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EXTREME Shake on Braking

6K views 22 replies 14 participants last post by  FordService 
#1 ·
So, driving to work this morning, doing about 50-55 or so (wasn't paying much attention to speedo), when a cat darts out in front of me. Now mind you, I'm not going to sacrifice my life, or lives of others by attempting some dukes of hazzard maneuver, but I am going to do my best not to hit an animal. In this case, it required a heavy dose of braking....this is where the fun starts. I kid you not, the steering wheel shook so hard from side to side, that I thought something had broken in the steering/suspension system. This was not a shimmy, a rotor needing to be turned, irregularity in the road. This was a VIOLENT shake. Thinking that something had come loose in the steering department, I immediately manuevered the car to the right hand side of the road, where I am ashamed to say, made very slight contact with a parallel curb, scuffing it a bit.
Has ANYONE ever experienced, seen or heard about this? I saw the 'shimmy' thread in regards to Sport mode, and this isn't that...
Thanks in advance yall, and sorry for the long post...

Oh, and the cat made it okay.... :bigthumbsup
 
#2 ·
So, driving to work this morning, doing about 50-55 or so (wasn't paying much attention to speedo), when a cat darts out in front of me. Now mind you, I'm not going to sacrifice my life, or lives of others by attempting some dukes of hazzard maneuver, but I am going to do my best not to hit an animal. In this case, it required a heavy dose of braking....this is where the fun starts. I kid you not, the steering wheel shook so hard from side to side, that I thought something had broken in the steering/suspension system. This was not a shimmy, a rotor needing to be turned, irregularity in the road. This was a VIOLENT shake. Thinking that something had come loose in the steering department, I immediately manuevered the car to the right hand side of the road, where I am ashamed to say, made very slight contact with a parallel curb, scuffing it a bit.
Has ANYONE ever experienced, seen or heard about this? I saw the 'shimmy' thread in regards to Sport mode, and this isn't that...
Thanks in advance yall, and sorry for the long post...

Oh, and the cat made it okay.... :bigthumbsup

Mine does the same under hard brake. And yes - feels like bad rotors.
 
#4 ·
Mine does the same thing. I think its the abs.

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#6 ·
No its not the pads or rotors. My car does this and the rotors/pads are perfect. This only happens under rare panic brake conditions. You wont brake this hard anywhere not even on a race track because after two laps you would be out of brakes.

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#9 ·
lestat, It sounds like you know what you're talking about but it's easier to ask than not, was it abs? some cars are more violent than others with the brake pulsing (not intended as an insulting question) If it you can recreate it and know it isn't the abs I'd take it in to be looked at...
 
#10 ·
Thanks everyone for your replys. Couple of things:
I was going straight when I braked hard, so unless it percieved a turn that wasn't there, I don't think it should have tried to keep me straight. And as of yet, I don't think I've ever activated ABS. But on the many other vehicles I've driven when I did activate ABS, if I felt any kind of pulsing, it was felt in the brake pedal, not in the steering wheel. This was more of a left/right shake. I never felt anything in the brake pedal.
On another note, I'm really irritated that I've scuffed the rim; I've babied this thing...:weeps
Someone at work was telling me that a friend of his (I know, I know) had to have his GT500 'reflashed' due to an anomaly similar to this, as was covered in a TSB? Can anyone validate this?

Thanks again!
 
#11 ·
Bunch of people in here that have no idea how ABS works, and that's kinda sad.

ABS, if functioning correctly, should never affect how the steering wheel feels. In fact, the whole point of ABS is so that you retain full steering control during a panic stop.

I too have felt bad/warped rotors, and what you're talking about doesn't sound like it - and if it was, the steering wheel would shake violently at even the slightest application of brakes.

What you're describing sounds like a fairly serious malfunction of the ABS system. Remember, both stability and traction control rely on the ABS system for inputs. If it isn't functioning right, it can cause the stability control to do all sorts of weird things - such as shake the steering wheel violently when you activate the ABS during a panic stop.

The solution is to take the car into the dealer - it has a problem that a wrench isn't gonna solve. Sounds like you need a new ABS module. Does your ABS light ever light up?
 
#12 ·
I've had the same issue. Dealer hasn't been able to give me any reason as to why it happens. It's worse when braking really hard in a turn. Good luck finding out what's going on. The GT500 has a TSB for this issue and it's a reflash of the EPAS system. I can only hope that Ford puts out one for our cars as well.
 
#13 ·
Guess it's time for an appointment at the dealer....dang
And I kinda know the answer to this already, but I still got to throw this out there. You think that if/when they find a problem, that my rim could be replaced, since it was a direct result of a failed piece of equipment? I realize that it's a long shot, but.....
 
#16 ·
I've had this exact same thing happen more than once. Like someone else said it's worse when you're also turning a little while braking. I drive with the AdvanceTrac completely off 99% of the time so it shouldn't be the stability control kicking in. It was doing it when I was at a road course a couple weekends ago too with the AdvanceTrac completely off. I seriously doubt my rotors are warped with only 6k miles on the car, plus with light to medium pedal pressure the brakes are smooth, no pulsing at all.

It did it on the street a few times long before I took it to the track so I don't think it's because of too much heavy braking either. I have a Brembo car so I have the same brakes as the GT500 so I wonder if it's related to their TSB. It doesn't do it every time though so I'm not taking it to the dealer to have them stomp on my brakes a bunch of times to try to recreate it.

Edit: I wonder if this could have anything to do with it... http://www.automd.com/tsb/bulletin_b37502/

Edit #2: This is also the same TSB that shows up on GT500s... http://www.automd.com/tsb/bulletin_b199601/
 
#17 ·
I have a 2010 Mustang GT and I'm going thru the same thing. It just started last week, my GT has 16k miles on it.

My dealership had the car all week and replaced the drivers side rear axle (no idea why) they said it was bent and was the issue, NOT!

They turned all the rotors and force balanced the tires and checked alignment, disconnected ABS checked all front end parts. when I picked the car up my service manager said its still there but no sense in this car sitting in the back lot all weekend when you can keep it in your garage. He knows Im very picky.

Initially when I picked the car up I thought it was actually gone, but the next time I used my brakes the wheel shimmies back and forth on braking pretty bad, and I cant feel it in the car only in the wheel. The dealership knows what I'm talking about they see what I'm telling them is true, but have no idea how to fix it or whats causing it. They keep saying Ford engineers are advising them. blah blah!

Anyone got some suggestions? This is going back to the dealership Monday!! :sterb:
 
#18 ·
I have a 2010 Mustang GT and I'm going thru the same thing. It just started last week, my GT has 16k miles on it.

My dealership had the car all week and replaced the drivers side rear axle (no idea why) they said it was bent and was the issue, NOT!

They turned all the rotors and force balanced the tires and checked alignment, disconnected ABS checked all front end parts.

Initially when I picked the car up I thought it was actually gone, but the next time I used my brakes the wheel shimmies back and forth on braking pretty bad, and I cant feel it in the car only in the wheel. The dealership knows what I'm talking about they see what I'm telling them is true, but have no idea how to fix it or whats causing it. They keep saying Ford engineers are advising them. blah blah!

Anyone got some suggestions? This is going back to the dealership Monday!! :sterb:
Your problem is not the same as in the 11-12 Mustangs. Your car is still hydraulic power steering, not electric as the late models are.
The list to check would include ball joints, inner and outer tie rod ends, wheel bearings, rotor runout and parallelism, wheels and tires.

For the 11-12 Mustangs try removing fuse 45 in the underhood fuse box. It's a 5 amp fuse. This will eliminate the electric rack as a shimmy concern.

Be warned, though, you're taking a module off the CAN bus network and all kinds of codes will come up! Putting the fuse in and clearing the codes puts you back to normal.. not sure if your average scan tool is capable of clearing these codes. I doubt it, so a battery disconnect may be required.
 
#20 ·
http://www.allfordmustangs.com/foru...5-0-brembo-violent-steering-wheel-wobble.html

I noticed this about 2 months after getting my car, I can honestly tell you it does not affect stability or control, but will scare the frickin crap out of you, and could possibly rip the wheel out of weaker hands(someones GF, Wife, or an older person). I have only duplicated it 3 times and I am sure I could again, but have not come across a time in normal driving where it has happened. I came to my own theory. EPAS is unable to compensate properly when ABS kicks in on cars with BBP. I had no idea about a possible TSB on this, good to know! To those of you who think that this is a "normal characteristic" of ABS, you are completely wrong:nono:. It may however be a "Normal characteristic" of the 2011 mustangs built on June 5th after 2pm, but before 4pm.
 
G
#21 ·
cntxplne,
Thanks for the reply, but in my case, it would be like bad rotors on steroids. I've felt bad rotors, but this felt much worse.

Deysha, ever heard of this?
Mine does the same under hard brake. And yes - feels like bad rotors.
Mine does the same thing. I think its the abs.

Sent from my Droid using Tapatalk
No its not the pads or rotors. My car does this and the rotors/pads are perfect. This only happens under rare panic brake conditions. You wont brake this hard anywhere not even on a race track because after two laps you would be out of brakes.

Sent from my Droid using Tapatalk
I have had this happen to me on my car as well. For some reason I find myself coming up to corners way too fast from time to time. I do not feel anything out of the normal on normal braking.
I've had this exact same thing happen more than once. Like someone else said it's worse when you're also turning a little while braking. I drive with the AdvanceTrac completely off 99% of the time so it shouldn't be the stability control kicking in. It was doing it when I was at a road course a couple weekends ago too with the AdvanceTrac completely off. I seriously doubt my rotors are warped with only 6k miles on the car, plus with light to medium pedal pressure the brakes are smooth, no pulsing at all.

It did it on the street a few times long before I took it to the track so I don't think it's because of too much heavy braking either. I have a Brembo car so I have the same brakes as the GT500 so I wonder if it's related to their TSB. It doesn't do it every time though so I'm not taking it to the dealer to have them stomp on my brakes a bunch of times to try to recreate it.

Edit: I wonder if this could have anything to do with it... Service Bulletin 37502 for Ford POWER TRAIN | AutoMD

Edit #2: This is also the same TSB that shows up on GT500s... Service Bulletin 199601 for Mercedes Benz SUSPENSION | AutoMD
You can always go on the test drive with the Tech and you drive it.
I have a 2010 Mustang GT and I'm going thru the same thing. It just started last week, my GT has 16k miles on it.

My dealership had the car all week and replaced the drivers side rear axle (no idea why) they said it was bent and was the issue, NOT!

They turned all the rotors and force balanced the tires and checked alignment, disconnected ABS checked all front end parts. when I picked the car up my service manager said its still there but no sense in this car sitting in the back lot all weekend when you can keep it in your garage. He knows Im very picky.

Initially when I picked the car up I thought it was actually gone, but the next time I used my brakes the wheel shimmies back and forth on braking pretty bad, and I cant feel it in the car only in the wheel. The dealership knows what I'm talking about they see what I'm telling them is true, but have no idea how to fix it or whats causing it. They keep saying Ford engineers are advising them. blah blah!

Anyone got some suggestions? This is going back to the dealership Monday!! :sterb:
http://www.allfordmustangs.com/foru...5-0-brembo-violent-steering-wheel-wobble.html

I noticed this about 2 months after getting my car, I can honestly tell you it does not affect stability or control, but will scare the frickin crap out of you, and could possibly rip the wheel out of weaker hands(someones GF, Wife, or an older person). I have only duplicated it 3 times and I am sure I could again, but have not come across a time in normal driving where it has happened. I came to my own theory. EPAS is unable to compensate properly when ABS kicks in on cars with BBP. I had no idea about a possible TSB on this, good to know! To those of you who think that this is a "normal characteristic" of ABS, you are completely wrong:nono:. It may however be a "Normal characteristic" of the 2011 mustangs built on June 5th after 2pm, but before 4pm.
Hey lestat210,

No, I have not heard of this personally. I do recommend you make an appointment with your Ford dealer and private message me with your dealer, VIN, mileage and contact info so I can escalate this for you and help get it resolved. This also goes for cntxplne, monolith, Spacemonkey, erod550, 1972 Mach1, and adspru.

Deysha
 
#22 ·
You can always go on the test drive with the Tech and you drive it.



Hey lestat210,

No, I have not heard of this personally. I do recommend you make an appointment with your Ford dealer and private message me with your dealer, VIN, mileage and contact info so I can escalate this for you and help get it resolved. This also goes for cntxplne, monolith, Spacemonkey, erod550, 1972 Mach1, and adspru.

Deysha

Deysha, first off, thank you for being here for us, it is appreciated! But that being said, even I don't like driving the car to duplicate this one! I can only image the look on the technician face as I shave speed so fast his eyeballs pop out of their sockets:ahhhhh. To those who don't mind duplicating it, please report back if you have been able to have this resolved. As I stated earlier, I just assumed it was a "normal characteristic" that I can live with due to the extreme nature of when it occurs. I highly doubt my wife could even push the pedal down hard enough to make it happen, now my girlfriend on the other hand is a little younger, she probably could:heha:!
 
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