Clutch issues

Discussion in 'U-shift em' started by SCamaroSS2000, Apr 24, 2016.

  1. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    I was driving my 70 gs 350. All of a sudden I heard a pop and my clutch pedal went to the floor. I was able to pull it into anew empty school. The car feels like it is engaged into gear. I can move the shifter but the wheels are locked. I will get it towed into a tranny shop. Any ideas? I assume something with the linjage? It is a mechanical clutch.
     
  2. buick64203

    buick64203 Just plum crazy Staff Member

    You may have snapped the ball stud on the block. Did that once in my 442. Z bar fell off the block and the pedal went to the floor. Did you try and restart it? Did the car lurch forward?
     
  3. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    Car couldn'the restart. Pedal feel is toast. Ideas?
     
  4. buick64203

    buick64203 Just plum crazy Staff Member

    You should of been able to crank the engine with the pedal to the floor. The engine has no idea whats going on with the transmission. All the engine knows is that the clutch pedal is to the floor and the safety switch is engaged. What your saying doesn't really make sense
     
  5. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    I just tried again. First two time nothing happened. Third time though car cranked and did exactly what you said. It tried to lunge forward.
     
  6. buick64203

    buick64203 Just plum crazy Staff Member

    The Z bar is essentially a bell crank. It pivots on two studs- one that's screwed into the block and the other is attached to a bracket on the frame. It connects the upper clutch rod to the clutch fork. If one of the pivots breaks, the Z bar linkage falls down and the adjusting rod usually falls out of the cup in the clutch fork. Like I said in the earlier post, its possible that the ball stud snapped or you lost a cotter pin and the lower rod from the Z bar to the fork fell off. Had that happen too- Lower adjusting rod fell off driving down the road. Heard a clinking noise as the linkage fell to the ground at speed and the pedal went to the floor. Had to walk back down the road and pick up the pieces! :spank:

    Its common for the ball stud on the block to snap off. Take a look at the z bar and see whats going on. If you like, I have my 4 speed car in my driveway, I can take a picture of what Im talking about.
     
  7. buick64203

    buick64203 Just plum crazy Staff Member

    The Z bar is essentially a bell crank. It pivots on two studs- one that's screwed into the block and the other is attached to a bracket on the frame. It connects the upper clutch rod to the clutch fork. If one of the pivots breaks, the Z bar linkage falls down and the adjusting rod usually falls out of the cup in the clutch fork. Like I said in the earlier post, its possible that the ball stud snapped or you lost a cotter pin and the lower rod from the Z bar to the fork fell off. Had that happen too- Lower adjusting rod fell off driving down the road. Heard a clinking noise as the linkage fell to the ground at speed and the pedal went to the floor. Had to walk back down the road and pick up the pieces! :spank:

    Take a look at the z bar and see whats going on. If you like, I have my 4 speed car in my driveway, I can take a picture of what Im talking about.
     
  8. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    I'd appreciate a picture.
     
  9. buick64203

    buick64203 Just plum crazy Staff Member

    Here are a couple of pictures for you. In the first pic, you can see the upper clutch rod coming out from the pedal to the Z bar( the part Im pointing to). You can also see the frame side bracket that it swivels on. In the second picture, you can see the adjusting rod that goes from the Z bar to the fork. There is also a spring that goes from the fork to the frame. The spring keeps tension on the linkage so the pedal springs back up inside the car. In your case, it also keeps the lower adjusting rod in the cup of the fork. You fork has a cup on the linkage end. My big block has a clevis pin on the linkage end so the spring on your car serves double duty. Clear as mud? :Dou::grin:

    20160424_190615[1].jpg 20160424_190638[1].jpg
     
  10. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    The second picture is it. I see a rod drooping down. The side with the cotter pin is entact. I can't see where the other side attaches too though. Should I be driving back to look for parts.
     
  11. buick64203

    buick64203 Just plum crazy Staff Member

    So the lower rod dropped out. That's the best case senario. Sounds like the spring snapped off or broke. The spring goes from the fork to the frame. In the forst pic, you can see the little cup on he end of the fork. The small hole is where the one end of the spring attaches. There is a small hole in the frame right where the engine cradle attaches. In the second pic, you can see the exploded diagram of the linkage. You might be able to make out where the other end of the spring attaches to the frame.

    as far as a new frame, Dorman makes a clutch return spring assortment. The one in my car is one out of that assortment that I used. I cant tell you which one, its been a while. I remember having to take a needle nose pliers and make "U" ends. I think I make have cut it to the proper length as well. I see a trip to an auto parts store in your immediate future! Good luck, we're all counting on you.

    EDIT- my pics are screwed up. The middle pic is the assembly manual showing the spring and where it attaches

    View attachment 333281
     

    Attached Files:

  12. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    I found the cup and tried to put the rod into the cup. It went in but there is no tension. Also the fork with the cup is easy to push in. Am I missing something?
     
  13. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    The spring is intact. The rod is back in the cup but there is no tension. Is there something potentially wrong with the fork that the cup attaches to?
     
  14. buick64203

    buick64203 Just plum crazy Staff Member

    Then I would look closely at the Z bar to make sure its two pivot points are intact. Is the z bar still attached to where its supposed to be?
     
  15. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    It appears to be intact and connected. I can move it through what seems like it is its natural motion. Maybe something with lash adjustment?
     
  16. buick64203

    buick64203 Just plum crazy Staff Member

    Check all connection points starting with the pedal. Look up in the dash and make sure the upper rod is connected to the pedal. The bracket on the pedal may have snapped
     
  17. SCamaroSS2000

    SCamaroSS2000 Well-Known Member

    I think you were right initially. It is the z bar connection to the frame. The bolt is busted and isn't connected to the u joint on the frame. Sorry that I missed that earlier. It was a little shady. I should have grabbed a flashlight to see things better
     
  18. buick64203

    buick64203 Just plum crazy Staff Member

    The good news is its better than dealing with a snapped bolt in the block! Glad you got it figured out
     

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