Clutch Adjustment??

[Rockett]

My '69 Roadrunner clutch doesn't *engage* until fairly high up in the pedal movement range. At least it seems high to me. Does this indicate clutch wear? (This car has had less than 1,000 miles since 2002, which is when it went through an extensive restoration & then taken to car shows after that on a trailer.)

The 1969 Plymouth Service Manual says, "...no adjustment for wear being provided in the clutch itself. The clutch pedal linkage, however, is provided with an adjustable rod to maintain specified pedal free play."

That looks like a pretty straight forward procedure, but I'm not sure if "pedal free play" and what I'm describing above is the same complaint?

Any advice for this Newbie?

 

[moparwacko]

What type of clutch was installed?
Also does it release completely?
The FSM will have somewhat detailed instructions.
Old school feel is about 1/2 - 3/4 inch of free pedal travel if I remember correctly.
At least mine does, and works well.

 

[Rockett]

What type of clutch was installed?
Also does it release completely?
The FSM will have somewhat detailed instructions.
Old school feel is about 1/2 - 3/4 inch of free pedal travel if I remember correctly.
At least mine does, and works well.

The clutch seems to fully engage & disengage. Just seems like this happens too high up in the pedal travel. I have no idea what clutch might have been installed. The car is very "stock" overall. Pedal is as I remember them to be "back in the day" ...not a stiff performance pedal. FSM says that 5/32" free play at the fork will result in "the prescribed 1" free play at the pedal."
I was kind of wondering if the clutch engagement at high pedal travel is a "wear" problem &/or if the "pedal free play" adjustment is really what I need.

 

[AR67GTX]

Yes, as a clutch disc wears thinner the plate fingers extend further to the rear, positioning the TO bearing further to the rear, which throws the outer end of the fork and the lower bellcrank lever forward, the upper lever rearward, and using up free play at top of pedal (point of engagement moves higher up on pedal stroke). Not unusual for a bit of this to happen on a new clutch disc as the fuzzies and soft surface organics wear in and the clutch settles in - but I wouldn't think you would notice a large amount of movement. Probably the linkage just needs to be adjusted down at the lower rod to the fork. Shortening the rod length will increase the top of pedal free play and move the points of engagement/disengagement lower.

 

[Jerry Hall]

The clutch adjusting rod is the only adjustment that I am aware of. I adjust my clutches to start engaging about 2" off the floor and let the so called free play be what it is. I have never really measured for specific free play.

 

[Rockett]

Ok, so it sounds like I'll need to adjust that rod for a larger gap to the fork ...at least 5/16" per FSM (= 1" free play at the pedal), but perhaps more if I want clutch engagement closer to the floor (2" off the floor would be great!). I'm guessing there's maybe close to 7" of possible pedal travel? if so, then mine is engaging at about 4" off the floor. Or, put another way, I'm more than halfway up with the pedal before I get any action.

So how does one know when a new clutch disc is needed? Just keep adjusting it as it wears, until the thing starts slipping at full engagement? Or, eventually one cannot back the rod away from the folk anymore?

 

[Dennis H]

Less than a thousand miles since 2002. Jesus Chrysler.

For years, I had a great clutch. 2” from the floor as above and a good linear feel. The throwout bearing went after 70k plus miles. New clutch. Now let it out and it doesn’t engage doesn’t engage, then engages unexpectedly. And it seems to chafe. Much lighter feel, but not happy.

I put about a thousand miles on it, hoping it will settle in. Mostly freeway though.

 

[steve340]

Were the clutch engages off the floor can be affected by a few factors.
A flywheel heavily machined down or a worn clutch plate are two of the things that can be.
The most important thing so you do not burn the clutch out is "freeplay". Make sure you have the correct amount or you are heading for problems.
Adjust the freeplay correctly and if the clutch engages/disengages and does not slip I would not worry to much about were it takes up. My 2 cents.

 

[PurpleBeeper]

Wow....all of these are good points, though not all of them agree. I've tried the factory service manual flywheel/disc distance method, the 1" of "free play" method & the "adjust the pedal where you want" method. I have no doubt that following factory adjustment methods will give you maxiumum clutch life...no doubt.

BUT, I've found that you can adjust the pedal pretty far up or down without a problem. All the way down (clutch won't fully engage, can't get into 1st or reverse, etc) or All the way up (I think the throwout bearing backs up into the transmission case????) and you may see some issues.

Short version....adjust it where you like the pedal, but do it "within reason" using the lock nut on the adjustment rod under the car.

 

[Daves69]

I have no idea what clutch might have been installed.

Is the over-center spring still on the pedal assembly? I believe it is fairly common to remove it when installing a diaphragm clutch in place of a B&B. So that may be an indication. You likely need the spring on a B&B. It works in both directions when adjusted properly. It assists your leg in releasing the clutch to overcome clutch spring pressure. It also serves to return the pedal to the top when past the over-center position.
For the B&B you don't want so much pedal that you drive the finger backsides into the disc hub springs when the pedal is pushed to the floor. With the pedal up the bearing must be clear of the fingers.

 

[Dennis H]

Forgot, the last inch of return has to be toed up.

 

[AR67GTX]

Forgot, the last inch of return has to be toed up.

Yeah - what causes that? A friend with a 69 Hemi Roadrunner that I helped him reassemble exhibits that. Can't recall the type of pressure plate he used off hand - think it is a diaphragm type but would have to check. Pedal returns smoothly but hangs up about an 1 - 1-1/2 inches from top and with a nudge of the toe then pops the rest of the way up.

His clutch pedal rests way high also - far above the brake but he does have power brakes. The clutch pedal has a thin rubber bumper on the stop (maybe 1/8" thick). And his rod at the transmission is adjusted very short which puts it running at a bit of an angle between the fork and Z-bar. We've basically adjusted the clutch where top of pedal free play ends around the height of the hanging pedal. Does this sound screwed up? It would drive me crazy to drive a clutch like this.

Sorry for the highjack.

 

[5.7 hemi]

Seems like a good distance from the Tb to the clutch fingers. My hydraulic set up calls for no more than .125.

 

[Dipstick]

Ok, so it sounds like I'll need to adjust that rod for a larger gap to the fork ...at least 5/16" per FSM (= 1" free play at the pedal),

Uh, make that 5/32".

 

[Rockett]

Uh, make that 5/32".

YES, you are correct, sir! Thanks!

 

[Rockett]

Ok, I got the car up on ramps today & went underneath & adjusted the clutch. So easy to do, & the pedal is *perfect* now! I don't have to bring the pedal *way up* before I get clutch engagement. (I realized that I had *zero* freeplay at the pedal ...& very little to none between the adjusting nut & the clutch folk!)

I'm a newbie, having recently bought this car off the Internet, after only seeing photos. So nice that I'm easily sorting out a few issues.

I was expecting to find *two* nuts on the rod, so as to "lock" against each other. But, just as the FSM shows, there is a single, "...self-locking adjusting nut". Problem is, it's not very "self-locking". It doesn't spin freely, but for the most part I can turn it easily with a wrench (or my fingers, if I try). Hardware store was closed, so I made the adjustment with that nut.

What are the chances that the nut will turn on its own during normal driving?

 

[Jcharger]

I have a locking nut in addition to the nut. It can turn on itself, but once set with both nuts stays put. The original adjustment was set to be up high (almost tractor high) and the return spring avoids the toe up. My son who learned on a late model car really does not like the clutch engagement where it is, and I think it also makes it a little slower to shift. For mine, I put a spacer to take some travel out and lowered the position where it engages. They can back all the way out and if without retaining clips can fall out - had that happen to me many years ago.

 

[steve340]

I put a locking nut on my one. It was easy to get the adjustment rod off.
It is nice to know the adjustment will not move from where you set it.

 

[Daves69]

That "flex type" nut should close up on the adjustment rod flat with help from the tapered ID of the washer it seats in to prevent it from backing off. Then too, if you need a lock nut,...….. use a lock nut!

 

[Rockett]

View attachment 785057 View attachment 785076

That "flex type" nut should close up on the adjustment rod flat with help from the tapered ID of the washer it seats in to prevent it from backing off. Then too, if you need a lock nut,...….. use a lock nut!

Yes, that's exactly what I've got (ref your photos). But there's supposed to be a 5/32" gap there from the nut to the washer (=1" pedal free play), & that's what brought my clutch engagement down from the top of pedal travel (previously, I had zero gap at the nut to washer & zero pedal free play with all the clutch action towards the top of pedal travel).

Anyway, now that I've got it adjusted per FSM & it feels right, I was thinking of getting a true "locking type" nut with the ring of plastic material inside, ...or else just adding another nut to "jam lock" the adjusting nut.

Shouldn't that OEM "self locking adjusting nut" have a little ring of plastic inside the "castle area" ("flex area") of the nut? Otherwise, it's only finger tight, at best, it seems. Perhaps when it presses on the washer it kind of "locks down", but when cruising along without using the clutch, there's a 5/32" gap there (FSM). Seems like it could rotate on the threads & change position.