[Strange clutch issue] Progressively stiff pedal, can't shift above 6k rpms

[Justinjor]

I was racing over the weekend when this problem started out of nowhere.

I noticed the clutch pedal got VERY stiff after a few pumps. I thought I might have got the boiled the fluid so I let the car cool off and drove it home. The next morning I changed out the fluid with no change in the behavior.

If I'm just cruising around and shifting it below 3,000 rpms it acts fine. As soon as I bring the rpms above 3000 the problem starts up immediately. Within 2 or 3 shifts, the pedal is so stiff that I'm afraid the hydraulic line is going to explode or something.

I absolutely cannot shift the car above 6000 without being locked out until the rpms come back to 3000 or so.

Any thoughts on the issue? I'm debating taking it in for service and having the dealer fix/figure it out, or just going ahead and putting in a boss clutch since I understand they work better at higher rpms.

Thanks in advance

 

[onebadgsx]

6r80. Done....

 

[Bcalimer]

Sounds like something with the slave cylinder to me.

 

[cgibs89]

http://s197forum.com/forum/showthread.php?t=95342

The assist spring to "make it easier to disengage the clutch" likes to keep the pedal stuck to the floor on high RPM shifts. Remove it.

 

[Justinjor]

http://s197forum.com/forum/showthread.php?t=95342

The assist spring to "make it easier to disengage the clutch" likes to keep the pedal stuck to the floor on high RPM shifts. Remove it.

Assist spring was removed before the car turned 50 miles on the odometer. It's something in the hydraulics or the clutch itself I think.

 

[Justinjor]

Update to this: The problem continues but the symptoms have changed. The extremely stiff pedal seems to surface randomly and disappear just as randomly. I'm having a difficult time narrowing down the cause and do not want to take it to the dealer for them to try and figure it out.

I figure it's one of 4 things, clutch, slave cyl, master cyl, or the hydraulic line.

Any other suggestions?

 

[Bad Boss 302]

Sounds like you need the clutch hydraulic line changed out to the hi capacity line available in the after market. JPC has one.

 

[BMR Tech]

Too much nawz.

 

[Justinjor]

Too much nawz.

Nope. Issue has been going on long before that.

 

[DrTriton]

Sounds just like my '11 GT. High RPM shifts also seem like I am not getting complete disengagment - trans shifts very rough. I haven't taken my car to the dealer yet because I really don't feel like having a tech drive the hell out of it to try and replicate the problem, plus next week I'm getting the Roush Phase 3 SC kit installed - I'm sure they will blame it on that. I'm going to put a new slave cylinder and Ford Racing clutch line in it while the engine is out.

I will let you know if it improves.

 

[hawkeye18]

Have you checked to see if your pressure plate bolts are backing out?

 

[Justinjor]

Have you checked to see if your pressure plate bolts are backing out?

No. I was under the impression that issue was fixed long before the 2013s came out. Is there an easy way to check without pulling the trans? I don't remember seeing an inspection cover.

 

[86GT351]

Sounds like the Pressure Plate is going bad actually!

 

[Mountain]

Almost sounds like there is an issue with the pressure plate spring fingers. Especially since things seem worse at high RPM. The clutch itself is the one thing that can be affected by different RPM ranges.

 

[hawkeye18]

No. I was under the impression that issue was fixed long before the 2013s came out. Is there an easy way to check without pulling the trans? I don't remember seeing an inspection cover.

"Fixed", yes. Actually fixed? Questionable at best. You will have to take the trans off to check it, though.

 

[MarkyMark1082]

Justin, did you get this fixed?

 

[Justinjor]

No Mark, I didn't. It's hit or miss it seems..it hasn't done it in about 2 weeks, but before that, it would do it every time I went for a drive. It's weird, but at this point, I don't know what to do with it. I'm not going to blindly replace parts, and I don't want the dealer trying to replicate the issue(i.e., beat on the car) so for now, I'm just dealing.

 

[MarkyMark1082]

That sucks bro. Good luck man.

 

[ryan]

I had the same issue (high RPM shifts were impossible) for a while on my '11 GT. I brought it in several times and each time they told me it was something different (the first time, they told me my floor mats were preventing the clutch pedal from being pressed all the way - gotta love that). Eventually, they replaced my clutch. That was at 20k miles. Now I have 50k and it's starting all over. I wouldn't say I baby the car, but I certainly know how to drive it properly. I believe there is a design flaw in the clutch assembly. New parts only push back the about of time the defect rears it's ugly head. I think I'll be going aftermarket when this clutch fails.

my 2 cents

 

[Justinjor]

Ya I think it's a clutch issue. I expect to be putting in an aftermarket clutch pretty soon. I've just about had enough.