The Real Story of the 3.7L Mustang Stock Driveshaft Failure

After several websites picked up on a video posted by a 3.7L mustang owner who had removed his speed limiter and then proceeded run the car at high speed and break the stock Ford Driveshaft. These other websites, not concerned with actually learning the real story,  proceeded to label this guy an idiot and make fun of his misfortune. As a member of the 3.7L Mustang community I think this unfair treatment for a modification that many mustang owners make.

I have had several conversations with the owner and driver of this mustang and got the full and real story. Not just conjecture and silly forum nonsense. His story need to be taken seriously and to serve as a cautionary tale for other pioneering modifications on this new 3.7L Mustang platform.

 Here is the Video

2011 Ford Mustang 3.7L V6 Driveshaft fail at 135mph. It caused major damage including a hole in the metal floorpan, the exhaust system and muffler damage, broken transmission shifter, broken parking brake, and broken interior plastic trim parts.

He had posted this video and then took it down not expecting the rush of attention. Well someone had already copied it and re-posted it. The car is stock with exception to the SCT flash. It’s a loaded $33K automatic with the optional 3:31, 18″ Pirelli Z rated tires, Nav system, and rear camera. Earlier in the year he took it up to 135MPH and he think he must have let off just in time because ever since then there had been a vibration while coasting from 75+ MPH.

He didn’t know where the de-acceleration vibration was coming from. HE was actually worried that it may have been coming from the transmission. He had no idea that anything like that was going to happen. It wasn’t until after the driveshaft was replaced that he realized the de-acceleration vibration was completely gone, therefore he concluded that the driveshaft must had been damaged during an earlier speed run. He said he stayed on it longer during the first run, and was positive that it would have failed the first time. It was just a lucky day, and must have backed off just in time.

As a long time owner of multiple mustangs his purpose for posting was to warn other 3.7L mustang owners about the issue, prevent additional damage to these cars, prevent accidents, and possibly even save lives. he felt if was quite obvious that most people wouldn’t expect something like this to happen to a Mustang. A point he made was that many people including military personel who are posted overseas take their cars with them to drive on the Autobahn regularly and Ford does not sell them locally. he felt as if he did not endanger anyone except for himself. In fact, he has driven his other mustangs at speeds faster than 135MPH.

 He said that he spoke with an engineer at Ford and he inquired about the reasons behind the 113MPH speed limiter before removing it. He was told  that the 113MPH speed limiter was programmed on all of the new V6 Mustangs only because of the speed rating of the standard model’s tires. This sounds like a PR cop out statement.

His car had Z rated 149+MPH tires and he removed the limiter and just wanted to open it up. He just wished that he could use all of the power this mustang has.  He feels quite jilted now that his $33K Mustang is technically “slower then a Ford Focus” or that a Chevy Cruize Eco can do 130MPH, for $19K, according to Car and Driver.

Ford stood behind their product and repaired his car under warranty! After the damage was repaired, he said everything felt smooth again. Also, Ford flashed the ECU with an update which greatly improved the low end throttle response. Now the factory tune feels basically like the SCT did, so he is driving it stock.

I think we all would really like to see Ford upgrade the driveshaft and move up the speed limiter. Those of us who choose the V6 mustang don’t need a v8, we just want to use all of the V6 horsepower that we paid for!

8 thoughts on “The Real Story of the 3.7L Mustang Stock Driveshaft Failure

  • He is not the only one, Also these crap drive shafts have broken during drag racing and on a Dyno. It was A stupid idiot very bad design and Ford should replace all of them. What the hell were they thinking? I see that the 2013 V6 drive shafts are now aluminum and not the stupid dangerous two piece crap that is on my 2012. That stupid idiot drive shaft weighs in at 43 pounds. It uses a lot of gas and power to just get it spinning in normal driving. When you let off the gas where do you think that slight vibration is coming from? No, Someone at Ford got a nice kickback from some supplier that was stuck with these drive shafts so now us 2011/2012 Mustang owners are stuck having to buy a new drive shaft and screwing with the powertrain warranty. I sure would like to know how many of the 2011/2012 drive shafts have had to be replaced for vibrations and clunking noise.

  • I have a 2014 model, and I have the same vibration on decel and inferior 2 piece driveshaft. I have already researched a replacement that is 1 piece aluminum and about 18 lbs lighter than OE.

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