2016 Mustang GT shuddering

Studdering while slipping is usually caused by hard spots on the fly wheel due to excessive slipping the clutch. The metal superheats and becomes harder and slippery so the clutch is sliding over these spots unevenly.

OP's clutch probably had some rough life during break in. New clutch and fly wheels have high and low spots so excessive slipping the clutch can super heat those spots before they get worn down to a smooth and even finish.

UglyMutt said:

Sounds like you glazed the clutch and are getting some chatter from it not hooking up. Are you getting any clutch slip?

Click to expand...

I haven't experienced any slipping other than when operating the clutch pedal as intended. Unless it is slipping just a little bit more than what it should for the pedal position. Then locking up later. Maybe that is why it seems to grab so suddenly at the end of engagement? Is there a way to tell / measure? Anything that can be done to rectify without removal?

It would be interesting to see if there are any discolorations on my clutch disc/plate/flywheel, but not worth the effort to take it apart unless it has already failed. I wonder if a bore scope could fit up in there ...

With regard to hot spots, anything is possible, but I didn't go through the learning curve with excessive slipping (not my first manual) and my casual daily driving launches generally has the RPM between 1,000 and 1,500 rpm and only last a few moments. Spirited launches are far and few between and I don't track at all.

I can't imagine a way to be nicer to a clutch or I would be doing it already.

I can tolerate the quirkiness so long as it isn't an indicator of a more serious problem that needs repair before it becomes a catastrophe...

Grimmer said:

How much free play is there supposed to be in the clutch pedal? I've always felt that mine disengages too close to the top. It is almost immediate when pressing the clutch pedal. Worst still, it seems to me that the helper spring cams over about 2/3 of the way through the re-engagement creating an uneven and nearly uncontrollable finish to engaging the clutch. I've also been concerned that the throw-out bearing isn't getting fully released.

Click to expand...

Sounds like you need to replace the super stiff OEM helper spring with the softer Steeda helper spring. Makes clutch pedal modulation much more even feeling.

Grimmer said:

I haven't experienced any slipping other than when operating the clutch pedal as intended. Unless it is slipping just a little bit more than what it should for the pedal position. Then locking up later. Maybe that is why it seems to grab so suddenly at the end of engagement? Is there a way to tell / measure? Anything that can be done to rectify without removal?

It would be interesting to see if there are any discolorations on my clutch disc/plate/flywheel, but not worth the effort to take it apart unless it has already failed. I wonder if a bore scope could fit up in there ...

With regard to hot spots, anything is possible, but I didn't go through the learning curve with excessive slipping (not my first manual) and my casual daily driving launches generally has the RPM between 1,000 and 1,500 rpm and only last a few moments. Spirited launches are far and few between and I don't track at all.

I can't imagine a way to be nicer to a clutch or I would be doing it already.

I can tolerate the quirkiness so long as it isn't an indicator of a more serious problem that needs repair before it becomes a catastrophe...

Click to expand...

It could be also manufacturing defect. Maybe the flywheel was never truly flat from the factory.

I also wondered about the 118 miles that were on the clock when I picked it up. It had been on the other dealer's showroom floor for 5 or 6 months before transferring to my dealer for me. Quite a few test drives and probably the office staff cruising a little. Every salesman at every dealership I visited to test drive while comparing options told me the same thing... "feel free to put the hammer down".

Maybe the clutch got ruffed up at that time, or maybe manufacturing defect... Either way virtually impossible to convince them to replace a clutch under warranty.

GT Pony said:

Sounds like you need to replace the super stiff OEM helper spring with the softer Steeda helper spring. Makes clutch pedal modulation much more even feeling.

Click to expand...

I have... Or at least I did for a while until it bugged me enough to mention to the dealer shop, then I swapped it back so they wouldn't try to blame the aftermarket spring for the problems...

Now that the PP2 has been installed I have put back the Steeda spring. We'll see if the combination of the PP2 throttle mapping and softer spring make a difference. That's also why I was wondering about the free play. I've thought about loosening the clutch a tiny bit to get the cam over point to shift to outside the clutch engagement zone.

Just drive it till it goes and put in a Mantic. That's my plan.

Grimmer said:

I also wondered about the 118 miles that were on the clock when I picked it up. It had been on the other dealer's showroom floor for 5 or 6 months before transferring to my dealer for me. Quite a few test drives and probably the office staff cruising a little. Every salesman at every dealership I visited to test drive while comparing options told me the same thing... "feel free to put the hammer down".

Maybe the clutch got ruffed up at that time, or maybe manufacturing defect... Either way virtually impossible to convince them to replace a clutch under warranty.

Click to expand...

I'll make you feel better, mine had 394 dealer transfer miles upon purchase.

Kong76 said:

I'll make you feel better, mine had 394 dealer transfer miles upon purchase.

Click to expand...

Yeah, I even asked them before we transferred it whether or not it was just sitting on the lot or if the dealership had been driving it around town. They "assured" me that it was just a lot car...

There was only one that fit my requirements within all the surrounding states. So the only other choice was to order it from the factory which would have wasted the whole summer driving season. A guy at our office ordered his Challenger and at the end of the 6-8 weeks build time it failed the QC checks and was delayed another 4 weeks at least.

Kong76 said:

Just drive it till it goes and put in a Mantic. That's my plan.

Click to expand...

My plan too. Drive it till it fails and put in something better.

UglyMutt said:

Sounds like you glazed the clutch and are getting some chatter from it not hooking up. Are you getting any clutch slip?

Click to expand...

Grimmer said:

I haven't experienced any slipping other than when operating the clutch pedal as intended. Unless it is slipping just a little bit more than what it should for the pedal position. Then locking up later. Maybe that is why it seems to grab so suddenly at the end of engagement? Is there a way to tell / measure? Anything that can be done to rectify without removal?

It would be interesting to see if there are any discolorations on my clutch disc/plate/flywheel, but not worth the effort to take it apart unless it has already failed. I wonder if a bore scope could fit up in there ...

With regard to hot spots, anything is possible, but I didn't go through the learning curve with excessive slipping (not my first manual) and my casual daily driving launches generally has the RPM between 1,000 and 1,500 rpm and only last a few moments. Spirited launches are far and few between and I don't track at all.

I can't imagine a way to be nicer to a clutch or I would be doing it already.

I can tolerate the quirkiness so long as it isn't an indicator of a more serious problem that needs repair before it becomes a catastrophe...

Click to expand...

I have been thinking more about your question. One thing sticks in the back on my mind... Every once in a while when down shifting and hammering on it (e.g. quick passing on the freeway), I have experienced a delayed lock up on the clutch. I have previously assumed that it was pilot error and that I was simply jumping the gun on the throttle while at the same time being a little too slow engaging the clutch. I.e. any slipping was related to my pressure on the clutch pedal.

Now I want to put that to the test. The next time it happens (or if I can induce it to happen), I'll try dumping the clutch the rest of the way while still on the throttle to see if the slipping follows my foot pressure on clutch pedal, or if it is indeed slipping without operator input.

At the end of the day, is there anything that I can do (aside from driving technique) to correct the slipping without tearing it apart? Anything that can be done to remove any glazing? Or at least prevent it from making itself worse?

And finally, is there any chance of convincing the dealership / Ford that it was an inherent problem since I took delivery and getting it repaired under warranty? Or will it be the same old "clutch is a wear part" routine?

Something to check. I saw a post about a connection on the master cylinder that feeds the clutch. The connection is a black plastic connection, on the fender side of the master cylinder, toward the bottom. The plastic hose isn't seated properly and it appears to be a common issue. The hose is also too short and is probably why it's loose.

I resecured the hose and my shifts are much smoother. I thought it was all in my head until my son drove the car and said he noticed that the shifting is much smoother now.

My car's issue is similar to what Grimmer states, but also a bit different.

Occasionally, and typically only in 2nd gear, I will downshift to 2nd and slowly roll in the throttle only to have the car do some serious "hiccupping". It feels like the engine is starved for fuel and/or the clutch is slipping and is rectified if I floor the throttle. My foot is completely off the clutch pedal and I'm gently rolling into the gas. The only consistency is that it only happens when in 2nd gear.
I've had many, many manual transmission cars, so this isn't some newbie problem. I have driven the car fairly hard, but not any harder than any of my other manual Mustangs that never had clutch issues.
I'm thinking the flywheel or some weird electrical gremlin. It's still under warranty, but it's such a pain dealing with the dealer.
Thoughts?
Thanks!

I wonder if the ECU modifies throttle response when it thinks the clutch pedal is pushed? Any chance the "clutch is pushed" switch is improperly positioned and is making intermittent contact when your foot is off the pedal?

Grimmer said:

I wonder if the ECU modifies throttle response when it thinks the clutch pedal is pushed? Any chance the "clutch is pushed" switch is improperly positioned and is making intermittent contact when your foot is off the pedal?

Click to expand...

Too many electronics!! I'll fiddle around with things under the dash and see what happens. Thanks for the idea.