EPAS Terrible Shudder

[Sky Render]

I've talked to many movers and shakers in the aftermarket about this issue. If you have changed the front LCA bushings in your 2011+ GT or Boss or GT500 it will bork up the EPAS software. I am about to do the front bushings again on my 2013 GT (the stock bushing is a big hydraulic marshmallow and screws up geometry under braking and cornering), and once again will probably have to buy the $999 racing steering rack (which is a stock rack without the goofy software issue).

If/when Ford will step up and offer this revised "Race" software for normal street cars is anyone's guess. Likely never.

Good luck,

Did swapping to larger-width wheels and tires cause an issue? I want to run wider tires, but I'm terrified of making my car undrivable. And that shudder of death equals undrivable in my book.

 

[db4z]

As I mentioned in an early post, I went from stock 18" wheels to 19x9 and 19x10 wheels with 255/40R19 and 285/35R19 tires and get the shudder randomly. It seems to depend on road surface more than speed and is only really noticeable when I take my hands off the wheel. Suspension is stock.

 

[Sky Render]

As I mentioned in an early post, I went from stock 18" wheels to 19x9 and 19x10 wheels with 255/40R19 and 285/35R19 tires and get the shudder randomly. It seems to depend on road surface more than speed and is only really noticeable when I take my hands off the wheel. Suspension is stock.

255s up front is not really very wide, though. Some corner carvers run 285s or even wider.

 

[Vorshlag-Fair]

255s up front is not really very wide, though. Some corner carvers run 285s or even wider.

Yes - and on these big cars, the wider the better! Even 315mm tires can fit an S197, with the right wheels/offset and a little negative camber up front. Our red 2011 GT (below) is on 315s at all 4 corners, but unlike a lot of other S197 Mustangs in ESP, these actually fit under the fenders.

My 2013 GT's street tires are even 295s...

These are on smaller 18x10" wheels, which is easy to do.

 

[Sky Render]

Did adding wider tires affect that EPAS problem at all? Or were all the issues caused by the bushings?

 

[BHD]

Dang! now I know what EPAS is lol! Sub'd!! I am afraid I might get the shudder problem on my 2013, I didn't face any yet
I run 20x11 20x9 265/35/20 305/30/20, and my future suspension upgrade in the signature.. no front LCA upgrade for me, I will face any problem?

 

[Vorshlag-Fair]

Did adding wider tires affect that EPAS problem at all? Or were all the issues caused by the bushings?

Nope. The shudder started after the aftermarket front LCA bushings were added to our 2011. It would happen with the stock tires, wider street tires, and race tires... but once the shudder symptoms began it would be worse during racing conditions. So bad it would go into limp mode. It wasn't race-able when it got all jacked up like that, and we'd have to limp the car back to the pits, shut off the engine, restart it, reset the traction control (off), and go back out. It would also shudder no matter what traction control setting we had.

On my 2013 with the 295mm street tires, camber plates, but the stock LCA bushings it hasn't happened (yet), and I've tracked the car pretty hard. It seems to always be tied to the front LCA bushing swap, from many many S197 owners I've talked to. Stupid EPAS programming flaw...

 

[choate]

All very interesting. Mine had the steering wheel shutter at first but since a road force balance that has all but gone away but the seats still shake on grooved roads. Sometimes worse than others. It's weird. I can sometimes see my sunglasses clip shaking and my pant legs and shirt if I look down. I didn't notice this at all until after I got aftermarket wheels but i can't say it happened exactly after they went on. I can say however, that even after a mild drop (BMR springs), Koni's and camber bolts, the shutter is about the same and not any worse. I will say that the tires that came on my rims are crap. I'm running 255/35/20 and factory was 245/45/19 so that's slightly off too. My original theory was that slight tire height difference, along w/ my crappy tires were causing an issue but that is yet to be seen since I have a 2nd car now I drive daily and the Stang only sees action on the weekends. I'm subcribed though and want to say thank you to Terry for the great research! I'm fairly active on allfordmustangs.com but new here. Great site for info!

 

[Sky Render]

Nope. The shudder started after the aftermarket front LCA bushings were added to our 2011. It would happen with the stock tires, wider street tires, and race tires... but once the shudder symptoms began it would be worse during racing conditions. So bad it would go into limp mode. It wasn't race-able when it got all jacked up like that, and we'd have to limp the car back to the pits, shut off the engine, restart it, reset the traction control (off), and go back out. It would also shudder no matter what traction control setting we had.

On my 2013 with the 295mm street tires, camber plates, but the stock LCA bushings it hasn't happened (yet), and I've tracked the car pretty hard. It seems to always be tied to the front LCA bushing swap, from many many S197 owners I've talked to. Stupid EPAS programming flaw...

Thanks Terry! Now I can upgrade from 255s to something beefier!

Sent from my toilet using Tapatalk

 

[BHD]

Today I made the same test in the video, speed over 55mph, steer left right left right left right, and NO shudder was there, phewwww

 

[applesauce683]

Thought I would update this. Installed the M3200-EPAS rack and the shudder is gone. Thanks Vorshlag for the continued R&D.

 

[Sky Render]

What caused the shudder in the first place? Did you install stiffer bushings on the front suspension?

 

[applesauce683]

What caused the shudder in the first place? Did you install stiffer bushings on the front suspension?

It started to happen after replacing the front control arms with BMR's.

 

[Jefro]

I'm about to do the Steeda x11 ball joints and bumpsteer kit so I will post if it is corrected. Although mine seems to be worse when it is above 85* so I might have to wait since it is snowing here.

 

[My08Stang]

What caused the shudder in the first place? Did you install stiffer bushings on the front suspension?

I have this on my extended christmas list... Thanks for the update.. I have hope, now...lol

 

[5.0_SD]

Reviving old thread...Terry, have you done the bushings on your 2013 yet? Has your 2013 started the shudder of death yet? Any programming updates? Anyone else have this issue on 2013-2014's after doing suspension mods?

 

[Bud]

Additional question, looks like the EPAS goes into safe mode if you disconnect the harness for it and basically operates as a manual rack. Anybody try this and does the car go into limp mode or not? Guessing it can be tuned around or runs fine for people doing manual rack conversions...

 

[unit5alive]

I've never had this problem on my 2013 boss , but in feb/march of 2012 the 2013 boss 302 mustangs (possibly other models?)were held from being shipped for well over a month because of this , and stripe issues on the hoods.

 

[Don's Stang]

I was searching for something else and stumbled upon this thread

On my 2001 Automatic, with stock suspension other than steeda upper strut mounts, and Koni yellow shock, I recientlly got a deal on a set of Boss 302 wheels, so put 265/40/19 fronts, and 275/40/19 Michelin Pilot Supe Sperts on. I imediatlly noticed the rear axle was not centered, offset to the drivers side.

After I installed the tires/wheels, I got the samee two traction control lights that Terry had, two or three times, and I noticed it had a vibration on the highway. Since I didn't like the drives side rear tire sticking out, I ordered a Steeda adjustable pan hard bar, pan hard brace, and the front lower G-Trac brace(since I lost the strut tower brace because of the roushcharger). Now with a centered rear axle, and G-Track barce, the vibration disapeered, as well as the traction control lights have not come on since. My steering also feels lighter, takes less steering imput, and tracks straiighter than before.

I don't know if my wider tires, being off centered was confusing the EPAS system, but have a feeling it was. Just goes to show how sensitive this system is to something so small

 

[Sky Render]

I was searching for something else and stumbled upon this thread

On my 2001 Automatic, with stock suspension other than steeda upper strut mounts, and Koni yellow shock, I recientlly got a deal on a set of Boss 302 wheels, so put 265/40/19 fronts, and 275/40/19 Michelin Pilot Supe Sperts on. I imediatlly noticed the rear axle was not centered, offset to the drivers side.

After I installed the tires/wheels, I got the samee two traction control lights that Terry had, two or three times, and I noticed it had a vibration on the highway. Since I didn't like the drives side rear tire sticking out, I ordered a Steeda adjustable pan hard bar, pan hard brace, and the front lower G-Trac brace(since I lost the strut tower brace because of the roushcharger). Now with a centered rear axle, and G-Track barce, the vibration disapeered, as well as the traction control lights have not come on since. My steering also feels lighter, takes less steering imput, and tracks straiighter than before.

I don't know if my wider tires, being off centered was confusing the EPAS system, but have a feeling it was. Just goes to show how sensitive this system is to something so small

Considering the fact that it was your REAR tires that were off-centered, I would wager that it had nothing to do with the EPAS system. Furthermore, a "G-trac brace" is already installed on 2011+ cars.

Also, I've run quite a few different widths of tires and have never had an issue.