Need help!! Mantic clutch issue.

[Platinum_5.0]

So I just had a new Mantic twin disk clutch installed into my 17 GT. The clutch feels amazing. Nice pedal feel, great engagement, no noise and just a little chatter if not enough fuel give at take off. Here's the problem. On the first day everything was great. That same night, all of a sudden the gear shifter started getting stuck in gear but only when decelerating. When Accelerating and up shifting it shifts perfectly. Once I'm slowing down and down shifting the shifter gets stuck. The harder the engine is under vaccum, going down hill for example, the harder it's locked into gear. I have 2 options. I can either rev the engine up to take load off and then the shifter will come out nicely or I can wait until the RPMs drop to 1000rpm or less then the shifter comes out of gear. Any ideas as to what is going on???

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[Burkey]

When the clutch pedal is on the floor, car stationary and in first, how far do you have to lift it before the car starts to creep forward?

 

[Platinum_5.0]

When the clutch pedal is on the floor, car stationary and in first, how far do you have to lift it before the car starts to creep forward?

In that regard? About halfway. It feels just like it did stock. It now intermittently gets stuck in first gear. Stopped at a light, clutch in and shifter won't come out unless I let the clutch up off the floor just enough that I can pump it 2 or 3 times then it comes out of first. I'm convinced it's a hydraulic issue but it's been bled a few times and with the vaccum at the top. I do know that the shop didn't bench bleed the TOB. Maybe air in there? Have you ever heard of using a GM slave?

 

[Burkey]

In that regard? About halfway. It feels just like it did stock. It now intermittently gets stuck in first gear. Stopped at a light, clutch in and shifter won't come out unless I let the clutch up off the floor just enough that I can pump it 2 or 3 times then it comes out of first. I'm convinced it's a hydraulic issue but it's been bled a few times and with the vaccum at the top. I do know that the shop didn't bench bleed the TOB. Maybe air in there? Have you ever heard of using a GM slave?

Pumping the pedal to achieve pressure is certainly pretty indicative of air in the line.
Having said that, there have been cases where the TOB just seems to quit (possibly drawing air in on the return stroke?).
I had absolutely ZERO success with the vacuum method.
If you want to talk GM TOB, Timmy Anders can be found on the FB All motor Coyote page and the 2015+ page. He had the same dramas, cracked the shits and went GM TOB.
I posted pics of his setup on this forum somewhere but I don’t recall where sorry.
Best of luck with it.
Sounds like the box is coming back out again regardless...

 

[Platinum_5.0]

Pumping the pedal to achieve pressure is certainly pretty indicative of air in the line.
Having said that, there have been cases where the TOB just seems to quit (possibly drawing air in on the return stroke?).
I had absolutely ZERO success with the vacuum method.
If you want to talk GM TOB, Timmy Anders can be found on the FB All motor Coyote page and the 2015+ page. He had the same dramas, cracked the shits and went GM TOB.
I posted pics of his setup on this forum somewhere but I don’t recall where sorry.
Best of luck with it.
Sounds like the box is coming back out again regardless...

Ok thanks for your input. I'll look Timmy up. And for your bleeding method, with no success using the vaccum method, you just pump it forever? Lol

 

[Burkey]

Ok thanks for your input. I'll look Timmy up. And for your bleeding method, with no success using the vaccum method, you just pump it forever? Lol

Hell NO!
I learned the hard way. I “thought” I’d bench bled it properly the first time.
It wasn’t right.
No amount of pumping or vaccum was gonna fix it. Believe me, I spent the better part of a full day trying both methods to no avail.
As far as I can see, the design of the TOB places the fluid entry slightly below the highest point of the TOB, ergo, if there’s air in there, it isn’t gonna come out.
I tried lifting the left side of the car to raise the entry point. No good.
Removed the box and did this:
I bench bled the TOB (hard line attached) and then bled it some more, then a little more, then raised the entry point and did it some more. You’d be surprised at what comes out.
Fitted TOB and hard line to box, making sure box was rotated approx 45 degrees. Bled it again with the box in that position.
Fitted box, which obviously squeezes some fluid out as the TOB collapses.

THIS IS THE REALLY IMPORTANT PART
IF you get the box located a bit and then pull it back a bit, you’ve just squeezed fluid out and allowed air IN.....

Made sure to top-off the plastic elbow connection at the box (in case air had been allowed back in) let it sit for a moment to allow any air to rise, THEN presented the clutch line to the elbow and allowed it to dribble for a bit.
It’s messy, it’s time consuming, it’s possibly OCD, it works.
Apologies for the lengthy reply but having pulled the box 3 times, I know how much it sucks to do it more than once.

 

[db252]

While slave cylinder is always a factor to be checked and proper bleeding is a major factor, it's not the only thing going on here. I'm guessing you put in a 9000 series (organic or ceramitallic doesn't matter) and if that's is the case, it is an extremely light setup with small diameter discs and it is slowing its rotation much quicker than a stock or near stock setup. This is excellent for racing applications where off throttle is helpful in slowing the car down but not so helpful on regular street driving applications because as you decide to switch from gear to gear, while letting off the accelerator, it is already trying to slow the engine due to lack of inertia causing tension pressure between the engine and transmission with the clutch being the gateway . This is part of the problem of the resistance in the shifter coming out of gear in casual shifting. Stock or near oem replacement clutches factor this in especially for the masses of daily driving a car. Don't get me wrong; I absolutely love the Mantic clutches and have installed three of them including my car and they are all the smoothest, noiseless and soft pedal actuated I've been around and its not a small thing. I unfortunately had to change out of my Mantic when I switched to the Tremec Magnum XL with a 2.66 first gear as I needed the weight and mass to help drive that trans better.

See if slightly aggressive/exagerated(?) shifting on the street helps your situation.

 

[aleccesarenriquez]

I had this exact issue for a few months with the cerametallic one until my trans gave out. I don’t think my trans going out (3rd gear) had much to do with this, but it was annoying considering how much money the clutch is. I have the stock clutch in now on a stage 1 Ben calimer mt82 and the clutch is starting to smell pretty strong after pulls, so I’ve been on the fence about what to do. I’m hesitant to go back to a mantic considering all of the issues I was having with it. Heavily considering an rxt or an exedy et04xd, even though I know those are relentless and not particularly good for an mt82

 

[Platinum_5.0]

I had this exact issue for a few months with the cerametallic one until my trans gave out. I don’t think my trans going out (3rd gear) had much to do with this, but it was annoying considering how much money the clutch is. I have the stock clutch in now on a stage 1 Ben calimer mt82 and the clutch is starting to smell pretty strong after pulls, so I’ve been on the fence about what to do. I’m hesitant to go back to a mantic considering all of the issues I was having with it. Heavily considering an rxt or an exedy et04xd, even though I know those are relentless and not particularly good for an mt82

So I'm out of town but I'm going to take the TOB out and bench bleed it and see if it get resolved. If that don't work then I'm going to try the Mcleod adjustable slave/TOB

 

[FoMoCoMoFo16]

How did it go?

 

[Nutones]

So I'm out of town but I'm going to take the TOB out and bench bleed it and see if it get resolved. If that don't work then I'm going to try the Mcleod adjustable slave/TOB

Hey Platinum 5.0: did you ever figure out what was causing the problem and get it resolved?

 

[Platinum_5.0]

Hey Platinum 5.0: did you ever figure out what was causing the problem and get it resolved?

Well I sent the clutch back to Mantic and he checked it over and said it was working perfectly. At the same time I checked my slave and it was dead, wouldn't hold fluid at all. I put a brand new one it and re installed the clutch and it was perfect for about 4 days and now it's happening again with the shifter getting stuck. Good friend of mine is having the same issue. Getting ahold of Geoff at Mantic tomorrow and discussing my option to get a refund on the clutch or try sending me a new one to try

 

[Nutones]

Hmmm! I wonder whether the culprit could be the clutch master cylinder unit attached to the clutch pedal assembly?

 

[MacKinnon654]

Well I sent the clutch back to Mantic and he checked it over and said it was working perfectly. At the same time I checked my slave and it was dead, wouldn't hold fluid at all. I put a brand new one it and re installed the clutch and it was perfect for about 4 days and now it's happening again with the shifter getting stuck. Good friend of mine is having the same issue. Getting ahold of Geoff at Mantic tomorrow and discussing my option to get a refund on the clutch or try sending me a new one to try

What was the outcome? I'm having the same issues with mine I just installed!

 

[FoMoCoMoFo16]

You need to figure out if you're blowing up your slaves. Might need to bleed them better or possibly missing a shim behind the slave. If Geoff says the clutch itself is good it's good. He's a stand up guy and extremely helpful in my experience.

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