How many people have have the slave cylinder fail?

[TheLion70x77]

Just this past Monday I had the clutch hydraulics let go on my 2016 PP GT. It's at the dealer and deemed a warranty covered repair under my 100k/7yr Ford Certified Used Power Train Extended warranty thankfully. The master tech is still tearing into it but suspects (as do I) the slave cylinder let go as he couldn't find any issues with the lines or the master cylinder down at the pedal.

Anyone else have similar issues? I've been scavenging posts on clutch failures for 2011-2017 MY (2018+'s have a twin disc clutch and dual mass flywheel) and it seems the slave cylinder is a common failure point, either that or the clutch disc shreds at low mileage. I've noticed absolutely no issues with slip or any clutch engagement symptoms (no chatter etc.) other than the pedal sticking back when I first got it a few times (when it was stock) at higher RPM's. As I drove the car more that issue seemed to go away.

I know the common fix is an after market clutch. But I've heard rumors that Ford revised the clutch for 2017 MY despite the car overall being nearly the same as it wasn't a re-fresh year. Can anyone confirm this or have PN's? I might bright that up to the dealer in case there is a revised part. Aftermarket would be nice, but I can't justify it right now since it's still a warranty repair. No reason the hydraulic system should let go at 30k period.

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[Jetnoise]

Using factory pedal spring?

 

[Kong76]

I had my tob, pilot bearing replaced under warranty at 19k miles. Told me the clutch had half life and if I wanted to replace it. I paid $540 for new oem clutch and flywheel. All new parts going to be awesome. Nope! clutch chatters and have vibes through pedal at 1500 rpms during disengagement even after 10k miles on it. Dealer acknowledges it but won't touch it. Said its documented. I wouldn't say my slave cylinder failed but it was making a high pitch whirring sound. If I had it to do over again I would have a dedicated clutch repair shop install an aftermarket clutch. These OEM clutches are made in Turkey and they suck. Far as I know the 17' clutches are the same.

 

[TheLion70x77]

Finally got the some info on what they found. Clutch plates literally fell off. Looks like the typical POS Ford clutch pad de-lamination failure I've seen several people experience. Surprisingly to me, it wasn't the slave, so I'm footing the bill because none of the main stream auto makers cover clutch disc failures regardless of whose fault it is.

I'm seriously contemplating dropping in a Mantic 9000 organgic unit (M924236-WB) and using the Ford OE slave cylinder which it is my understanding it's intended to be used with. I really would like a lightweight unit that minimizes MOI and is more reliable at high RPMs.

I had issues with the pedal sticking to the floor even when bone stock during high RPM shifting with the stock pedal assist spring on several occasions. When I tried the steeda pedal spring it did it constantly instead of occasionally so I returned it to stock within a few days after trying the steeda unit and have run the stocker ever since.

Looking at this: https://www.lethalperformance.com/m...box-2011-2017-ford-mustang-5-0l-boss-302.html

Any experience with Mantic? I want to keep a sprung center hub and I'd really like to go dual disk to avoid an overly heavy pedal and on/off switch like engagement that most higher capacity after market single disk clutches have.

I don't want to go with a physically larger 10.5" unit either to keep MOI minimized. The budget option would be the RAM Dual Disk Force 9.5 which is also a lower mass setup, dual disk, but only has a single sprung hub which is a bit concerning for me for drive train durability and noise.

Looks like Spec also makes a dual disk dampened clutch / flywheel setup: SPC-SF50SST-2

 

[TheLion70x77]

Ended up putting down $1,500 for a Mantic 9000 white box. All the hardware sans the slave which is fine. It's a 9" unit that is lightweight in all the right places, focusing on minimizing total mass and keeping the mass as close to the center of the clutch assembly and flywheel as possible.

Ford Performance did some work on the Voodoo 5.2 and it's 215 mm (8.5 in) clutch to minimize the effects of rotating mass and allow for quicker acceleration. If memory serves correctly, between the engine, clutch and flywheel they were able to shave 18 lbs of effective rotating mass over the regular GT. Some of that was accomplished by packing the mass closer in, some of it was accomplished by lightening parts.

After all, rotating mass dampens acceleration rates. It's power that's already there that's being poorly used for it's intended purposes, which is to accelerate the car as quickly as possible. If the Mustang was as light as a Formula car (about 1600lbs with driver, no fuel), even with the stock 435 hp and horridly anemic factory tune, it would out accelerate most cars out there, with a power to weight ratio of just 3.6 lbs per hp!

All rotating masses ARE flywheels. While I wasn't planning on throwing in a new clutch any time soon due to the cost and having just spend $1400 on a new set of Pilot Sport 4S's for summer, the stock unit failed miserably and it's not a warranty part, so it's time to improve performance while also getting the car back up and running. It's all about efficiency and reliability!

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