How to detect worn panhard bushing? Do they transfer noise from the diff?

[GriffX]

I touched a curb in a corner very hard right rear, only a bad scratch mark at the tire, but the car develops a white noise from 50 mph up, cannot say if it is from front or rear. I removed the panhard to inspect the bushing, they were a bit twisted, but no cracks. Looks like they have been installed not on curb height some time ago. Tube looks straight

Noise is not dependent on cornering or clutch engagement, only speed. I'm afraid it is a differential carrier bearing.

Thanks!

 

[BottleRocket]

I rebuilt the diff 3 times on my 1st '08. It was bad when I purchased it, it went out again 20K later, then it went out again 30K later. I complained about this to my local Ford service center and they assured me there were no recalls on the diff bearing. I discovered several years later that Ford redesigned the pinion bearing, don't know why. It probably has something to do with pinion bearing failure being fairly common on '05-10 (?) Mustang diffs. Just a heads up.

 

[GriffX]

I had that bad pinion bearing some years ago and had to rebuilt it by myself (almost impossible to find a workshop for rear axles in Germany). I remember the new bearing had one roller less than the old, but I don't know anything about a revision.

The noise is different now, it's more like an additional wind noise and it's everywhere. The bad pinion bearing had a resonance 45-55 mph. The noise now is increasing with speed up to the exhaust wins

Thanks

 

[GriffX]

Did a visual inspection yesterday, seen nothing except I noticed that the rear brake disks wear quicker than the front. After a very gentle 3 miles city drive I touched all brakes and right, the rear disks are definitely warmer than the front. Measured with infrared, 40°C rear, 30 front. Hmmm....

 

[Pentalab]

Did a visual inspection yesterday, seen nothing except I noticed that the rear brake disks wear quicker than the front. After a very gentle 3 miles city drive I touched all brakes and right, the rear disks are definitely warmer than the front. Measured with infrared, 40°C rear, 30 front. Hmmm....

Something amiss there. The fronts always run way hotter than the rears.

 

[redfirepearlgt]

Touched? Is that an accurate statement or an understatement? Touching a curb only hard enough to scuff a tire is not going to cause damage unless an issue was already there and about to fail anyway. So how hard was the impact? Did the car impact the curb at a high rate of speed because you lost control possibly showing off as many of us do and/or have done? Or did you merely misjudge a corner taking a turn and slightly curb the tire only leaving a scuff in the rubber? The latter is likely nothing and you are only now overly sensitive to noises already present. The former if you impacted the wheel during a skid into the curb may have caused some damage. With vague inquiries comes vague answers.

 

[dark steed]

Touched? Is that an accurate statement or an understatement? Touching a curb only hard enough to scuff a tire is not going to cause damage unless an issue was already there and about to fail anyway. So how hard was the impact? Did the car impact the curb at a high rate of speed because you lost control possibly showing off as many of us do and/or have done? Or did you merely misjudge a corner taking a turn and slightly curb the tire only leaving a scuff in the rubber? The latter is likely nothing and you are only now overly sensitive to noises already present. The former if you impacted the wheel during a skid into the curb may have caused some damage. With vague inquiries comes vague answers.

I think he means he physically touched the discs with his hand after driving to judge the temperature.
It sounds like you may have a rear caliper dragging. I had that happen on mine and ruined a set of drilled/slotted rotors. It was the inside pad dragging, so it didn’t visibly show up until the pad was into the rotor


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[Pentalab]

I think he means he physically touched the discs with his hand after driving to judge the temperature.
It sounds like you may have a rear caliper dragging. I had that happen on mine and ruined a set of drilled/slotted rotors. It was the inside pad dragging, so it didn’t visibly show up until the pad was into the rotor


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He said he used a point + shoot IR. Mine works good for that application, and a lot of other applications.

 

[GriffX]

I touched the curb rear right at 35 mph quite hard, a right corner. Curb was lower than the rim so only rubber was hit, but the car made a little jump to the left.
I did a visual inspection and removed the panhard, I thought that gets the hardest hit (?) Panhard was straight, bushings looked a bit twisted, like someone has not tightened the bolts on curb heigh.

Short after that incident I did a 800 mi vacation with 70-80 mph speed. During that trip I noticed that increased road noise.

Yesterday I noticed that the rear breake disks are more worn than the front to verify this I measured the disk temperatures after a gentle city drive today. Temp at rear is higher than front. I think this is odd.

I cannot localize the increased road noise, it is only speed related (no clutch, rpm or gear) and doesn't change in a corner, so I think it is not a wheel bearing.

 

[07 Boss]

Sounds like your rear caliper is dragging a bit. I had one that was stuck pretty good to the point where I smelled them before I knew anything was wrong. Could be the sound of your road noise if it's dragging. maybe the axle got tweaked a bit or the caliper is sticking. Either way check for run out on your rear rotors. Then check your caliper pistons.

 

[Laga]

Modern cars with traction control and especially stability control wear out the rear pads sooner than the fronts. The rear brakes get applied thousands of times without the driver even knowing it.

https://www.motorbiscuit.com/should-my-rear-brake-pads-be-wearing-out-faster-than-my-front-ones/#:~:text=That's because braking shifts the,to be stronger, NAPA explains.&text=But there is a reason,control and electronic stability control.

My local AutoZone guy says they sell more rear pads than front.

 

[GriffX]

The ESP cars or the BMW fake traction lock X-drive use the rear brakes a lot, true. I don't think this is the case on my 07 GT. My driving habit is not near by losing traction, but to rule this out I did the test drive very gentle.

Rotor runout is a good idea. Frozen pistons usually needs only new gaskets?

 

[E Turtle]

I touched a curb in a corner very hard right rear, only a bad scratch mark at the tire, but the car develops a white noise from 50 mph up, cannot say if it is from front or rear. I removed the panhard to inspect the bushing, they were a bit twisted, but no cracks. Looks like they have been installed not on curb height some time ago. Tube looks straight

Noise is not dependent on cornering or clutch engagement, only speed. I'm afraid it is a differential carrier bearing.

Thanks!

 

[E Turtle]

After 26k I started getting a nice “ bump” as I shifted at many different rpm’s. Got the car on the lift and the factory upper control arm bushing had failed. Still have the lil clunk but that’s because the 09 Gt500 had a not so desirable drivetrain.
I can’t imagine you hitting a curb hard enough to damage a pan hard bar bushing. I visual check would be all you need.

 

[GriffX]

I'm not able to locate the noise right now, it is everywhere from the underbody, reminds me of a bad wheel bearing, but on all wheels, that is why I was thinking that the source has close contact to the body.

 

[GriffX]

Preliminary result: I did some roll test with engine off, engage e-Brake and it makes a lot of noise. At least the rear break is free for now, no dragging. But have not been on the Autobahn yet. Fuel is 8.50$ /gal in Germany right now, I'm not driving around for fun these days.

 

[GriffX]

It looks like it is a sticking e-brake. I turned the rear caliper pistons back in to free them up. The noise is gone now, so no problem with the diff, yay. I will use the e-brake now as usual, when the noise comes back, the caliper is probably damaged.

 

[Juice]

Check the caliper slides. I had them stick from rust three times now on mine. One rear pin was stuck when I got the car, from a dealer, who performed a $600 dollar used car service before selling the car to me. (I refused to pay for that, dealer ate it) They unhooked the one park cable as the fix, so they knew it.
Since than, I had a brake pull on my van.. You guessed it, stuck caliper slide.

 

[GriffX]

Will do that, Thanks!
Dealer stories can fill books. One did not torqued the big bolts at the front strut. They came lose after 1000 mi, that was fun

 

[GriffX]

I checked the calipers and runoff, looks like the parking brake mechanism was affected from the hit of the curb. It is working until now again and the noise is gone.
Thanks for the tips!