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View Full Version : clutch z-bar and linkage angle



warren57
07-21-2012, 01:00 PM
Installed my z-bar and the upper linkage fit perfectly, the bellousing bracket and pivot stud fit just right. But the angle from the z-bar to the clutch fork is pretty steep. It has to be pretty close to stock, as everything lined up with no issues. It looks like there is a lot of downward push while compressing the clutch fork. Seems it would be better with an offset linkage rod or modification to the z-bar to allow for a lower angle of attack. I realize as the z-bar arm goes back, it also goes lower as it reaches it's lowest point 90 degrees below the shaft, but that is still an inch or more higher than the clutch fork centerline. My concern is the clutch fork with the pin design has horizontal movement ability but is fairly solid vertically. The newer style ball connection rod allows movement in all directions, but the 57 pin through rod shaft limits that movement. If it is similar to stock, I guess it's worked for over 50 years and who am I to say it needs a fix... What are you thoughts? Note the second pic shows a straight in line approach. (about 1 1/2" lower)
Thanks

See attached pics.595594593592

chevynut
07-21-2012, 02:37 PM
To me, it looks like the ball is too high on the engine side, especially in the picture taken from the rear (#3).

Rick_L
07-21-2012, 07:05 PM
Warren, as you know I posted a couple of times on your similar thread on the other site.

Chevynut's point that the pivot ball is too high is worthy of noting. I had not commented about that previosly because I didn't see anything out of the ordinary in your photos. One problem you'd have if you lowered the z-bar is that it would require elongating the hole in the firewall for the upper clutch linkage rod. As I recall that was discussed.

Again I think you should at least take this to the point where you find out whether you have a functional problem vs. something that "might" be one.

warren57
07-21-2012, 09:57 PM
It's the camera angle, both balls are within 1/8" if you are looking at them without a tilt. Couldn't get the camera in to get a good pic. The z-bar lines up well, pivots well. I think it's fine. I'll know soon, doing a little work to the header on tht side and going to go see chevynut next week and pick up a stock driveshaft. Getting a little closer every day....

warren57
08-04-2012, 10:26 PM
Well, with the previous rod angle the clutch pushed in, but not smoothly. Felt like things were binding, jerky like rough spots.
So here's where I ended up. Pushes in smoothly, appears to be what I needed and very quick modification. Measured stroke and have slightly more than the previous hook-up but plenty of adjustment both directions.



610611

oldgoat16
10-01-2013, 03:48 PM
Warren, where did you get the bracket bolted to the bellhousing? I'm also in the process of fitting my 55 with the clutch linkage

warren57
10-01-2013, 07:04 PM
Warren, where did you get the bracket bolted to the bellhousing? I'm also in the process of fitting my 55 with the clutch linkage

Well, I had multiple issues, so I did a complete change and all seems to be good.I'll try to keep this short... As Rick suggested I checked the top clutch rod and it was for a 55 not a 57, changed that.
First, the clutch arm on a stock bellhousing exits at 9:00 so alignment isn't an issue. On later bellhousings the clutch arm exits about an inch lower and gets worse out at the end of the clutch arm. It ends up about an 1.5" lower than stock. So, when you push on the clutch you are at a downward angle which applies an upward force on the throwout bearing so some leverage is lost over stock as well as additional friction on the bearing to shaft, which isn't to big a deal, just requires more pedal pressure. I had two throw out bearings fail (actually broke the flange the fork fits into) with this mis-alignment.
So, to fix, I actually did away with the bellhousing bracket and bolted a flat plate directly to the engine mounting holes. Then aligned the zbar horizontally and vertically and drilled/tapped and mounted the ball to the plate. This insured nearly perfect alignment on the zbar. Now, the angle was still there, so to get a more level approach on the arm, I offset the clutch rod to match the clutch arm. At the same time I removed the RAM clutch and pressure plate as it required a lot of force to push in. Went to NAPA and bought a stock 69 Camaro set up. Everything pushes in with little effort and seems to be working good. Attached is a picture, I think you can see the plate bolted to the engine that mounts the zbar to the block and the offset rod.

oldgoat16
10-01-2013, 08:46 PM
Thanks warren this will help, the pictures are great and will help as I try the install on my 55, the bracket that you made seems to be the way to go for me as well, keep you posted, thanks mIke

warren57
10-02-2013, 05:57 PM
Thanks warren this will help, the pictures are great and will help as I try the install on my 55, the bracket that you made seems to be the way to go for me as well, keep you posted, thanks mIke

I had someone ask how I aligned the hole to tap in the plate and get it right. I took the ball out of the frame bracket. Then screwed a piece of all thread rod through the frame bracket hole (from the outside) screwed it in until it touched the plate on the engine. Marked the plate (that's why you see primer in the picture!), drilled and tapped it. removed the all thread, everything fit "like a glove".
Also on the plate bolted to the engine, you have to grind a bevel on the backside top and right edges where they meet the block, as the block is angled slightly at those locations.
Good luck

oldgoat16
10-07-2013, 06:40 PM
thanks warren, great information, its a slow process but worth it , mike