So, I own a 2010 Mustang V6 premium with 20 inch wheels. It has 75xxx miles on it and drives like a Champ. It is also my daily driver and over a period of time I have noticed an increase in the steering wheel shake while braking. Higher the speed I brake more the steering wheel shake it was. So, I have done following till now and got following results so far:
1) As a rule of Thumb, I got all the 4 wheels re-balanced and it helped with removing the steering wheel shake due to wheel imbalance while driving from say 55 to 65 mph but didn't help steering wheel shake while braking.
2) Got all 4 new rites installed along with the Wheel re balancing. So, getting all 4 new tires helped with the steering wheel stiffness a little bit and the ride is now smoother, but didn't help steering wheel shake while braking.
3) Replaced all 4 brake rotors with Power stop Z26 performance rotors. And also bled all 4 brake lines like hell and used DOT4 brake fluid instead of DOT3. Largely reduced the steering wheel shakes while braking, So now, I didn't have any steering wheel shaking while braking below 50mph. But steering wheel still shaking while braking over 50mph.
4) Replaced all 4 Brake calipers with Power stop performance Brake Calipers. Did not help with anything.
Now, with all of the above parts replaced and putting in a **** Loads of Money and time in this stupid Issue, I still have Steering wheel shake while braking above 50mph. While braking below 50mph I feel absolutely Nothing at all. It does feel like my steering wheel shakes more while I brake lightly and does not so much when I brake with full force.

I recently got it Check from two mechanic Shops and one of them told me that there is nothing wrong under the Car, my tie rods and control arms looks OK. However, the second mechanic told me that my Lower control arm shows some signs of wear and I should try getting them both replaced along with the Ball joints.

Now, I am on the brink of Braking off....... It is hard for me to believe any mechanic saying anything. Please Help !!! Should I go ahead and get my lower control arms and ball joints replaced???

This is very frustrating for me to keep on putting more and more money over and ever again into the same stupid problem in a car which is supposed to be well built, while my 2003 Nissan has 140K+ miles on it and not even a single problem. Brake Pads are the only thing ever replaced on it and that's about it, oh and it brakes wayyyyy better than mustang. I feel ashamed of buying an American car. Please help !!!

 

When you replaced the rotors, I assume you replaced the pads too?

If so, I'm out of ideas too and would suggest going to a Ford dealer.

 

Sorry you are going through this. Always frustrating to be throwing parts at a problem. The good news is that you have eliminated the most obvious causes, and set yourself up to go another 75k or more problem free.

There are really just a handful of other things that can cause this: ball joints, tie rod ends, maybe a control arm bushing, unlikely something steering related. All are decently likely candidates at 75k miles. Others will chime in as well, but I like TREs as the likely culprit.

No idea if you are in a major metropolitan area or BFE, but my best advice is to get it to a premium alignment or chassis type shop and have them diagnose this deal. If you are someplace like L.A. or Phoenix, this is easier than if you are in the middle of Iowa.

As for an American car vs. foreign car. This isn't a poor brand of car problem, this is a poor brand of service problem. Although the two are sometimes related at the dealer level.... ;-)

Best of luck. Try not to get too down on the whole thing.

 

I replied to your post on the other board also . . . one thing you might try, is to "bed" the new brakes. This will ensure that the brake pad material is evenly deposited on the rotor; if it is uneven, then there is a chance that might cause the shaking you are describing, especially on light braking. It is a long shot, but it is easy to do, so I thought it would be worth a try.

also make sure the rotors are sitting nice and flat and true on the hubs; no lumps of rust or crud in there to make the rotor sit at an angle

 

FWIW, I had a bad experience with Powerstop rotor/pads, not on my 'stang, but another 4 wheel disc car of mine. The P/S front rotors, on a downhill section coming to a fairly high speed stop, started shaking like crazy. They had been on the car for several thousand miles without an issue till this day. 20 miles later, at home, I pulled a wheel and the rotors looked trashed. Scraped up pad surface, bluing, looked like they had been through the ringer. Ordered up some cheap non coated Nakamoto ebay slotted and drilled units with their cheap semi met pads that solved my shaking brakes. I have a feeling Powerstops may not be a true upgrade.?. More like fancy advertising and colored rebuilt standard OEM calipers?
Another ebay drilled front rotor set I had on my brembo '11 GT went shaky at speed as well. Went with R1 concepts drilled GEOcarbon rotors which seem to be a true braking upgrade. The pads are a Rockauto closeout 'Satisfied" brand. The R1 rotors are Reasonably priced and working great on three of my cars now, I am a R1concepts convert customer. Not all brake rotors are quality, is what I am getting at...

 

That's the thing with the Power Stops, they have to be bedded before you start any regular driving. They suggest a series of starts and stop from different speeds to heat the brakes up, and if you have to stop completely during the process do not hold the brakes down (use the park brakes with tranny in neutral) as they will leave a mark on the rotors.Then 15 - 20 minutes of driving to cool the brakes off. Those instructions are there for a reason. Disclaimer: I ain't that smart Bert, I'm just preparing to buy some Power Stops for my C7 Corvette, and just read up on them. Some of the C7 owners say the Power Stops are leaving a bronze coating on their rotors, but I would bet the farm they didn't bed them in properly.

OP, might I suggest you check the front struts also. You've done everything else so looks like you're down to struts, control arms, etc. Maybe even the wheel bearings, at this point who knows. I do know it's hard to throw stuff against the wall to see what sticks, but look at it this way. When you get done the car should be good for another 100K miles. Good luck.