Have a question on my 57 Chevy. The z-bar is level between the frame and the engine and square. The frame bracket is in the original position. The bellhousing bracket that mounts the pivot ball for the z-bar on the engine side is a manufactured item that is at a fixed height. The clutch arm is much lower in elevation than the z-bar. The linkage arm that is attached on the bottom of the z-bar takes up some of the elevation change, thus leaving the linkage rod at a downward angle from the z-bar to the clutch arm. The clutch arm is a fixed spot and the z-bar is a fixed spot. Any idea what's wrong? Z-bar is the correct one for a 57. Pushing down on an angle to the clutch arm rather than a more level approach can't be right Anyone out there have a trifive chevy with a stick that could send me a picture of the linkage rod angle from the z-bar to the clutch arm? Any other suggestions are welcome. I could extend the linkage arm on the z-bar, but that would likely change the stroke and pedal force required to engage the clutch. Thanks
I suggest you look into this. I have a home made version on my roadster which is installed on an early sbc bell housing and works great. It has a very direct linkage without flexing or binding. I hope this helps. http://www.novak-adapt.com/catalog/clutch/kit_hcrc.htm
It's been awhile since I had a '57 stick shift but the factory bell housing was steel and had the motor mounts bolted to it and the frame. With that bellhousing the angle would be correct. The later Aluminum housings have the throw out arm hole lower and that would explain your angle. You might try another housing or better still, convert to a hydraulic slave cylinder.
Easiest fix is to extend the "Z" bar. If anything it will shorten the pedal stroke and make for better leverage.
I have two stick shift 57 cars, one a hot rodded wagon and the other is stock. I know on my wagon, the linkage is exactly like yours. I will have to check my stock Belair and see how that one looks.
You may want to check the angle with the clutch engaged when the lower bell crank arm is vertical. It may look a little less severe. If there is no binding on the clutch arm you may be alright. Lengthening the bottom arm will change the angle but will increase pedal pressure and shorten the felt clutch release point.
RE: my post #5. I checked my cars and the retrofit into my wagon has 1/2" more slope than my stock setup. Yours looks a little more steep though. Does it work? You can always put a slight bend in the push rod closer to the fork end. Where in Colorado are you?
Lengthening the arm will shorten the stroke, but it wont make for better leverage. The longer the upper arm is, the better the leverage. But lengthening the lower arm creates more pedal pressure, and worse leverage.
Obviously NOT the stock setup; as already mentioned, a cast iron bell housing with mounts that bolted to "ears" on the frame was stock, side mounts and a rear trans cross member mount are now in use, and therefore everything has had to be "custom" designed to work. Even if everything is aftermarket, there are slight variations in these cars frames; the front suspension cross member can even become distorted over time. Plus, many aftermarket side mounts are designed to move the engine forward, anywhere from 1/2 an inch to 2 inches forward; that affects clutch linkage angles. Many tri-five cars are using hydraulic clutch mechanisms now; use a late Camaro bellhousing and either a firewall mounted master cylinder for it, or one of the underdash "hidden" being marketed (you can buy a kit or make it yourself). If you get an assembly manual (reprint of the factory one), it has all the measurements. Butch/56sedandelivery.
Thanks for everyone's thoughts. Here's where I'm at today... the rod pushes down and pops the clutch arm off the pivot ball in the bellhousing and destroys the throwout bearing. Have ruined two so far... Have it all removed from the engine today. After research, it seems the stock bellhousings had the clutch arm exiting at the 9:00 position, directly on center of the transmission shaft (see pics of stock), The later model aluminum bellhousings have the clutch arm exiting at a lower level. Thee arm is not at the centerline of the trans shaft. This lowers the arm about an inch (again see pics). I've been trying to find info on any gm bellhousing that has the higher shaft exit but no luck so far. I may end up extending the lower z-bar tab an inch and living with the pedal hardness.(which I don't like) On another site, a member cut the rod in half and welded a piece of 1"X1/4" flat bar between the two pieces, thus leveling this out. He said it works fine and feels no change in force required and adjustment remains unchanged. May have to give that a try...
Here's a couple of pics that show the inch or so problem with the bellhousing z-bar ball mount attached... Note there is about a 3" difference and the lower z-bar linkage take up about 2", so I have about a 1" issue...
I'm not far from you. In Lochbuie, just off I-76 and Baseline Rd (WCR2) Attached is a picture of what another guy did and he says it worked great, no problems. If you ever have your stock setup off the ground and can take a picture of it, I would appreciate it. Thanks Warren
What about putting the stock front and rear motor mounts back in? The stock mounts are a good, stable and troublefree design. Then either a stock bellhousing or a Lakewood scattershield could be used, thus fixing the clutch linkage problems.
Here's a picture of what I did using stock 1956 Chevy parts, a cheap scattershield, some steel and measurements from a HAMBer.
Torkwrench- If I had any of the parts, I probably would. The car was an original stick, but the previous owner installed a 454/turbo 400, so all the mounts were changed. I pulled out the 454 to use as a boat anchor and installed a GM Performance 350 HO and back to a stick, with a Muncie 4 speed. All the underdash clutch assembly was never removed, so all I had to do (so I thought) was add the z-bar and linkage rods. Think I will start checking out scatter shields. Thanks
I've come to the conclusion that there must be thousands of trifives out there with late model bellhousings and are working fine, so I am checking rod lengths etc. now to see if something is wrong...
have an update.... removed the Ram clutch kit and installed a new OEM 69 Camaro set. Replaced the upper clutch linkage from pedal to a-bar with the correct 57 rod. Aligned z-bar with clutch rods. Bent a 1" offset in the lower rod to level the push approach to the clutch arm. WOW! what a difference, you can push the pedal in with your hand/arm. Everything operates smooth. Now I just need to test drive to verify stroke is good.... Thanks for everyone's thoughts.
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