Gene K

I reported this before. I did a little experimenting to find a way to replicate without getting thrown in jail for terrorizing a Ford Service Tech.

I have a new 2011 5.0 Mustang GT with the Manual 6-Speed. Im having a clutch issue. The clutch is sticking to the floor during high rpm shifts.

Experimenting to reproduce the symptoms resulted in the following:
1. Reving the engine out of gear with clutch in results in no issue.
2. Reving the engine in gear with clutch on floor results in stuck clutch.
3. Reving the engine in gear with clutch 1-2" off the floor results in pedal beginning to get light around 6000 rpm and being sucked to floor at 6500 rpm.
4. Putting trans in neutral while retaining 6500+ rpm with stuck clutch results in clutch pedal remaining stuck.
5. It takes significant effort to pull clutch pedal up to the point it "pops" up when its stuck if you maintain 6500+ rpm in neutral.
6. If you let off the throttle the clutch will pop up between 6500 rpm and 4000 rpm on its on. It seems "more stuck" sometimes than others.

Tried bleeding the old fashioned way (Drivers side front raised 10" with cap off and slow cycles of the clutch pedal for 20 minutes). Didnt seem to help.

Is this a faulty pressure plate? It feels like its over-centering.

Local Ford Tech's Response, "Ford probably made it that way as a safety measure".

Needless to say Im now looking for a tech at another dealer.

stangfoeva

Yeah definitely take it to another dealer that guy was no help lol. Good luck

GRABOID

"Safety measure" of what?

PTRocks

It does sound like it's over-centering. I can't figure out why there's difference between the car being in gear or neutral though.

PTRocks

It's the Days of Thunder "I'm scared of driving fast so I'll blow my motor" safety feature.

bob

Hmmmm.... sounds like the diaphragm is having problems with the engines high rev speed. Might also have something to do with the dual mass flywheel??????

Does anybody remeber hearing any problems with the dual mass flywheels in the 3rd gen F- cars or Corvette?

jeff s

Either way, the clutch isn't working propperly and should be an obvious warranty claim.

dragstart

So much for those seven grand power shifts I was looking forward to.

lp9820

Now excuse me if I am completely mistaking, but going by what I know of manual transmissions if the the clutch pedal it self is sticking to the floor and considering how the throwout bearing is incorporated into the slave cylinder then wouldn't the issue have to be isolated to the hydraulic system(clutch master cylinder or slave cylinder) or the pressure plate?

Ronn

Camaro owners are reporting problems with their pedals also. Their getting burnt smell inside their car from the clutch slipping as they are driving around. Ron

assasinator

i have no issues with my clutch of any kind.

GottaHaveIt

Almost sounds like a new form of a REV limiter ?

Gene K

The primary symptoms that makes me think its overcentering are the following.

Push the clutch in to 1-2" above floor while in gear. Rev engine past 6000 rpm and the pressure on the clutch pedal starts to reduce until at 6500 rpm the clutch pedal is "sucked" from your foot to the floor. Once this happens you can put the trans in neutral (while holding rpm at 6500 rpm plus) and keep pulling the pedal up a couple inches off the floor against the tension and the pedal will keep slamming back to the floor every time you let go. You can feel the break-over when it goes past center.

Definition of Overcentering:
Overcentering is when the diaphragm spring’s fingers get pushed past the normal centerline of the diaphragm spring. When this occurs, centrifugal force acting on the weights and diaphragm spring keeps the fingers of the spring bent down causing the clutch to stay disengaged during high RPM shifts. Overcentering can occur with any diaphragm clutch but centrifugal assisted clutches are especially sensitive to this. If you can feel the pedal get lighter with increasing revs, that is the clutch wanting to overcenter. All diaphragm-type clutches are prone to overcenter to some degree.

Im thinking either something is out of tolerance or the diaphragm spring is defective but then Im far from an expert.

Gene K

Its not new. Diaphragm clutches had this issue at high rpm when they were introduced.

GottaHaveIt

That's why "she" stops working

Gene K

Its not new. Diaphragm clutches have had this issue since day one. However I thought it had been tamed in production clutches.

GottaHaveIt

Sorry I was being a ****: what I was getting at
A Diaphragm is a thin rubber dome, Female kind

Stinger1982

that dealer is a crack pot.

That is not correct.

Find a new dealer ASAP

Gene K

I did.

BTW Just in case you think Ford doesnt read these forums....

I was contacted by a Ford Powertrain Engineer (about this post). He is sending parts to try on my car.

PS You didnt have anything to do with that did you Shaun?

coffeejolts

I like Ford more and more these days.