Conversion from auto to manual on '67 with '68 400. Z bar support bracket welded on top of frame rail from factory, not bolted to side. Big block z bar fit perfectly on bracket and ball stud.
Car has stock appearing power brake booster. Also newer frame repair (no rust anywhere now) with fresh motor mounts done. Z bar upper arm hits bottom of booster by about 1/8 inch ...
I'm guessing motor is a tad bit raised ? I cut 1/4" of upper Z bar arm off in straight mid-arm portion (just above curve) and re-welded end with hole back onto Z bar arm. Now clears. Do you all think that will work and can I adjust out the difference at adjuster rod ? Thanks !
Clearance is good now after shortening upper zbar arm by 1/4". Linkage all hooked up and clutch disengages properly.
2 questions :
- clutch pedal sits1" lower than brake pedal at top of swing, up against rubber stop. If I remove rubber stop, they are even but pedal hits metal brace loudly. How should it be ?
- clutch pedal does not return to up position. Everything moving freely, greased. Linkage uses only 1 "clutch return spring" from hole in fork to frame bracket attached at brake line clamp as seen in many diagrams. Spring is not strong enough. My '67 service manual shows 2 springs. First is "anti-rattle spring" that holds pushrod into fork (hooked up just like my spring now) and second spring is "clutch pedal return spring" running from hole in upper zbar hole to .... somewhere unknown. I've looked for hole on body/frame connector as described in Camaro forums and that configuration is not there on 67 Firebird. Thoughts ? Right now I have heavier spring ordered. Next thought is second spring from lower zbar arm running forward to starter bracket or to hose clamp on my Ram Air exhaust ? Not sure what to do to get proper return on pedal. Service manual has 2 springs but I see nothing in forum describing this. Thanks.
take off all the springs and rods and check that the Z bar itself moves without any binding. Check the rod that goes thru the firewall is not binding up on the hole in the firewall. Or is the pedal itself binding up on the hanger. You really shouldn't need a ton of spring force to bring the pedal back up. Also remember you can change the leverage by where the rods are mounted on the arm on the Z bar. A longer arm gives more leverage but needs more travel. You could modify the stop for the clutch pedal to come up a bit more. Maybe the brake pedal is sitting higher than it should so the clutch pedal looks lower.
I agree with Chief on checking easy stuff first. Welded the bracket? Is it located properly? The Z-bar should be nowhere near the brake booster.
As for the pedal return I grew tired of that too. I finally added a third spring that goes from the clutch pedal to the back of the dash. That pulls the pedal all the way up no problem. So I have one spring pulling the clutch fork forward, one spring between the fork and Z-bar keeping the lower rod tight, and one spring pulling the pedal back to the dash. I use the rubber stop on both pedals and they are even.
Relocating the rod holes in the Z-bar can change the geometry drastically. The last time I rebuilt my manual trans, I reused the pressure plate, flywheel, throwout bearing, clutchfork, everything but the disc. I put a brand new disc in. That caused all sorts of problems. I could not have pedal free play and still get full disengagement. I needed more travel from the lower rod. I am using the Speed Pro spherical rod end upper and lower adjustable rod set. I still could not adjust things properly. I had to drill another hole for the upper rod in the Z-bar about an inch lower than the stock hole. That way I got a lot more lower rod travel. It changed the angle of the upper rod and I had to relocate the firewall hole. Overall I prefer this set up and I don't feel any extra pedal effort.
Thanks everyone. Here's what I did. Pulled the z-bar out and greased the hell out of it (again), and lubricated both clutch pedal rod and gromet opening at firewall. Replaced the clutch return spring that came in the new z-bar kit with one that matched the looks in the Pontiac service manual. Easy to get once I knew what it was. It was clearly heavier. Clutch pedal pops right up now. Rubber clutch bumper stop I purchased from Ames was just over 1" tall. I shaved it down to 1/8" and pedals line up perfectly. Clutch adjustment easy, drives perfect with new 4 speed. Thank you all !
