67 Z bars and clutch rods, OEM and repop - Chevelle Tech
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post #1 of 20 (permalink) Old Sep 16th, 11, 4:29 AM Thread Starter
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Gary
 
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67 Z bars and clutch rods, OEM and repop

In '67 there were two versions of both BB & SB Z bars. There was a mid-year change on both. The 66 and very early 67 Z bars had a straight upper arm, while the later ones (2nd Design GM 3921040) had a curved upper arm. This meant there could have been a mid year change for the upper push rods which I can not confirm. This was true for the small blocks & the big blocks. See the attached Photos of the photos of the late 67 Z Bars


The 67 Z Bar 2nd Design (GM 3921040) has the upper curved arm thats has the same bend (dog leg) as a 68 Z Bar / bellcrank. It makes the clutch linkage geometry align perfectly. (the only difference between the early 67 and the late 67 is the upper arm which has a Bend (dog leg) which aligns better with the pedal rod and eliminates side loading on the bellcrank.



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Last edited by Tom Mobley; Sep 17th, 11 at 12:47 AM.
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post #2 of 20 (permalink) Old Sep 16th, 11, 4:36 AM Thread Starter
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Re: 67 Z Bars 396

The 66- Early 67 Z Bar Design had a straight upper arm. See Photo. Also see Photo of 67 Z Bar second Design with offset upper arm installed.
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post #3 of 20 (permalink) Old Sep 16th, 11, 4:48 AM Thread Starter
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Re: 67 Z Bars 396

The 1966 Clutch Pedal Rod had a bend near the center of the rod. See Photo of 66 Clutch Rod with 66 Clutch Pedals. The 1967 Clutch Pedal Rod had a bend in the rod farther down and closer to the firewall. See Photo of 67 Clutch Rod with 67 Clutch Pedals.
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post #4 of 20 (permalink) Old Sep 16th, 11, 5:04 AM Thread Starter
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Re: 67 Z Bars 396

The After Market Clutch Rods are not properly machined and have wide 90 degree bends which interfere with the clutch pedal operation. The Original Clutch Rods have a machined shoulder that is very close to the 90 degree end of the rod where the rod attaches to the pedal and the upper Z Bar rod. See Photo of 66 Original Clutch Rod with tight 90 ends and compare with photo After Market Clutch Rods which causes interference at interior attachment point because the After Market Rod has wide 90 ends not machined close to the 90 degree bend in Clutch Rod and causes the bend in the rod to rub against the 67 Clutch Pedal Housing.
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post #5 of 20 (permalink) Old Sep 16th, 11, 5:18 AM Thread Starter
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Re: 67 Z Bars 396

A Photo of the 67 Clutch Pedals shows the wide bend in the After Market Clutch Rod that hits and interferes with the Frame of the Clutch Pedal Assembly which causes interference and binding. Also a Photo of an Original Clutch Rod End that is properly machined with the tight 90 degree end which gives more clearance away from the Clutch Pedal Frame and allows a smoother operation to disengage the clutch.
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post #6 of 20 (permalink) Old Sep 16th, 11, 5:45 AM Thread Starter
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Re: 67 Z Bars 396

I had made a earlier mistake in this Post about the 1966 clutch rod having a bend in the middle of the clutch rod and the 1967 clutch rod having a bend farther down and closer to the firewall. I have both rods in front of me and the bends are both the same, but there is a difference in the length of the 1966 when compared to the 1967 clutch rod. The 1966 clutch rod is 13" long center to center where it attaches to the Z bar and the clutch pedal. The 1967 clutch rod is 13 3/8" long center to center where it attaches to the Z bar and the clutch pedal which is due to the new 1967 Chevelle Shock absorbing steering column and the one year design in the frame that holds the clutch and brake pedals and steering column.

Because the aftermarket Clutch Rods are improperly machined and an original rod can not be found, there are Companies that makes a Heim Clutch rod Setup for the 67-81 Camaro (7010-125) with a Bend in the middle of the Rod which I believe will work better than the straight Chevelle rod setup. A sample of the 67-81 Camaro Rod is found at this internet address:
http://cmc.speeddirect.com/itemdesc....010%2DFBIRD&Tp=

The Heim Rod setup for the Chevelle is straight and has no bend in the center of the rod. A sample of the 66-67 Rod Setup is found at this internet address: http://speeddirect.com/index.aspx?nodeID=1

The Hiem ends do offer the necessary clearance (tight bend) which allows smooth clutch operation.
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Last edited by Gary 396; Sep 16th, 11 at 5:39 PM.
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post #7 of 20 (permalink) Old Sep 16th, 11, 7:04 AM Thread Starter
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Re: 67 Z Bars 396

Here are 2 Internet Articles for the Heim Clutch Rod Installation for 66 - 67 Chevelles. This first one is found at:
http://www.superchevy.com/technical/...its/index.html

And a second Article is found at: http://www.chevyhiperformance.com/te...ild/index.html

Also a Photo of a Heim Clutch Rod Installation on a 1966 Chevelle that shows the clearance between Heim end and Clutch Pedal Frame. Note that the Clutch Rod is not in a fully closed position in relation to upper Clutch Pedal Rubber stop where the 90 degree Clutch Rod clearance will be tighter when the clutch pedal rests on the Rubber Clutch Pedal Stop.
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Last edited by Gary 396; Sep 16th, 11 at 8:13 AM.
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post #8 of 20 (permalink) Old Sep 16th, 11, 8:48 AM
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Jon
 
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Re: 67 Z Bars 396

I guess I now know why my aftermarket clutch rod doesn't fit right. I had to modify the steering column bracket for the rod to work. Tkanks for the info.
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post #9 of 20 (permalink) Old Sep 16th, 11, 12:31 PM
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Re: 67 Z Bars 396

Gary appreciate the information.
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post #10 of 20 (permalink) Old Sep 16th, 11, 5:45 PM Thread Starter
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Re: 67 Z Bars 396

Dear Jerry, Thanks for the encouragement. Gary 396
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post #11 of 20 (permalink) Old Sep 16th, 11, 8:23 PM
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Re: 67 Z Bars 396

Thanks for taking time to post and take the pics. Mind if I edit the title a little?

Stuck.

Tom Terrific or Terrible Tom, depending on the phase of the moon, passing cosmic rays or other factors not fully understood except by my wife.
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post #12 of 20 (permalink) Old Sep 16th, 11, 11:12 PM Thread Starter
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Re: 67 Z Bars 396

Tom the more the merrier. Go for it. Gary 396
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post #13 of 20 (permalink) Old May 5th, 12, 12:29 PM Thread Starter
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Re: 67 Z bars and clutch rods, OEM and repop

Here is a Photo of an original 1966 to early 1967 Chevelle Z Bar being GM Part Number 3872895. If you look closely, you will notice the slight bend in the Z Bar arm about 1" inch before the (hole) at the tip of this Z Bar arm where the clutch rod connects to the bell housing fork. This slight bend in both the early and late design allows for better rod alignment. The aftermarket Chevelle Z Bars do not have this slight bend. If you look at the first post photo of the later design Zbar you can see the cease in the metal for this slight bend. Another way to improve alignment / clearance of the Chevelle Z Bar arm especially when you have headers on a 396 is to use a cresent wrench while the Zbar is hookedup (except disconnect the bellhousing rod from the clutch rod with the oil filter removed). Then tighten the cresent wrench down on the very end of the Zbar and move the Zbar arm to the position that bests clears your headers and the engine block. Do not over bend the clutch arm as you may break the welds on the arm. Also, Chevelles with headers that hit or rub the Lower Control Arms can be adjusted for more clearance by buying some heavy duty tie down straps and wrapping them around both headers (and positioned on the top and below the transmission) tightening them together which bend the headers inward and give you the required header clearance. If possible, leave these straps on over night. The Headers should move enough to give you an extra 1/4 to 1/2" inch clearance.
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Last edited by Gary 396; May 5th, 12 at 1:04 PM.
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post #14 of 20 (permalink) Old Mar 12th, 13, 9:16 PM
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Re: 67 Z bars and clutch rods, OEM and repop

Gary now I know who out bidded me on that Z-bar.
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post #15 of 20 (permalink) Old Mar 17th, 13, 5:32 PM
Daniel
 
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Re: 67 Z bars and clutch rods, OEM and repop

I have an auto Skylark that I am converting to a 6 speed manual. I'm about to pick up a set of Chevelle manual pedals. Is the mounting bracket for the brake pedal in an auto car the same as the mounting bracket for a manual car? The pedals don't seem to come with any bracketry. I'm planning on using these repops:

http://www.ecklerschevelle.com/cheve...1968-1972.html
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