Centerforce clutch pedal feel?

[3836bbl]

So I replaced the worn-out Hayes street/strip in my 23 spline a833 recently.
I went with the Centerforce dual friction setup,with their throwout bearing,and had the flywheel resurfaced.I replaced the clutch cover bolts and flywheel bolts with new from Brewers Performance as well.
As per Centerforce instructions I removed the "over center spring" from under the dash.
A couple of questions,

1. How long should I drive around town easy before I take it to the track for tnt ?

2. My clutch feels real "touchy" now.Is that normal?I feel like I'm having to learn how to let out the clutch now.(the old one was as smooth as butter since the pressure plate was worn-out.

3. Since I removed the "over center spring", the clutch pedal does not come up and stay at the top,there is a little bit of pedal play.
Do I need a little spring for this under the dash?Or not worry about it?

Thanks for any advise I might get.
John

 

[sixgunrunner68]

Ok, here it is. I'm running a dual friction Center Force too.
1. 500 miles are the recommended break in period by Centerforce. Take it for what it's worth. I didn't go racing in the first 500 but I wouln't say I didn't lay into it either.

2. The diaprhram style pressure plate will have a different feel, no doubt. You'll get used to it.

3. Removal of the over center spring is necessary. If anything, it's to aid in pedal return. You're going to want about a half to three quarter inch of free play on the top. Personal preference will determine which. Check your adjustment. You don't want the clutch engaging right off the floor, especially in perf. apps. This may be why you say it feels "touchy".
No need for a auxillary return spring under the dash.

 

[moparchris]

Re:

Ok, here it is. I'm running a dual friction Center Force too.
1. 500 miles are the recommended break in period by Centerforce. Take it for what it's worth. I didn't go racing in the first 500 but I wouln't say I didn't lay into it either.

2. The diaprhram style pressure plate will have a different feel, no doubt. You'll get used to it.

3. Removal of the over center spring is necessary. If anything, it's to aid in pedal return. You're going to want about a half to three quarter inch of free play on the top. Personal preference will determine which. Check your adjustment. You don't want the clutch engaging right off the floor, especially in perf. apps. This may be why you say it feels "touchy".
No need for a auxillary return spring under the dash.

X2

 

[A31PKG]

I may be wrong here, but the over-center spring actually acts as a sort of "power assist" when depressing the clutch pedal. From my experience, the diaphram style pressure plate usually (not always) requires less pedal effort than the O.E. 3-finger (somtimes referred to as Borg & Beck) style. Consequently, with the over center spring in place, it (the spring) can overcome the pressure plate's ability to "push" the pedal back up. For this reason, the manufacturer suggests removing it to minimize this possibilty. Over the last couple of decades or so the diaphram style clutch has been adopted for passenger cars because of the smooth and easier pedal effort it provides, while providing above average clamping force. Further, the above is not an issue with a modern diaphram clutch due to the introduction of hydraulic clutch master & slave cylinders. With regards to our Road Runners (and likely all manual trans cars of the era) the geometry of the pedal, z-bar, linkage, etc is simply not designed for a diaphram style clutch IMO. I think the engineers were aware of the heavy-duty nature of the 3-finger clutch, and realized that the pedal effort may be a bit much, so they installed the over the center spring to help the clutch "feel" lighter. If your spring is removed and the pedal is staying on the floor, this could be a contributing factor. Of course hopefully there is nothing else amiss with the set-up, such as binding components, etc.

If I'm blowin' smoke somebody jump in.....

 

[sixgunrunner68]

If I'm blowin' smoke somebody jump in..... [/quote]

Not blowing smoke.
That's exactly why it needs to be removed.

 

[moparchris]

I may be wrong here, but the over-center spring actually acts as a sort of "power assist" when depressing the clutch pedal. From my experience, the diaphram style pressure plate usually (not always) requires less pedal effort than the O.E. 3-finger (somtimes referred to as Borg & Beck) style. Consequently, with the over center spring in place, it (the spring) can overcome the pressure plate's ability to "push" the pedal back up. For this reason, the manufacturer suggests removing it to minimize this possibilty. Over the last couple of decades or so the diaphram style clutch has been adopted for passenger cars because of the smooth and easier pedal effort it provides, while providing above average clamping force. Further, the above is not an issue with a modern diaphram clutch due to the introduction of hydraulic clutch master & slave cylinders. With regards to our Road Runners (and likely all manual trans cars of the era) the geometry of the pedal, z-bar, linkage, etc is simply not designed for a diaphram style clutch IMO. I think the engineers were aware of the heavy-duty nature of the 3-finger clutch, and realized that the pedal effort may be a bit much, so they installed the over the center spring to help the clutch "feel" lighter. If your spring is removed and the pedal is staying on the floor, this could be a contributing factor. Of course hopefully there is nothing else amiss with the set-up, such as binding components, etc.

If I'm blowin' smoke somebody jump in.....

I think I hear what your getting at. I have found that my cars shift way better and have better holding power with a long style (3 finger).

 

[SomeCarGuy]

The adjustment is wrong. Adjust it some more and the pedal will start returning properly.

I've run several of those clutches. I would describe them as more "all or nothing" than touchy. Might just need the adjustment and the full break in to occur.

 

[3836bbl]

Tonight,I put in the little rubber pedal stop for the clutch that I had a buddy pick up for me @ the Nats.(what a joke these stops are,thin piece of rubber made for silencing armature at rest,at best)
I adjusted the clutch pedal for 3/4 inch travel.
I was way off on the adjustment(I had a lot more travel)
Clutch no longer lets off at the floor,more like 1/2 to 5/8 off floor.
pedal comes most of the way up(within 3/8 in of the brake pedal.
All or nothing describes the way my clutch lets out.
We'll see how it behaves after a few days of driving around town with occasional break-in periods(burnouts)
John

 

[SomeCarGuy]

You need a torque strap. Chain or the nice but spendy Schemaker setup.

New bushing kit for the Z bar.

No overcenter spring.

Pedal should reurn ALL the way to the top when adjusted correctly. Even w/o a strap, it will still work, just might not like power shifting.

When you push in the pedal, it should go 1.5-2 inches then you will find the diaphram with the TOB. Then you will feel it collapse as you go farther. When you let off, it should return ALL THE WAY TO THE TOP. I mean bang the stop return.

Be sure to use a new nylon nut or better yet TWO nuts. A jam nut setup if you will.

The pedal will have a feel about 50% where you will really feel the diaphram "pop".

A good way to see this is to have a helper work the clutch whiel you are under there watching. Ask where the pedal is when the TOB is all the way back, when it is just against the diaphram, etc. That will give you a mental picture for when you are pushing the pedal.

You will find this to be a great clutch setup, unless they come from China now. That may royally screw the deal. The pedal effort is low, yet the holding power is great. A much better rig than the OEM setup, for most all applications.

The 1.5-2 inches of movement at the top is the freeplay needed to keep the TOB from spinning w/ the engine and burning up.

If you have a manual brake setup, the pedal will sit dead even. If power brakes, they sit offset, with the brake pedal a bit lower when all is right.

 

[3836bbl]

Thanks!
Already got a Schumacher torque strap,as well as new z-bar bushings,clip-retainer,and new nylon washers for the linkage.
I can adjust the nut so that my clutch pedal comes all the way up to the stop,however I thought that there was supposed to be 3/4-1 in of free play in there?

 

[SomeCarGuy]

There is suppose to be freeplay. The pedal will still bang back to the stop though.

Do you feel the freeplay when you push the pedal? That is do you feel it push REAL easy for a bit of travel and THEN firm up?

 

[3836bbl]

Been driving the car around town here n there.It just took some getting used to a diaphram style clutch after I've been using a Hayes street/strip with a 3 finger style for 10+ years.
Clutch feels great now!
Thanks for all the replies.
john