tevaburns

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Somebody asked on a different thread if the folks with that 'affliction' replaced/removed the stock spring. I'm hoping the answer is yes, meaning those of us with stock spring, will never experience that failure :). As a final note, is there anything we could lube to minimize the stress on that area? It didn't look possible to spray anything in that bushing with everything in place, but hope to be wrong.
My clutch pedal broke at 14,000 miles, I had the steeda spring in. I bet all of our pedals will fail at the welds... It's only a matter of time.
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Brian@BMVK

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Somebody asked on a different thread if the folks with that 'affliction' replaced/removed the stock spring. I'm hoping the answer is yes, meaning those of us with stock spring, will never experience that failure :). As a final note, is there anything we could lube to minimize the stress on that area? It didn't look possible to spray anything in that bushing with everything in place, but hope to be wrong.
There's nothing that supports the idea that the assist spring tension would prevent or prolong this failure. The force to compress the MC plunger is the same in total, but the assist spring just changes how much comes from your foot. The tensile and torsional forces about the pivot, and bending forces in the pedal beam don't change. The reaction force of the assist spring is resolved in the plastic structure of the pedal assembly.
 

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I understand what you're saying, but there are other factors. The spring is exerting the force higher up in the pedal stem, so that leaves the force needed at the pedal LESS than without spring. You should be with me up to now, since it's just physics 101 :). Now we know that with a longer lever, any force applied to the pedal will be higher without the stock spring, and that could be the problem if you apply any of the force in a vector, meaning applying some of the force to depress the pedal sideways. That is probably what is breaking the metal right above the weld (it's NOT the weld that fails). So that's my take. The spring is applying the pressure to the pedal dead straight, so the remaining force needed to depress the pedal, even if applied slightly sideways, it's not enough to break the metal. But the higher force needed without the spring, might be enough to do so. So I think it's absolutely possible the failures are due to removing the stock spring. How many clutch pedal failures have you heard of on stock cars??? If all failures have no spring or Steeda spring, would you attribute that to chance? I don't think so. Ha ha. So let's hear from them :).

FInally, I'm not giving Ford a pass by any means, since they shouldn't be doing the designing components at the very edge of the minimum strength needed. But I also have to point out there are manual Mustangs with close to 100K miles and more with no clutch pedal issues, so it's important to see if we can find a trend.
 
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Brian@BMVK

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I understand what you're saying, but there are other factors. The spring is exerting the force higher up in the pedal stem, so that leaves the force needed at the pedal LESS than without spring. You should be with me up to now, since it's just physics 101 :). Now we know that with a longer lever, any force applied to the pedal will be higher without the stock spring, and that could be the problem if you apply any of the force in a vector, meaning applying some of the force to depress the pedal sideways. That is probably what is breaking the metal right above the weld (it's NOT the weld that fails). So that's my take. The spring is applying the pressure to the pedal dead straight, so the remaining force needed to depress the pedal, even if applied slightly sideways, it's not enough to break the metal. But the higher force needed without the spring, might be enough to do so. So I think it's absolutely possible the failures are due to removing the stock spring. How many clutch pedal failures have you heard of on stock cars??? If all failures have no spring or Steeda spring, would you attribute that to chance? I don't think so. Ha ha. So let's hear from them :).

FInally, I'm not giving Ford a pass by any means, since they shouldn't be doing the designing components at the very edge of the minimum strength needed. But I also have to point out there are manual Mustangs with close to 100K miles and more with no clutch pedal issues, so it's important to see if we can find a trend.
Do the FBD
 

Porsche_Manny

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Great thread — I bought my '17 GT used end of Jan. 2020. It had 11,500 and it now has $49,500 (commute 100 miles a day).

The previous owner put in a Steeda clutch spring, which I found out when I ordered one — and went to replace it and found the very same spring already installed. 🙃

That said, my clutch pedal began creaking at 45,000-46,000 miles.

https://www.dropbox.com/s/ifarbwhy5i4px7y/VID_93250801_025325_045.mp4?dl=0

Tried greasing pivot points, etc etc, and then checked on here to find the damn pedals actually cracked!

I'm a Porsche tech, so after fixing German craziness all day, I got this car because my Dad had 3 SN95s and they never really went wrong. Was surprised to find something as important as the clutch pedal to be skimmed on — or at least built to such fine/minimal tolerance.

My pedal never finished failing, I wasn't going to wait until it failed on my 2 hr commute.

Pedal -was- cracked on where they seem to always fail.

I assume my new pedal assembly is near the newest production. It's much softer with the latest OEM spring, kind of Honda like in effort.

I guess this is the pedal force the assembly was originally designed to handle? Or they've put even stronger springs in to reduce pedal force (instead of making stronger welds)?

I prefer a heavier clutch pedal, and was tempted to Steeda Spring it again — but I prefer an unbroken clutch pedal even more.
 
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I prefer a heavier clutch pedal, and was tempted to Steeda Spring it again — but I prefer an unbroken clutch pedal even more.
There is no evidence nor engineering proof that the lighter spring causes or exacerbates this. In fact, I personally conversed with the design engineer for the 2015MY S550 pedals about the spring forces. The high rate spring was chosen purely to reduce pedal efforts for a broad customer base (including EU). The total force balance shows that the rate of the spring has zero effect on net forces at the welds.

Issue: poor manufacturing quality of welds on pedal + low design margin for manufacturing variation = failures on some cars.
 

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There is no evidence nor engineering proof that the lighter spring causes or exacerbates this. In fact, I personally conversed with the design engineer for the 2015MY S550 pedals about the spring forces. The high rate spring was chosen purely to reduce pedal efforts for a broad customer base (including EU). The total force balance shows that the rate of the spring has zero effect on net forces at the welds.

Issue: poor manufacturing quality of welds on pedal + low design margin for manufacturing variation = failures on some cars.
You went in deep if you got to the engineer, thanks. How many miles have you gone with the new pedals if you put the Steeda spring in your new clutch pedal?
 

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...other Nissans like the S14s, NISMO actually sold clutch bracket reinforcements lol. Such cost-cutting BS.
I wish I had known about that when the clutch bracket broke in my S14.
When I got a new clutch bracket, I was surprised to see it hadn't changed at all from the old POS.

I sketched it, and showed it to my little sister (who was still in high school). I asked "If this breaks, where do you think it will be?"
She pointed to the sharp corner, right where the old one had broken.
So my sister with no education relevant to this, and I with my engineering degree, both thought it was obvious where the part was weak.
[This is where a professor would say "It's intuitively obvious to the most casual observer."]

The engineers clearly could have designed a better part, but probably lost an argument to the bean counters. Why use a $1.00 bracket when a $0.50 part will be enough for most users?
 
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cmxPPL219

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I wish I had known about that when the clutch bracket broke in my S14.
When I got a new clutch bracket, I was surprised to see it hadn't changed at all from the old POS.

I sketched it, and showed it to my little sister (who was still in high school). I asked "If this breaks, where do you think it will be?"
She pointed to the sharp corner, right where the old one had broken.
So my sister with no education relevant to this, and I with my engineering degree, both thought it was obvious where the part was weak.

The engineers clearly could have designed a better part, but probably lost an argument to the bean counters. Why use a $1.00 bracket when a $0.50 part will be enough for most users?
Great story about your little sister!

But yes, this cost-cutting is so penny-wise, pound-foolish in the car industry, it often leads to recalls as we have seen, across the whole industry, and they just never learn.
 

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Yikes, I have 2015 model with 95,xxx miles and a while back I noticed my clutch pedal would squeak sometimes. I sprayed some lubricate and the noise went away. Probably be best to replace my assembly before it completely falls apart. :shock:

JR3Z-2455-A still the part number or is that for 18+ vehicles?
 

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Yikes, I have 2015 model with 95,xxx miles and a while back I noticed my clutch pedal would squeak sometimes. I sprayed some lubricate and the noise went away. Probably be best to replace my assembly before it completely falls apart. :shock:

JR3Z-2455-A still the part number or is that for 18+ vehicles?
You're in for the biggest pita install. Just know that. Make sure you remove the sunglass holder, unbolt the obd2 port, and remove the clutch master cylinder first. That will make it about as easy as it can possibly get. Oh, and please remove the driver's seat.
 

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Anything else I should order while I'm there replacing the clutch pedal assembly?
There is a light blue clevis that will need replaced as well. For some reason it is sold separately. The assembly comes with a new clutch master cylinder so you're good there.
You'll need a turkey baster or something like it to remove the fluid from the brake master cylinder. I taped a straw inside of mine to get all the way in there and remove as much fluid as possible.

After the install, you'll want to use a Mighty Vac and rubber stopper to properly bleed the clutch and remove any air. It works so much better than just pumping the pedal a thousand times.
 
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