Clutch/Transmission Issues, Help Me Diagnose

1991 Power Ram V6 4x4

Hearing a little knock that repeats at the same pattern when in neutral. When clutch is engaged, no sound but I do hear some whining. Also, clutch is having trouble engaging in first gear, seems like it chatters a bit before it catches. Also, clutch pedal went to the floor and I had to lift it up manually. Notice clutch fluid was empty, filled it up, problem no longer there.

Here's what I think:
Clutch pedal to floor
Conclusion: Leak is happening at the master cylinder or slave cylinder. Going to replace both.
Chatter before fully engaged in 1st gear, clutch not fully engaging, replace clutch.
Whining noise when clutch is engaged, throw out bearing.
Chatter when in neutral, I don't know. I really hope it's not a chipped gear.

A chipped gear shouldn't chatter at all. The hydraulics on the clutch are probably way overdue for a rebuild/replacement - do a visual inspection of the hoses as well. If you hear a sort of 'ringing' sound every time you hit the clutch, it's probably the throw out bearing (they can also sound like an old rollerskate) The clutch might be contaminated or have an uneven surface wear patch on the friction material somewhere (might indicate its been cooked or oil has somehow got into the clutch assembly) It's a sucky job but I think you'll need to pull the clutch out and go over everything - flywheel, clutch disc and pressure plate.

Throw out bearing might be your cause for all that noise that you hear. They can be very elusive. That’s a good thing because it’s much easier to replace. Would be a good time to also install a new clutch and surface the flywheel.

Check and make sure your slave to master cylinder flex hose line isn’t leaking and causing you to bleed off. It’s located under the drivers wheel well. I’ve actually been thinking about making a run of braided stainless steel hyd clutch lines for our platform. Ideally they would be more robust, not expand like rubber, and last forever.