Had a problem at the track last night, need advice

[coolblue65]

This was my first trip to the track since last October, so I wanted to get a few runs in before I head back with my new drag radials. Unfortunately it didn't go as well as planned.

Basically during my 1-2, and more so my 2-3 & 3-4 shifts, the clutch pedal seems to occasionally stick in the down position- basically blowing the shift and causing me to over rev it because the clutch is not re-engaging when I take my foot off the pedal.

Anyone ever experience something like this? I have a couple thoughts of what might be causing this and how I can fix but I would like to hear some of all your ideas first.

 

[10secgoal]

Check your pivot point on the clutch pedal. When they blow out, sometimes they hang up about half way.

 

[coolblue65]

Check your pivot point on the clutch pedal. When they blow out, sometimes they hang up about half way.

Do you mean the pivot under the dash?

 

[Cobra ssc]

Make sure that you take out your floor mat also, it can also hang up there.

 

[10secgoal]

Do you mean the pivot under the dash?

Yep

 

[coolblue65]

I will take a look at it tomorrow, is there anything I should be specifically looking for or will it be obvious? I haven't messed around under there for a long time.

 

[iskwezm]

do you have a pedal return spring?

 

[coolblue65]

do you have a pedal return spring?

Yeah I have all stock mechanical clutch linkage.

 

[rhyno9]

Yeah I have all stock mechanical clutch linkage.

That might be your problem. My z bar would flex a bit and would hang up on the headers sometimes. This is exaggerated when the engine rocks back an forth on full throttle blasts.

RV

 

[rbohm]

sounds like the pivot points, all of them, have issues. as was stated start by checking the pedal support bushings as they wear out very badly and cause the pedal to stick against the steering column. you can fix that with a roller bearing conversion kit.

the Z bar bushings at the block and the chassis mount are next as these will allow the Z bar to shift back and forth.

one more thing, if you have a diaphram clutch, that will also cause a problem since the diaphram spring cant overcome centrifugal force at high rpm when released. it is a problem with GM cars. there are fixes for it though which include adding weights to the clutch fingers to force the clutch to move as needed.

 

[iskwezm]

Yeah I have all stock mechanical clutch linkage.

I meant the spring under the dash to the pedal. I dont have one but i never had that problem.

My neighbor has one on his 66 that pulls the pedal up.

 

[rbohm]

I meant the spring under the dash to the pedal. I dont have one but i never had that problem.

My neighbor has one on his 66 that pulls the pedal up.

unless he did what shelby did, that spring is for helping to disengage the clutch, not engage it.

 

[coolblue65]

I meant the spring under the dash to the pedal. I dont have one but i never had that problem.

My neighbor has one on his 66 that pulls the pedal up.

Yeah thats all stock too, I have never touched it. I didn't get a chance to get under their yesterday, I am about to go in the garage to check it out.

 

[coolblue65]

I did not find anything that looked terribly worn out under the dash. I tried to give the pedal a good a shake at different points to see if it felt loose, but it seemed solid under the dash.

The other 2 bushings for the equalizer bar were put in new last summer, I would think they are still in good shape.

I do have a diaghram clutch, but I would think between the spring under the car for the linkage and the sping under the dash that would be enough to pull the pedal back.

I can see how the floor mat can hang up the clutch, because I noticed when I pushed it down gently it would catch for a moment, so I will definately pull the mat out next time.

I am also going to check my motor and trans mounts to make sure they haven't come loose at all.

 

[dennis112]

Sticking to the floor is possible with a diaphragm clutch. Centerforce even recommends that the under dash spring be removed. I first used a centerforce and found that the pedal did indeed stick with high RPM shifts. I then removed the spring and all was well. Since then I have also run a Spec Stage 2+ and now a Long style Ram Sintered Iron setup with the spring removed.

 

[coolblue65]

Sticking to the floor is possible with a diaphragm clutch. Centerforce even recommends that the under dash spring be removed. I first used a centerforce and found that the pedal did indeed stick with high RPM shifts. I then removed the spring and all was well. Since then I have also run a Spec Stage 2+ and now a Long style Ram Sintered Iron setup with the spring removed.

ok until this thread I was under the impression that the spring under the dash, helped return the clutch.

So next question is how in the hell do I remove that big f'n spring easily?

 

[dennis112]

ok until this thread I was under the impression that the spring under the dash, helped return the clutch.

So next question is how in the hell do I remove that big f'n spring easily?

No, return is a function of the pressure plane and it is assisted by the spring on the clutch fork in the engine compartment. The big spring under the dash helps you to push the pedal easier and will not be needed as long as you have a proper engine compartment spring. The under dash spring is kind of a throw back to when clutch design was not as advanced as it is now and stiff clutches were common. A diaphragm clutch does not need the spring. Don't worry, the pedal effort will hardly change at all without it, and it won't stick to the carpet on its own anymore. I can still easily push the pedal with the palm of my hand--especially with the centerforce.

As far as removal, I used a big flat blade screwdriver and simply pried it off. Pay attention to whether the spring is most collapsed when the pedal is on the floor (most probable) or the pedal is released (doubt it.) Collapsed means less spring pressure and so it will be easier to remove--It will not fly out at you like a coil spring so that is not a problem, but don't let it pinch you.

I might have done it by removing the gauge panel, just not sure after a few years. Note that there is a couple of white nylon C shaped bushings found under the spring ends to prevent squeeks or wear damage. They will not be needed anymore.

 

[runawayabc123]

My stang has clutch sticking problems with the headers a previous owner installed. So, check your headers and clutch linkage for signs of rubbing to determine if this is the problem.

 

[coolblue65]

thanks Dennis, I will pull it off one day this week after work, and will let everyone know how it turns out.