Erratic Clutch pedal

[dvw]

With the spring in the location shown, no over center spring, correct adjustment and good Z bar bushings everything should set against the upper pedal stop and not rattle. If the pedal is low and not touching the stop raise it with the adjustment. Then add a pedal stop so the disengagement at the disc (aprox.060") is correct. Mine does not rattle, has well over 100 passes at the track, 10 years use on the street. Never rattles, shudders, or slips.
Doug

 

[moparedtn]

 

[moparedtn]

With the spring in the location shown, no over center spring, correct adjustment and good Z bar bushings everything should set against the upper pedal stop and not rattle. If the pedal is low and not touching the stop raise it with the adjustment. Then add a pedal stop so the disengagement at the disc (aprox.060") is correct. Mine does not rattle, has well over 100 passes at the track, 10 years use on the street. Never rattles, shudders, or slips.
Doug

I'm glad yours works where it is, Doug. That must mean it engages/disengages pretty quickly, towards the top of pedal travel?
I can't at this point even see that there's enough adjustment left on mine to get the pedal that high, but then, that's where an adjustable pedal stop might come in handy?

Yes, it is possible to adjust the pedal height (using the adjuster nut on the fork rod) to wherever you like as long as you have threads left on the fork rod.
Again, I did confirm with not only Brewer's but Centerforce tech support themselves that the "normal" position for the pedal when running no pedal return spring is for the pedal to "droop", especially if you set it like I like mine (about halfway up).
That means there's plenty of "up travel" left in the pedal for it to bounce around as vibrations make it slide up and down the elongated hole on the end of the clutch pedal rod.

In other words, there's nothing "wrong" with the way mine is (given the type of clutch and the fact the over-center spring is detached).
It's just a matter of what I'm willing to do to make it acceptable for me.
I like where in the pedal travel the clutch is engaging/disengaging right now. That leaves me with what to do with the slop above that.

 

[moparedtn]

It's still only held by a spring.. it can move if need be. If everything is adjusted correctly and the spring is pulling everything tight then the pivot shaft is against the firewall end of that clutch rods slot. Shouldn't rattle. The slot is there so when you dump the clutch it allows the pedal to come up without immediately pulling the fork rod back harshly.
It's you that is asking for help here, not us, and a few of us are trying to help you but you don't want to listen apparently. I've been wrenching mopar since I was 14, a mere 42 years ago and growing. Guess I'll move on and help someone else.

So your solution would be - to keep adjusting on the fork rod until the z-bar pivot is against the other end of clutch rod slot, therefore taking up the slop,
correct?

I'm old too, Dad. Been working on rides a long time too.
I appreciate all the effort, of course.
Please take a moment to not only refer to the pics I've posted directly from the FSM as well as to actually read what I'm posting.

Even the wisest man knows he doesn't know everything. I discuss and ask questions until I "get it" - or until the answer is squeezed out of whatever it is.
I can do so without losing my temper. Might drive others crazy, but the intent is good on my end.
For example, I re-learned today from Dan Brewer something that hadn't occurred to me in this whole process:
When I expressed to him how far I had already had to run the adjusting nut out on the fork rod and was concerned about future wear adjustments, he reminded me that those were going to involve actually running the nut back in on the rod, not the opposite.
In other words, nothing to be concerned about.
Scratched my head for a moment and realized the man knew what he was talking about.

 

[dadsbee]

Well if you don't want the clutch pedal way up where Ma Chrysler put it originally, against the rubber bump stop, then fabricate a new stop at the location height that you want your pedal. Then all of what DVW, oldmoparman and myself stated will be correct and your pedal rattles will be gone.

So your solution would be - to keep adjusting on the fork rod until the z-bar pivot is against the other end of clutch rod slot, therefore taking up the slop,
correct?

If your fork spring has tension still in it and it's not bottomed out, it should be putting that pivot against the firewall end of the clutch rods slot period, has nothing to do with fork rod adjustment. Fork rod adjustment is to set clearance between throw out bearing and pressure plate fingers.

 

[moparedtn]

Well if you don't want the clutch pedal way up where Ma Chrysler put it originally, against the rubber bump stop, then fabricate a new stop at the location height that you want your pedal. Then all of what DVW, oldmoparman and myself stated will be correct and your pedal rattles will be gone.

Yes, of course I want the pedal to rest at the top like normal.
That's out the window once the over-center spring is disconnected, since that's part of its' "job".
I currently have the clutch set to disengage/engage at about halfway in the pedal travel - and since this type clutch pretty much engages all at once (think of it as an on-off switch and you'll be close), that leaves a lot of slop between that point and up to the top of pedal travel, which currently has nothing in place to pull it up to.

If your fork spring has tension still in it and it's not bottomed out, it should be putting that pivot against the firewall end of the clutch rods slot period, has nothing to do with fork rod adjustment. Fork rod adjustment is to set clearance between throw out bearing and pressure plate fingers.

Ok so yes, then you are saying I need to continue cranking on the fork adjuster nut.
As you know, if the fork spring has enough tension in it on initial installation to be a minor bear to get on (and trust me, it did), then it's only going to have more tension on it as I crank on the adjuster nut - isn't it?

Hold on a sec - let me ask a really stupid question here - to raise the clutch engagement point at the pedal, I do adjust the nut towards the fork more, right?

 

[Dennis H]

I'm reading this because there is a loud screach when depressing the clutch pedal. Rhythmic loud complaint. Release clutch and sound goes away. Mostly. Like a loud shhhh. Throw out bearing I guess. Sudden and dramatic onset. No recent work. Drove the car 300 miles home like that with perfect clutch performance. Clutch has about 60k on it. Plan to have the bearing replaced and leave clutch alone if nothing apparent wrong with it. It works too good to mess with. The howling will scare the crap out of you if a long way from home. On occasion,you need to toe-out the pedal 1/4 inch to full out.

 

[oldmanmopar]

What you need to do is take it back to the shop that fixed the trans noise. He should have taken care of the rattle when he fixed your trans that he put the bearings in after you and your friend properly installed a tail shaft. That noise you had was was probably caused by the rear bearing not snap ringed into the tail shaft housing correctly causing the main shaft to float. Seen and heard it before.

 

[oldmanmopar]

When you use this style pressure plate your engagement will be higher than factory You will also have less free play. I just did one last week The car works perfect no slip no rattles. Grabs high and will torch drag radials. Your fork spring will act as your peddle return for free play if your linkage is not binding. You need to just listen and just try this. Or you could call Jamey at Passion. didn't he send you a trans that didn't shift?? or did it!

 

[Daves69]

If more adjustment thread is the ticket, maybe consider an Abody rod in place of the Bbody.

 

[moparedtn]

I'm reading this because there is a loud screach when depressing the clutch pedal. Rhythmic loud complaint. Release clutch and sound goes away. Mostly. Like a loud shhhh. Throw out bearing I guess. Sudden and dramatic onset. No recent work. Drove the car 300 miles home like that with perfect clutch performance. Clutch has about 60k on it. Plan to have the bearing replaced and leave clutch alone if nothing apparent wrong with it. It works too good to mess with. The howling will scare the crap out of you if a long way from home. On occasion,you need to toe-out the pedal 1/4 inch to full out.

I know that sound all too well.
In fact, the Passon unit I sent back last week for refund did that from the get-go; turns out, something out of whack in the reverse part of the innards was causing it. We saw that the reverse check ball retainer bolt wasn't run all the way in and tight when we got the unit out of the crate, but hey, it's under warranty and Passon is the expert, so we installed it.
Bad idea. That thing screamed like we were torturing cats anytime I let the clutch out, especially in 3rd.
The local transmission guy that wound up fixing my old unit had one look at the Passon unit and said "yep, they didn't finish assembly. Problem is in the reverse part down below. Thing is trying to be in two gears (reverse + whatever forward gear selected) at the same time."
Out it came and back to PA....

 

[moparedtn]

When you use this style pressure plate your engagement will be higher than factory You will also have less free play. I just did one last week The car works perfect no slip no rattles. Grabs high and will torch drag radials. Your fork spring will act as your peddle return for free play if your linkage is not binding. You need to just listen and just try this. Or you could call Jamey at Passion. didn't he send you a trans that didn't shift?? or did it!

I'm getting the jist of what you folks who actually have this clutch are saying here: "grabs high" is about the gist of it.
One must have the experience/frame of reference of actually owning/installing one of these type clutches to know what I'm trying to say and OMM, you obviously have that experience.

The funny part is I already understand that, it's just that I want this thing to drive like the old B&B style clutch and it simply can't.
My adjusting it to engage halfway down pedal travel isn't going to work unless I can a)stand the pedal flopping around while in gear or b)cobbling up a light spring under dash to pull the thing the rest of the way up.
Sadly, it drives just fine other than the flippity flopping of the pedal in that position.
The only alternative is to do like you all say and run the adjustment all the way up so it engages high, real high - then the adjustment itself is holding the pedal up there and the rattle would conceivably be much less.

It's interesting to note that the FSM says the proper way to adjust the clutch (remember: Mopar was referring to the factory B&B style clutch in their manuals) is to get a 5/32" "free play" at the end of the fork, which they say will equal 1" at the pedal - so they're saying to adjust the pedal "high" as well.
I'm assuming that measurement equates to the proper air gap between the throwout bearing and the clutch fingers?
THAT is the critical dimension to me in all this - whatever I do, I cannot let the throwout bearing ride on the clutch fingers when the pedal is released under any circumstances - in fact, I wonder now if that wasn't happening before and is the mystery noise nobody could identify in my car?

Oh yeah, I did catch your dig about Passon. Ouch.
That's not cool. Lesson learned...

 

[Daves69]

So, as I understand, you're comfortable where the release is but you desire full peddle travel.
More out of the box????
How about a torsion spring around the peddle shaft?

 

[moparedtn]

So, as I understand, you're comfortable where the release is but you desire full peddle travel.
More out of the box????
How about a torsion spring around the peddle shaft?
View attachment 602190

Thought had crossed my mind, yessir.
Then I thought "do I really want to try to disassemble the pedal?"
Ummmm....no, no I don't.

 

[440+6]

I just read through all this and I've been running centerforce clutches in three different vehicles for the last 20 something years, my GTX being one of them, the pedal grabs about 3 in off the floor the pedal comes all the way up to the bump stop the only spring that's pulling it is the one from the bellhousing to the clutch Fork, and they work flawlessly.
Remember there are thousands upon thousands of people out there with these clutches and don't have any problems whatsoever.

 

[moparedtn]

Good grief.
Look, nobody here is saying it's a bad product. Centerforce, to their credit, confirms everything I'm experiencing with mine, in fact.
Says it's "normal" - and sorry, the DualFriction is a different critter from any other of their (or anyone elses') clutches.
One cannot apply the usual and normal standards to it that we do with "normal" clutches and the factory setup wasn't designed for it,
so there's going to be some adjusting to do.
No problems "whatsoever"? Nonsense. Can't prove an absolute. All one has to do is a quick Google to find all sorts of folks fussing about the
things, after all.
Doesn't matter, I'm not throwing in the towel on mine because I do like the feel of the thing.

In fact, this evening I decided to reinstall the clip up top where the pedal rod hits the z-bar, the one the "mechanic" screwed up and lost.
Found it was easier to install it through the wheelwell through the rectangular access cover.
That snugged things up a little.
Then I happened to look over at the z-bar pivot on the frame and sure enough, Mr. Goodwrench had forgotten to tighten that nut as well.
If the z-bar wasn't such a tight fit between bellhousing and that pivot, I'm sure it would have fallen off the damn ball pivot, in fact.
Sheesh.
Thus followed an hour session under the car, re-checking everything all over again.

I know I couldn't do the job (pulling and replacing the transmission) this time on my own anymore, but he turns out not to have been the answer.
I've never had anyone else work on anything of mine, but I have to now - the cancer has taken too much out of me.
It just won't be him next time, unless I just work something out to rent his lift in the future.

Net result of tonight is a lot less wiggle in the motion. Pedal position didn't change; I did nothing to cause it to.
That will come tomorrow, if I'm able.

 

[440+6]

BTW mine are all dual friction centerforce. your comment on googling people that have problems if pretty funny, I'm sure you can Google any product and find a variety of people that are having problems with even the simplest of things.
The point is that it's a clutch and set up properly it will work properly. Usually there is something else causing it to not operate correctly, just got to find it.

 

[moparedtn]

BTW mine are all dual friction centerforce. your comment on googling people that have problems if pretty funny, I'm sure you can Google any product and find a variety of people that are having problems with even the simplest of things.
The point is that it's a clutch and set up properly it will work properly. Usually there is something else causing it to not operate correctly, just got to find it.

That was the point, yeah. No product works great for everyone in every situation and no manufacturer gets it right every time.
You can't prove an absolute...
Even amongst a random sampling of the same cars, there was soooo much variation in manufacturing new and certainly over 50 years there's been more
that even the factory service manuals' instructions have to be considered guidance, not absolute.
In my example, I'll toss in a couple just on this car:
The car was converted to 4 speed by a previous owner - one of the results being the z-bar pivot anchor on the frame isn't quite where it should be and makes things tight when installing the z-bar. It works where it is, just makes it hard to get it in there using the usual methods.
(I'm not knocking him; he did also save the car from a field behind a barn and did all the metal replacement of all floors, pans and rear quarters!)
Another possible variation on mine is that I suspect the z-bar in it is actually one from another application that has been modified to work in the car.
Again, he got it close, but as I documented in another thread when I was building the mechanicals back up on the car, things aren't exactly right on it.

God willing, I'll get under the thing today and play with the adjustment nut again. If the FSM says "adjust the fork so that there is 5/32" free play", that's where I'll start, because that's supposed to equal 1" at the pedal.
If it winds up I need to run the longer a-body rod, I'll go there, too.
I have too much money in this clutch to simply toss it at this point and again, I DO like how it feels.

 

[coloradodave]

That was the point, yeah. No product works great for everyone in every situation and no manufacturer gets it right every time.
You can't prove an absolute...
Even amongst a random sampling of the same cars, there was soooo much variation in manufacturing new and certainly over 50 years there's been more
that even the factory service manuals' instructions have to be considered guidance, not absolute.
In my example, I'll toss in a couple just on this car:
The car was converted to 4 speed by a previous owner - one of the results being the z-bar pivot anchor on the frame isn't quite where it should be and makes things tight when installing the z-bar. It works where it is, just makes it hard to get it in there using the usual methods.
(I'm not knocking him; he did also save the car from a field behind a barn and did all the metal replacement of all floors, pans and rear quarters!)
Another possible variation on mine is that I suspect the z-bar in it is actually one from another application that has been modified to work in the car.
Again, he got it close, but as I documented in another thread when I was building the mechanicals back up on the car, things aren't exactly right on it.

God willing, I'll get under the thing today and play with the adjustment nut again. If the FSM says "adjust the fork so that there is 5/32" free play", that's where I'll start, because that's supposed to equal 1" at the pedal.
If it winds up I need to run the longer a-body rod, I'll go there, too.
I have too much money in this clutch to simply toss it at this point and again, I DO like how it feels.

Ed, forget the 'factory manual' for adjusting your clutch. You have an aftermarket clutch now so you want to follow Centerforce's instructions. As you stated, who knows what parts were used in all your linkage pieces? Here is my suggestion:
1) Pull your inspection cover and put the car on jackstands.
2) Have your wife push the peddle to the floor while you get under the car and check the clearance between the clutch disc and the pressure plate. It should be right at .060". If not, adjust the lower clutch rod to get that clearance with the peddle to the floor.
3) Have your wife let-up the clutch peddle and see where it lands. If it's not high enough for you, you need to lengthen the upper rod, even if it means removing it and welding in an extension, preferably with adjustment ability. Make sure the upper 'bump' stop is in place and the lower spring on the T/O fork is installed. Then check to make sure the T/O bearing is sitting away from the diaphragm cone (fingers) approximately .125" to .250".
Once you have it adjusted correctly and working, you can alter the engagement point higher if you wish through installing an adjustable clutch stop and re-adjusting the rods.
I can't help thinking that a mismatch in parts is causing you undue stress, which, in and of itself, is not healthy...
I don't want to get on you too much, but a thorough inspection of the linkage initially while someone worked the clutch peddle might have saved you some grief my friend.

 

[moparedtn]

Ed, forget the 'factory manual' for adjusting your clutch. You have an aftermarket clutch now so you want to follow Centerforce's instructions. As you stated, who knows what parts were used in all your linkage pieces? Here is my suggestion:
1) Pull your inspection cover and put the car on jackstands.
2) Have your wife push the peddle to the floor while you get under the car and check the clearance between the clutch disc and the pressure plate. It should be right at .060". If not, adjust the lower clutch rod to get that clearance with the peddle to the floor.
3) Have your wife let-up the clutch peddle and see where it lands. If it's not high enough for you, you need to lengthen the upper rod, even if it means removing it and welding in an extension, preferably with adjustment ability. Make sure the upper 'bump' stop is in place and the lower spring on the T/O fork is installed. Then check to make sure the T/O bearing is sitting away from the diaphragm cone (fingers) approximately .125" to .250".
Once you have it adjusted correctly and working, you can alter the engagement point higher if you wish through installing an adjustable clutch stop and re-adjusting the rods.
I can't help thinking that a mismatch in parts is causing you undue stress, which, in and of itself, is not healthy...
I don't want to get on you too much, but a thorough inspection of the linkage initially while someone worked the clutch peddle might have saved you some grief my friend.

Always glad to hear from you, my friend, and I appreciate your concern, I really do.
I spent a good amount of this afternoon under the car, investigating just what you describe and I have to make one statement right now before I go any further to everyone who has tried to help me:
I get it now. I really do get it! I apologize to anyone I offended with my loggerheadedness.
I had an epiphany of sorts while under there - things have to follow a logical progression in order for me to understand them.
Merely telling me how to do something is always, without fail, going to be followed up in my head by the "why does it work like that?" part.
That's where I was stuck and why I wasn't digging what was happening.

Allow me to ramble on some:
Bottom line on this critter is that when you're cranking on the adjuster nut on the fork rod, you aren't moving the throwout bearing or any internal clutch parts - you are moving the linkage, which in turn raises the pedal.
I know now what some of you were trying to tell me on this; I had to see it in action myself.
I got under the car and took a pic of where the adjuster was with the then current adjustment (halfway up pedal travel) and it looked like this:

I then got under the dash and wedged the pedal all the way up, then got back under the car...
AHA! Now I see what's happening!
The rod had pulled out of the fork hole some, giving me an idea of how much more adjusting I could get away with.
That's when the light bulb finally came on over my noggin.... and I understood.

I then spent the next three hours under the car, taking off and re-installing correctly the snap rings on the joints, putting the washer/isolator back on the fork in the proper orientation, tightening all the bolts in the transmission mount and bellhousing, etc.
I then cranked on the adjuster nut some more to this point:

That raised the pedal up some from where it was, but not all the way up. Since I like it to release/engage about 2/3 of the way up, I was good with this.
Further, since all my fixing what Mr. Goodwrench had done had snugged things up in the linkage a bunch, the annoying pedal rattle also disappeared.

I was so pleased with all this that I stopped right there and went to address the shifter/transmission issue - yes, despite my giving the mechanic the actual Hurst instruction sheet and showing him how to install the shifter, he botched the 1-2 rod adjustment anyways, which I've since worked on as well.
Hell, the main shifter body bolt was even loose....sheesh.

Results are the clutch operates where I like it and the pedal rests about 2/3 of the way up.
I'm good with that. No , I didn't wind up installing a makeshift spring under the dash to pull the pedal the rest of the way up.
I might do that one day after my new stop pad arrives from Brewer's , but I doubt it.
Clutch feels good, shifter feels good, car is back to normal running-wise as well.
It was good enough news to offset the phone call from the docs, in fact. Reckon the middle of the month, the next round of tests and nuclear scan this and iodine that begin, all leading to more hacking on me or whatever. I don't care about it all that much, to be honest. Not my first rodeo...

Again, my apologies to anyone offended by my questioning and discussing this to death.
I get it now. I really do.

Oh, a little bonus for the car after I was done today: