clutch won't disengage

74914 · 10-24-2002, 09:56 AM

Hi all,
Sorry for the length. The clutch on my stock ’70-4 doesn’t like to disengage; sometimes. Tunnel tube’s OK. No flex in pedal sheet metal mounting area. When the clutch is depressed all the way, the clutch arm on tranny is moving until it hits a tranny nut, so I think I’m getting all the arm motion I’m going to get. Clutch cable adj nut has many washers under it. I looked with a flashlight into the tranny opening and, while someone presses in the clutch, can see the cylindrical shape of the throwout bearing disappearing into the pressure plate. I also noticed that if I loosen the cable and flop the arm around I can see the shiny ball that it pivots on, but the ball appears to move with the arm if I lift the arm. It likewise appears to re-seat when I move the arm the other way, and kind of clicks in. It almost looks like the ball screw/arm pivot is either stripped in its threaded hole, or the hole threads are gone or the hole area/embossment inside the bellhousing is broken. I checked my ’74 trans and can see some slop in the arm/ball mating even with the retainer U-clip tightly installed, but no ball movement. But I can “clear” the clutch sometimes. I jacked up one side of the car and had the wife depress the clutch while it was in 1st. I grabbed the free r wheel and jerked it back and forth against the engine compression and it “clunked” free. Then I started it and went back and forth in the driveway with no grinding or engagement/disengagement problems. Then it started to grind a bit while finding 1st or rev. I shut it off and started in gear with clutch depressed…started to jerk the car while turning over, then broke free and started, back in “good mode”. Clutch does appear to engage pretty low on the floor.

Background: Car was garaged in '86. I picked it up a month ago. Replaced gas lines, cleaned tank, changed oil, used Marvel, bunch of other stuff and got it running. Seemed to shift OK...occasional grinding if I didn't hit 2nd before 1st or rev, or double clutch (same as my old '74). Chatters if not feathered just right but figure there's probably crud/oil/leaks in the bellhousing. Motor and tranny mounts look OK but haven’t confirmed. Now, after having redone the brakes, I initially couldn't get it to disengage. I found this out after starting in neutral and not being able to engage 1st or rev w/out grinding. Turned it off, put it in 1st with clutch depressed, then started it and almost crashed into garage door...it fired and I got to test the brakes!

Any ideas?? Could crud cause the clutch to stick to the p plate or flywheel? Could the mounting point for the ball screw/pivot actually break and basically recess the ball so I lose travel?

Thanks; I appreciate any feedback

Ed

JWest · 10-24-2002, 10:12 AM

There is a plastic bushing in the arm on that ball to add to the equation. I think you need to pull the tranny (not hard) to get at the arm, pivot, and clutch to solve the problem. The last thing you want to do is injure the tranny by fighting against a non-operating clutch. These trannys don't take to shifting abuse too well.

John2kx · John2kx's Garage

I'm agree with James. Looks like you need to pull trans. to at least fix problem with pivot ball. A good time to fix the "chatter" problem too while your in there.

John

Brad Roberts · 10-24-2002, 03:17 PM

Disc is stuck to the flywheel.

Rock the car back and forth (HARD) in fifth gear (while somebody has their foot on the clutch pedal)

Then go back and rock it in second gear.

You'll still need to get inside the clutch area soon.

B

URY914 · URY914's Garage

I had the same stuck to the flywheel problem before also. Do as Brad says. It can be a PITA but it will break it frre.

74914 · 10-25-2002, 06:25 AM

Yeah...guess I knew that was coming. Time to drop tran. I'm hoping that I can drop it by itself, and thought I read about it somewhere but don't remember where.
Thank you all for the feedback!
Ed

karlp · 10-25-2002, 08:26 AM

Tran. is easy enough to drop. You might want to take the opportunity to drop the engine and transmission as a unit, clean it all up and stuff.
Before I found how easy it was to get parts, I took the ball out of a rearview mirror to replace the one in the arm for the TO bearing. Still working fine a year later.
The ball stud on the transmission housing will leak gear lube into the clutch area if it is not tight. I used a little permatex under mine, and a washer to get the correct height.
The correct height is important. I believe my Hanes manual lists it.