Loud Clunk When Engaging Clutch

foney_email said:

It was an assumption. All original 3 speed and 389. Something definitely tightened up while driving and the clutch became harder to push. Then it started the noise when pressed.
It was either heat or the rain, but I’m not sure. Is the clutch pedal connected to the trans with linkage? I’m new to this car and haven’t gotten into it yet.

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Suggest the first thing you do is get a 1965 Service Manual - very helpful with text, photos, diagrams. These "old" cars have nothing in common with "new" cars.

No cable for clutch - that's "newer" car stuff along with hydraulic throw-out bearings.

Hard pedal sounds more like clutch/clutch fork, throw-out bearing issue. Clutch pedal has a rod that connects to the arm/lever on the top of the "bellcrank". The bellcrank is attached to the frame on one side and a pivot ball screwed into the side of the block. On the bottom of the bellcrank is the arm that has the clutch adjusting rod that seats into the small stamped cup of the clutch fork. The clutch fork rides on a pivot ball within the bell housing. The end of the clutch fork is shaped like a "C" and fits over the retaining collar on the throw-out bearing. Pushing in the clutch pedal causes the linkages to move and apply force to the clutch fork which in turn pivots on the bell housing pivot ball (a fulcrum) and pushes in on the throw-out bearing which then applies force/pressure to the diaphragm (pressure plate) "fingers" and releases/lifts the diaphragm off the clutch disc to disengage the disc from the flywheel so the trans can free wheel when making the next shift.

There is typically a return spring that attaches to the bellcrank to return the pedal to its top. There is also a small spring that attaches from the lower bellcrank arm to the clutch fork to keep tension on the clutch adjusting rod so it does not pop out of the clutch fork stamped cup.

There are also bushing found at the pedal attachment under the dash. These can wear out as they are plastic/nylon. The pedal rod going through the firewall attaches to the pedal through a hole in the pedal and a clip holds it in place. Years of use will wear/elongate the hole and/or wear the rod end that goes through the hole down. This can cause binging. Same goes for the other end as well as the lower linkage. The bellcrank also has a bushing, and it and the ball can wear out causing binding.

If an engine mount has broken and the engine shifts or raises up upon acceleration, this can cause binding in the bellcrank or linkages.

If the clutch fork has fallen off the pivot ball in the bell, this can cause a hard pedal and eventual throw-out failure and even worse if parts break. Have not had a diaphrgam(pressure plate) go bad, just wear out and not grab or chattered real bad indicating replacement.

The throw-out bearing could be binding on the transmission collar if something broke or is cocked rather than sliding straight and smooth. Could be "other."

These are just a few things to look at and check. What you don't want is something to break out on the road or the clutch set-up to let go at speed and do severe damage. I would not "assume" anything to be original or replaced - KNOW first hand so you don't have a major malfunction.

Looks like I am missing the cover. Does that seem right? It’s all unfamiliar to me.

If I push in the clutch cold, no squeaking or noise. Lots of oil and trans fluid all over everything. I’m not sure where to start. Is there a sight plug to tell if I have enough manual trans fluid in there? It looks like a lot of trans fluid on the ground, but it’s hard to tell where it’s coming from. First time under here. I wiped down everything so I can start tracing down the leaks.
I’m worried about what leaks I may cause, but I’m going to foam and spray everything down so I can clean all this up.