GT350 clutch linkage alignment

[shelbydoug]

  Seems to me the clutch throw out arm is too long.  The arm of the cross shaft almost aligns with the block edge on my GT 350.  Your clutch throwout arm end seem too far left. (wrong side of the exhaust pipe)

That's right or as we tell the kids, "your other left". 

Exactly how the geometry of that set up as shown is going to work is beyond me.

There are no Ford logos or part numbers stamped on those parts. IF the judges choose to climb in there and then decide to deduct points from you for having the wrong part, but it works...I'd take the hit.

The other possibility is that is the wrong H pipe and fork for the car. The z-bar is made to the entire setup. Once you start mixing and matching, you are screwed.

[bhoulis]

Yes. The 390 clutch fork does not seem to work with the hipo bars that people are showing. The question is, are these correct assembly line style z-bars, or a later Boss302 style that superseded the original style. TSB, service replacement. If so then people would have had to change the clutch fork to the shorter style if they were replacing their original z-bars. If these are the correct style bar then the whole argument of "390 clutch forks on hipo motors", as shown in the parts books and supported by some of the more experienced in the Shelby community is a mistake. Waiting to see that one photo of the mythical assembly line z-bar or a good up close undercarriage shot showing the longer 390 fork installed. I'm going to put my ride together with a short fork and the B302 style bar that I paid a chunk for. I'll keep the 390 fork, that I paid another chunk for, until there is some sort of resolution one way or the other. Brian

[shelbydoug]

The shorter the fork, the more effort is needed. I think that you have the thinking correct. The fork that you have does not match the z-bar that you want to use.

Since no one is rushing to post photos, I assume that they aren't sure what they have in use now?

My z-bar is custom made and not stock so there isn't much point in showing what I have but I do know that I have the long fork and the short lever arm on the z-bar in like you say, about 3" from the bell, on the other side of the pipe.

I think that your problem may be a lack of availability of the short fork?

[texas swede]

Here is a picture of the different Z-bars including the 67 K-code and GT350
Texas Swede

[bhoulis]

Thanks Texas. Based on this, the 390 forks for hipos message is false. Brian

[JD]

Texas Swede Thanks for this image!

(reposted rotated, hope you don't mind)

[Bossbill]

This unicorn search started with this thread:
http://www.saacforum.com/index.php?topic=2107.0

In it the various clutch forks were shown with the final determination possibly made by the MPC that the "K/390" fork was concours correct.
Based on that information both Brian and I purchased the longer "K/390" forks. These suckers were fairly tough to find with an impressive price tag. Buy hey, it's a Shelby.

After Brian's mock-up I tried my long fork as well. We are 3" out of bed.

I dug out my Z bar and thought "Oh crap, Brian has the same Z bar as I do. Do I have an issue too?"

So here is the Z bar on my car. It looks exactly like the pic of the 67 Z bar on top left that texas swede posted. And Brian's. I tried to orient it the same way as in the above pic.

If we all agree on this Z bar then we have to go back to fork thread and figure out which fork we REALLY need.

[Bob Gaines]

This unicorn search started with this thread:
http://www.saacforum.com/index.php?topic=2107.0

In it the various clutch forks were shown with the final determination possibly made by the MPC that the "K/390" fork was concours correct.
Based on that information both Brian and I purchased the longer "K/390" forks. These suckers were fairly tough to find with an impressive price tag. Buy hey, it's a Shelby.

After Brian's mock-up I tried my long fork as well. We are 3" out of bed.

I dug out my Z bar and thought "Oh crap, Brian has the same Z bar as I do. Do I have an issue too?"

So here is the Z bar on my car. It looks exactly like the pic of the 67 Z bar on top left that texas swede posted. And Brian's. I tried to orient it the same way as in the above pic.

If we all agree on this Z bar then we have to go back to fork thread and figure out which fork we REALLY need.

Still digesting all of the facts being discussed however the top arm in your picture appears to have a different bend when compared to the picture in reply 18/20. You asked.

[Bossbill]

Bob -- I think that's cell camera parallax where the lens distorts the angle of things.
Are you looking at the angle between the top curved bar and the hollow tube?
All of the angles between the tube and the top and bottom bars are 90 deg, regardless of what the photo purports to show.

If you want other pics, let me know and I'll use a real camera.

[Bob Gaines]

Bob -- I think that's cell camera parallax where the lens distorts the angle of things.
Are you looking at the angle between the top curved bar and the hollow tube?
All of the angles between the tube and the top and bottom bars are 90 deg, regardless of what the photo purports to show.

If you want other pics, let me know and I'll use a real camera.

Yes that angle looks taller in your picture compared to the other but that might be a illusion.

[shelbydoug]

It's the location of the short arm on all of them that determines the length of the fork. IF the correct location of the short arm needs to be as close as possible to the bell, then a shorter fork HAS to be used.

You can't possibly mix the longer fork to those z-s. The geometry would be terrible.

IF all you can use is the longer fork, then you HAVE to relocate the short arm 3 inches out, to the other side of that exhaust.

With the shorter fork, the 2600# clutch makes sense then. You likely will need power assist to the clutch pedal to use and aftermarket clutch with the shorter fork AND you positively will tear up and twist everything in site.

[67350#1242]

With the shorter fork, the 2600# clutch makes sense then. You likely will need power assist to the clutch pedal to use and aftermarket clutch with the shorter fork AND you positively will tear up and twist everything in site.

That is why most every driver car you see will have a reinforced Z-bar.  I'll bet even the light clutch caused the top arm of the bar to twist over time. 

[shelbydoug]

Do you know how many people don't even realize that the z is twisted? I would say...most!

That is what I expect to happen with it. Some have been successful with having the original "hardened" but by doing so it also becomes brittle and can crack through the high stress spot just above the weld.

I just double the top arched piece and quench the weld in water. That will harden the steel about as much as you can do anyway.

Great pic. Thanks for posting that. Seeing is believing.

[Bossbill]

Ok, I'd like wrap up the Z-bar portion of the 67 GT350 clutch linkage.

• According to Post #8 from 67350#1242  we have an actual part number on a Z bar that matches the MPC.


• Attached is a scan of the 68 MPC I snagged from the concoursmustang.com site courtesy of 67gta289 that indicates the -H Z bar is correct (as a replacement part)


• That part very closely (without holding in our hands) matches texas swedes's picture from the HiPo book.


• That part very closely matches Brian's Z bar in post #1.


• That part very closely matches the Z bar that has come from my car and has been in my possession for the last 35 years and has not been changed during that time.


• http://www.concoursmustang.com/forum/index.php?topic=18682.msg118274#msg118274 shows a Z bar with a paper tag showing C7ZZ-7528-A on a Z bar that matches the -H bar we've shown so far. It's thought this was just the letter 'H' written so that the letter's top tips joined forming an inadvertent A

Perhaps it's time to move on and figure out what the clutch fork of a 67 HiPo looks like that matches this arm. See http://www.saacforum.com/index.php?topic=2107.0

[bhoulis]

Update. Received my new Ford tooling clutch fork today, the one listed for regular 67 289s, and release rod. Mocked up and looks like there shouldn't be any alignment troubles. The pic with rod installed has the z-bar about 1/4" shy of being all the way on the pivot because the rod was hitting the wooden engine cart. But the felt washer should just about make up for the space so should be a good representation of how things will be once installed. Middle pic has 2 pieces of threaded rod nutted together to make a shorter rod to check alignment with zbar pushed all the way onto the block pivot. This was before I realized the felt washer would take up the space. Hope this helps get us towards a more final conclusion. There may be other factory original parts out there for this combination but these are readily available to keep things moving. Hope this helps. Brian