fluid ever? Is there a limited slip in your axle or is it open?


Sorry for the long post, just thought I'd cover everything I could think of...

 

[Titleistman]

I didn't check and I do have the bolt on style. We actually rolled it out of the garage and went down the road without hitting the brakes to see if this was possible an issue. It made the same noise. I agree, the "woo, woo, woo does indicate something bent/warped.

I didn't notice the sound until I got the front bearings changed since they were very loud. Ever since I have been chansing the rear end noise with no success. I knew the brakes were need to be changed and I thought the parking brake was rubbing at first, but this hasn't been the case.

Tires are getting low, but nothing of any special interest. Maybe 35,000 on the current tires so I will need them soon. All seem balanced, but I can't be certain.

No idea on whether the axle shaft is bent or not, but I have never beat on the vehicle.

I can't be certain this is on the outside of the shaft, but it does seem to come from the right side and definitely in the rear.

I drove for an hour on the highway and was able to touch the rotor after being parked only 10 minutes. I didn't notice this being hot, but it could be since I don't have an infrared gun.

Ford changed the fluid when the TSB came about on the diff.. I don't notice a hum. It is open no special limited slip.

If I can get rid of this noise the vehicle will be very quiet.

 

[KPSquared]

If a tire is separating, it will make that noise and maybe not be visible to look at. If they are cheap tires, that is a good chance.

Doesn't sound like it's the brakes but I would make sure those pins slide so you don't wreck what you put in.

It may be a noisy gear set...

If the rotor wasn't hot, that's not your problem... I would more toward the center of the axle.

What was the TSB about?

 

[Titleistman]

Defnitely not cheap tires, but maybe I will get new ones sooner than later if this helps.

I can probably check the pins to be sure they are sliding.

The TSB was the older one about the diff fluid needing to be changed. The vehicle was still under warranty when I had this changed by the dealer.

 

[Titleistman]

I forgot to ask. This sound can be heard at real slow speeds. Wouldn't the tires normally get noisy at higher speeds?

 

[Titleistman]

calipers?

Okay. In case anyone is reading this thread. I noticed the rotors are wearing faster at the top than the bottom. I am starting to think the calipers might be partially sticking or not sliding properly. Does this make sense? It would make sense the noise is cyclical since the rotors are probably not perfectly true once mounted.

 

[Titleistman]

update

Dealer is saying the ring and pinion are toast. I will get it back tomorrow $1,100 later and I will post if the noise is removed. I hope so.