Ford Mustang Forum banner
1 - 20 of 29 Posts

minininja

· Registered
2007 Mustang GT, 4.6L, RWD
Joined
·
17 Posts
Reaction score
3
Location
Helena, MT, USA
Discussion starter · #1 ·
Ok guys here is my situation. I was driving casually into town when my clutch started working less and less until nothing. I have an exedy stage 4 clutch in there with less then 1k miles on it. I can rev match to shift just fine so I think the syncros are fine but I'm not 100% certain as I don't have much experience working with manual transmissions. Additionally the clutch does not slip at all I stomp on it starting at 3k moving up to 6k rpm and it holds steady all the way though.

I tried a new slave cylinder and added a spacer in because before my clutch disengaged with the petal almost fully to the floor. I noticed when I pulled the hydraulic line off the slave that almost no fluid came out. That lead me to believe that maybe there is an issue with the clutch master cylinder so I replaced that and still nothing.

I can see that the slave is moving as it should when pushing the clutch in. It presses into the pressure plate springs however I'm not 100% certain it is pressing it in far enough, but it is most definitely making contact with the pressure plate springs and moving them inwards towards the engine.

Anybody have any ideas where I might go from here? Honestly at this point I'm at a complete loss and have no idea where to look next.
 
That's weird with a new clutch. I've had the same issue with my car since I bought it in 2020. Driving around town at low rpm I can shift as fast I want. Up around 6,000rpm I have to clutch in and wait, between shifts because it just locks out and prevents the shift.

In my case, I did everything except the clutch / slave and nothing has fixed the problem.

  • Braided line
  • CHE torque limiter
  • MGW Flat stick
  • Amp bronze bushings
  • M1 ATF
  • New powertorque clutch master cylinder
  • Blowfish V2 bracket

I'm almost convinced with my setup (and possibly yours) that the clutch hydraulic system just doesn't allow for enough travel to disengage fully. My clutch still grabs super hard so it's not dead but at the same time I guess it's worn down enough to not allow full disengagement.

How thick of a shim did you put in? And would it be possible to get a video looking through the bellhousing inspection hole while someone operates the clutch?
 
Discussion starter · #3 ·
That was my original though as the slave wasn't quite pushing far enough to disengage the clutch. That is why I added the spacer and replaced the slave, that spacer didn't give me any clutch disengagement though so that's why I went after the master cylinder. I'm not sure what else could be causing the clutch to not fully disengage. The shim/spacer was 0.156", figured I would go with a smaller spacer considering the clutch worked fine for the first 1,000ish miles before it stopped working.
 
Can you shift without the clutch? Obviously launch with it but you should be able to slip it in gear round 2,250-2,400rpm (at least on my car) without the clutch and without any grinding.

I actually did that same test with my car trying to figure out if it was clutch or synchro's. I can shift from 1st to 5th without the clutch and then from 5th back to 1st without the clutch and no grinding.
 
Discussion starter · #13 · (Edited)
Maybe slightly on the squishy side like there could still be a tiny amount of air in the lines. However it certainly doesn't feel like it's anywhere near bad enough to not work. It does however have a decent amount of free travel, additionally the slave probably have close to 3/8" gab between the end of the slave the the pressure plate. Not sure what the actual spec is for clutch pedal free travel on those though.

I felt like with the clutch working for the first little while with adding in that spacer even though it was fairly small, it should have brought back the clutch.
 
Discussion starter · #15 ·
Ok so it looks like you already have your pressure plate loaded a tiny amount. I guess I will order a bigger spacer and see what that turns up. It's strange though that it worked before with no spacer in there. Maybe this next time I will pop the clutch off and see how it looks before I throw it all together. Thank you very much for all your help thus far! I will post an update after I get the spacer and find the time to throw it in.
 
I bled it again after replacing the slave and the master cylinder. That's why I'm so confused right now.
Did you gravity bleed it or try to pump bleed it like the brakes? You have to gravity bleed the clutch.
 
Discussion starter · #19 ·
I bench bled the slave before I put it in then gravity bled the rest of the system. Also I put a new flywheel in when I did the clutch. Still waiting on my spacer to ship unfortunately, but I think a larger spacer to clear up that gap between the slave and the pressure plate is the next place to go.
 
Just for reference and if its not too much trouble, can we get a video looking through that inspection hole on the bottom of the trans? I'm curious to see how much gap there actually is.

It seems insane to me that even with a 0.156 shim, you are still so far away... What kind of a setup did you originally take out? Did it have a shim behind the slave cylinder?
 
1 - 20 of 29 Posts