Clutch Rod and Pedal Problems

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fenderman33

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I have a 4 speed in my 73 small block Duster. The problem I'm having is with the clutch pedal and the clutch rod. When I first put it all together and adjusted the clutch the pedal would only come back up about half way and I'd have to pull the all the way back up with my foot. Now, after about 100 miles on it the clutch pedal was staying down on the floor and I'd have to pull it up just to get it moving. I pulled the rod that is threaded and goes into the clutch fork out and it's bent a little bit to one side. I don't remember if it was like that when I installed it or not, but could this be causing my pedal problems? If not...what else could it be? I have a factory over center spring on the pedals.
Thanks for any help,
Jon
 
You need to keep adjusting the rod until the pedal returns all the way, but you still some free play between the throwout bearing and pressure plate.
 
I adjusted it as far as I could without the throwout bearing binding up and it still doesn't come all the way up.
Anything else?
Jon
 
You say you have to PULL the pedal up with your foot?
Did you forget the plastic bushings on the ballstuds?
The adjuster rod is SUPPOSED to be bent on the eye end.

Mark.
 
Did you reinstall the clutch return spring? If you look closely, you will see a notch in the upper edge of your clutch fork about 3/4" toward the tranny from the hole your clutch rod goes into. On my /6 there is a spring that runs from this notch to a hole in the bottom of the bracket that holds the clutch pivot ball that the Z bar rides on. If this spring is missing, your clutch linkage will not return to its full upright position. Hope this helps. ;-)
 
I didn't mean to say bind up...rather be touching the pressure plate and not spinning freely. Sorry.
I have all 4 of the plastic pieces on the ballstuds and the return spring on the clutch fork. What am I missing?
-Jon
 
Re-reading your original post, it becomes obvious that it's binding up somehow.
Another stupud question (These are only because at one time I did them!), is your pedal pushrod in backwards?
Remove the pushrod, does the pedal move freely?

I swear, it's usually in the linkages somewhere.

Mark.
 
Another thing I should ask is was this a conversion from auto to 4 speed?
If so, what were the donor pieces, specifically the ball studs and Z-bar/torque shaft, from?

Is it possible that you have slant 6 pieces?
At least some, anyway?

Mark.
 
If I remember right the pedal is free without the rod on it...which way is it supposed to be oriented so I can check if it's backwards or not. I think there was only way I could get it on, but I could be wrong. I'd be willing to double check.
It was converted from a 225/904 to a 318/A833. The zbar and the pedals and the pushrod (that's the one from the pedal to the zbar right?) were from a v8 a body barracuda. The threaded rod and the clutch return spring were from Ed Miller...he said it could've been from an E body.
Thanks for the help...let me know if you have anything else.
-Jon
 
Adjust your clutch so you have about 1-1.5 inch of free play. If you`ve run out of adjustment rod you may need to get a longer one. Brewers Performance sells a very long adjustment rod for use with the big blocks. Is the Ed Miller you`re referring to from Chesapeake, Va.?
 
Yea...that's uncle ed out in hickory. He helped come up with alot of the stuff on my Duster.
If I adjust the rod any farther the throwout bearing will be touching the pressure plate and not spinning free.

-Jon

Longgone said:
Adjust your clutch so you have about 1-1.5 inch of free play. If you`ve run out of adjustment rod you may need to get a longer one. Brewers Performance sells a very long adjustment rod for use with the big blocks. Is the Ed Miller you`re referring to from Chesapeake, Va.?
 
I`ve dealt with Ed on a few occasions and he`s an engaging fellow. He`s helped me out with parts and he`s an old pro with the Mopars. I `d have to agree with FB340, you may have an issue with the (over the pedal) spring. Your fork return spring could be weak, or worst case you may have a bad throwout bearing. I`ve had good results with Brewers Performance, it may be worth a call to them just for a chat, HTH.
 
The overcenter spring and pin are new from Brewer's and installed according to the diagram I found on moparts.net. The clutch and throwout bearing are also new. I'm going to have to check on the rod from the pedal to zbar and then the spring on the fork.
Which way is the rod supposed to be in there so I know if I've got it right or wrong?
Thanks alot...
Jon
 
This should be the same in your Duster. You may have to enlarge it to get a good view of the clutch rod, but this may help you out some.

scan (Small).jpg
 
While I agree that the overcenter spring and fork return spring may play a role in the normal function being problematic, having to PULL the pedal back to get the clutch to engage is far from normal.
I feel that you should remove the pedal pushrod and the adjuster rod, then check the Z-bar for binding BY HAND.

Also, keep in mind that when the tranny loads the clutch with a stock rubber engine mount, the engine and tranny tend to want to twist towards the passenger's side.
Many times I have had a weak, or broken, driver's side mount lock up the clutch linkage, causing the clutch to slip.
You should look closer at the Z-bar pieces to be sure they aren't 6 cylinder ones.

The big tip off to 6 cylinder pieces is the bellhousing ballstud's spacer length.
Where the ball stud is attached to the bracket, to the point it starts to taper, is @ 1/4" on V-8s. The 6 cylinder's is right around 3/4", possibly more.

I know for a fact that if you try to use the 6 cylinder ballstud bracket and a 6 cylinder Z bar, on a smallblock V-8, the 6 cylinder stud spacing rides inside the Z-bar, sometimes with minimal issues, but most times it binds like crazy.

Mark.
 
Here's a couple pics illustrating the ballstud spacing differences, 6 cylinder is the left one, V-8 is the right one.
Note the area the arrows indicate.
The 6 cylinder Z-br is ALSO longer by a similar length.

Mark.

6 studbrkt.jpg


V8 studbrkt.jpg
 
FWIW, The ball pivot on the bellhousing is body specific, it does not make a difference which engine it is (so for an A-body the ball pivot on the bellhousing is the same for \6, sb, bb). The z-bar is body and engine specific. The ball pivot on the frame is also only body specific.

I have a similar situation with my sb 68 Barracuda. If I adjust the free play to spec when the pedal is pushed to the floor the fingers on the pressure plate contact the disk. So I adjusted the freeplay so with the pedal on the floor it does not contact but the pedal only returns to the over center point and will need a little help to return the rest of the way. I thought I had the wrong clutch fork (to short so for a given pedal through it will move the throw out more). I talked with Brewers and determined that I have the correct fork but they did tell me that they had seen the issue I have with some brands of clutch sets. Only fix according to them is to replace the clutch set (I have a new Zoom Clutch set). My current fix is a small block of wood under the carpet that keeps the pedal from going all the way to the floor and the accompanying grinding. This has allowed me to adjust the freeplay so the pedal free play is correct and the pedal returns all the way.

Also, When I first put the A833OD behind the \6 that was orignally in the car I had the problem of the pedal staying on the floor. I had a bellhousing out of a \6 pick-up to accomodate the bigger bearing retainer of the A833OD. Because this bellhousing had a ball pivot for the clutch fork I could not use the one I had and put it together with the truck fork which was much longer. To get the through out bearing to move far enough (longer fork requires more pedal stroke for a given amount of through out motion) I had to adjust all most all the freeplay out. This resulted in the pedal going to far past the over center spring and the pedal would stay on the floor. I fixed that by getting a universal spring that was much stronger than the stock one connected to the clutch fork and installed that. Problem fixed.
 
If it goes in enough to disengage and comes out far enough (foot or otherwise) to achieve a little free play (i.e., completely "en"gage, with the TO bearing free), then is it probably just spring issues and the related matters of mismatched conversion pieces.

For example, mine has a homemade Z-bar and only comes out about 3/4, or sits about two inches lower than the brake. It works fine this way, as long as the above conditions are met. Check all the pivot points and links and proper function, ensure the springs are there and working good, should be all set.

You may find (as I did, upon re-assembly) that things are not lining up quite right, and need to do a little re-fabricating to get it working good.

:thumrigh:
 
dgc333 said:
FWIW, The ball pivot on the bellhousing is body specific...
I partially agree, but Big Block A body is it's own critter.
A body also shares with F, J and M body on the bellhousing bracket.

dgc333 said:
...It does not make a difference which engine it is (so for an A-body the ball pivot on the bellhousing is the same for \6, sb, bb)

Actually, that's not right.
If you look at the pics above, the difference between 6 cylinder and smallblock is dead obvious.
A Big Block A body pivot bracket is way wrong and won't even bolt up to a Smallblock OR slant 6 bellhousing. In fact, the A body Big Block bell is a nearly exact copy of the '65-'66 B body 10-1/2" cast iron one, which utilizes teo 1/2" diamter bolts to mount the bracket down, rather than the 3/8" bolts of the smallblock and six cylinders.
The Big Block A body pivot bracket is also a 2-piece affair, consisting of a bracket backed by a 3/8" piece of steel, with two 1/2" holes drilled into it, to space it away from the starter.

A six cylinder and smallblock Z-bar are nearly identical, the arms are clocked the same, the main tube is the same exact diameter and the arms are positioned in the same places in relation to the clutch pedal and the fork.
The only difference is that the main tube is @ 1/2" to 3/4" longer on the 6 cylinder, which is as simple as shortening it to fit a smallblock.

The big block A body Z-bar is very similar to a smallblock one, except that the arm on the bellhousing side is bent in an 'S' shape to help clear the driver's manifold.

As far as the situation at hand, given that the linkage is correctly adjusted, (even if you you have 6 cylinder parts in place) so long as it's not binding up in some way, even with NO overcenter spring or fork return spring, the pedal should return to normal position.
All the spring on the fork does is keep the linkages tight so that they don't rattle loose, or, in the case of the overcenter spring, help ease downward pedal effort.
The pressure plate does all the rest.


Mark.
 
Actually your pictures do not look like the orignal \6 bracket that was in my 68 Barracuda and the small block bracket does not look like the new sb one Brewers supplied as part of the the z-bar overhaul kit. My comments were based on what Brewers told me.

Also, the sb bellhousing I am using is an OD bellhousing from an F-body. Even though it looks the same as the non-OD bell housings in the area where the ball pivot mounts the casting is enough different that the Z-bar sits at an angle to the back and up when an A-body bracket is used. You need the F-body bracket for everything to line up properly. Brewers has these but I had already modified mine to position the ball stud forward and down to keep the z-bar lined up.
 
Didn't you say that your's still doesn't actually work right, dgc333?
It helps when you have all the correct pieces.

The slant 6 pivot bracket pictured above is still in a '69 Valiant that's never been apart, the V-8 one is still attached to a bellhousing from a '72 340 Duster, which I removed. All lined up correctly.

I do know that the pre-'70 V-8 (and 6 cylinder) pivot brackets don't have the extra arm with the hole at the end, but other than that, they bolt up and function the same.
The positioning is not affected, either.

GUYS, all the comments here pertain to '67-up A bodies, '66 and prior is a whole new can of worms.

Mark.
 
The problem I have is not with the pivot or z-bar. I though it was the wrong fork but I provided the dimensions to Brewers and they confirmed that it was the proper sb fork. They also stated they have run into issues with some brands of clutches where the fingers contact the disk when they are pushed to the floor.

FWIW, Took a look at the Brewers web page and stand corrected the Big block bracket is indeed different. Also, 72 and up sb brackets are different than 71 down units (Brewers has decent pictures of each) . The ball stud for the 72+ in relation to the mounting pad on the bell housing is lower and further forward than the 71 down.
 
Dont Know if this will help but i had clutch problems and found the bearings in the mount for all 3 pedals worn. I mean the ones were the pedals hinge on.
hope this helps.
 
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