Z Bar

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Jay B

Jay B

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1969 Swinger, 340 4Spd, Doug's ceramic coated headers. I started with a Slant 6 Z-Bar, I converted to 340 with Dougs Headers, according to drawings i saw on this site. I dont get enough throw to disengage pressure plate and have any free play. At pedal rest throwout bearing is close to diaphram but not enough travel to disengage. LUK clutch. Must be overlooking something obvious...
 
If you modified the z-bar, or not, this is what the mod should be.
We had a fella mod the z-bar, but "clocked it" wrong and kinda had issues like you are experiencing.

IMG_20240512_202833.jpg
 
Last edited:
Edited last picture

The down arm should swing freely between the two upper tubes.
Adjust (bend) as nec. after the above modification.
 
That's the drawing i used, almost positive i got it right. Not too sure about throwout arm and pivot in bellhousing though. I cant figure out how to attach photos from phone.
 
The other common problem is wrong pivot mount on trans.
The z-bar should be sorta square to the engine/trans assembly.
Check a few posts ago. (trans section)
Uncle Bob? Had some decent pics from above of shaft "attitude".
 
Hit the attach photo button.

Are you adjusted all the way out on the lower rod that goes to the throw mount pivot?

IMG_4512.png
 
you get the same if the bar is not in the right position in respect to the rail.

push it right up to the chassis rail. add the spring clip and then move it slowly away until you see the spring clip ends sink into the grooves in the white nylon half moon bushes on that side.

if you don't get this right the bar moves across towards the bellhousing. the spring clip ends sit past the inner end of the half moon bushes and all seems well but your clutch doesn't work due to the fact that the z bar in 3/4 of an inch in towards the centre of the car.
the angles are all slightly off and the spring clip for the pushrod binds on the pushrod eye.

the above scenario seems obvious. but is so easy to get wrong.
have to wonder how many Z bars have had their lower arms bent and twisted to "get them to work" when the issue is incorrect mounting

dave
 
I have a TII Z bar and Dougs. I had to shim the z-bar over to the bell housing and get a clickable starter to get everything to clear. I also had to install a return spring under the dash with a Diaphragm clutch. Sometimes you gotta' do what you have to do to get things to line up.

FYI I had the same fitment issues with a modified to print stock bar too.
 
The first coupla z-bars I altered, I had to re-alter (re-clock) as well, lol
The spring clip is easily overlooked, thnx Dave.
The bar in backwards/reversed can mess it up too.
Good luck, and patience .
 
Inertia said:
The other common problem is wrong pivot mount on trans.
The z-bar should be sorta square to the engine/trans assembly.
Check a few posts ago. (trans section)
Uncle Bob? Had some decent pics from above of shaft "attitude".
Click to expand...
Yeah I did but AFAICT those showed how mine was out of whack and I haven't taken any photos of it since fixing that. I'll see what I can find though.

Basically the Z-bar has to be level and parallel to the frame rail. The two pivots should be directly across from each other.

I bought a TTI z-bar to work with the Doug's headers, it works great, or at least the pedal feels right. It definitely has enough trave to disengage the disc. I set it up using a 1/4" stack of feeler gauges between the TO bearing and the PP fingers (per McLeod's instructions) then tightened it up a little bit after that to get it where it needs to be.
 
Dave999 said:
push it right up to the chassis rail. add the spring clip and then move it slowly away until you see the spring clip ends sink into the grooves in the white nylon half moon bushes on that side.
Click to expand...
I put mine in the opposite way - completely assembled the frame rail side so I knew for certain the spacing was right on that side, shoved the bellhousing side all the way into the z-bar so I had room to start the frame rail side stud, threaded the nut on the outside for the pivot ball, then pulled it back out until the pivot bracket met the bellhousing.
 
Inertia said:
If you modified the z-bar, or not, this is what the mod should be.
We had a fella mod the z-bar, but "clocked it" wrong and kinda had issues like you are experiencing.

View attachment 1716249251
Click to expand...
Thank you for this, no mention of clocking position on drawing, I did it as I could tell from drawing. Do you think I could be that far off where it is far from correct. Pedal at rest throw out bearing close but not touching
 
Jay B said:
Thank you for this, no mention of clocking position on drawing, I did it as I could tell from drawing. Do you think I could be that far off where it is far from correct. Pedal at rest throw out bearing close but not touching
Click to expand...
That is why I just bought the TTI part instead of cutting one apart to rework it. I could see me putting it too close to the edge, or too far away, or clocked wrong.

Even the TTI part is very close. I don't think it would take much of an error to start running into things.
 
Jay B said:
Thank you for this, no mention of clocking position on drawing, I did it as I could tell from drawing. Do you think I could be that far off where it is far from correct. Pedal at rest throw out bearing close but not touching
Click to expand...

It is certainly overlooked. My first took 2 tries, next took one.
If you look at the pic Bob supplied, you can see the down arm is in the "7" o'clock when at rest, if out of clock, some "back" movement is wasted going up/down.
I can't put what I want to say into type. Sheesh.
 
Let me know if I can help. My Z-bar is on the workbench right now. I would think you need the angle between the two arms, but am not sure how I could measure it accurately enough to be more than a guess.
 
Here's something else;
The Slanty clutch pedal ratio is different from a V8-pedal. Maybe that translates in to the freeplay issue as well.
Here's what's important;
after the Z-bar is installed and all the linkages etc. are hooked up, and the freeplay is adjusted; the Fork needs to be all the way towards the rad-side of the window in the BH with just enough room to install the boot.
If it is there and you still cannot get clutch departure, then almost obviously, there is a ratio problem.
If it is not there, but is further towards the back of the car, you'll have some hunting to do, as to the why of it. and most likely is that the fork-pivot is too short.
Other possibilities are; that the Z-bar clocking is wrong; or that the down rod is wrong; or the pedal is not parking correctly, none of which I have ever seen.

As others have said;
The Z-bar, in front view needs to be about parallel to the ground, and in Top view needs to be at 90* to the centerline of the car, and properly anchored on the bushings at the frame end.
There are more than one Bellhouse and matching pivots and different fork stand-offs, and even forks, made, so that mixing parts is not allowed.
Good luck
 
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