Strange intermittent clutch action with '86

[jdbunda]

At first, I thought I was imagining this, but it's happened dozen or so times now over the past couple weeks. At first I thought it was my imagination, but I have since convinced myself it is real.

What would cause this: Every now and then, the clutch pedal seem to become heavier, with uneven pedal pressure required over its travel (i.e. heavier spring action at the bottom of the travel than at the top). The clutch works normally in terms of engagement, just the effort and spring action seem strange. The funny thing is, two or three times later, it reverts back to normal. The first time it did this, I thought I felt something mechanical "let go" and I half suspected something had broken, but it shortly reverted to normal behavior, and didn't do it again for several days.

My car is an '86, so no hydraulics, correct? It's not grainy or crunchy as I've read described in some other recent clutch threads. I have seen the description of opening up the pedal box and cleaning that up, but since it seems to revert to normal, am I right to suspect the real problem is something with the clutch itself?

[E Sully]

First take a look at the bottom of the transmission and see if the arms and springs look ok. It is cable operated and uses an omega spring for assist. If they are in good shape and adjusted to spec, and the cable is in good shape it will be time to look into other areas like the pedal cluster and the fork.

[Flat6pac]

The lever with the large spring is suposed to idle on the vertical shaft and they need to be lowered down and lubed. That doesnt cost any thing and takes about an hour.
There is a large story in the last month of a man and his problems with the helper spring and vertical shaft.
Bruce

[DRACO A5OG]

That actuator spring does not appear to be correct. It should be shorter and more stretched.

I would also remove the actuator and helper arm and see if the Helper arm slides out off the shaft. If rusted, you found the culprit plus that "suspect actuator spring. Clean both helper and shaft and place some HI-temp Lube and reassmbly.

Before putting the cable back on check the initial gap of the actuator that it is 1.2MM then with the cable on it is 1.0MM

Omega spring appears to be fine.

[gordner]

I am pretty sure that pic is for reference and is not the actual clutch with the issue.

[Tippy]

I wonder if your throwout bearing sleeve is dry?

[E Sully]

The photograph is not the OP's.
The spring in the picture is not the original, but the clutch works great.
As DRACO posted the gap at the set screw should be 1.2mm without the cable connected and 1mm with the cable on. Total travel of the arm when depressing the clutch should be 25mm. Adjustment of the cable travel is done at the pedal stop on the floorboard.

[jdbunda]

Thanks for all the suggestions. I will put it up on stands this weekend and see what's up.

[DRACO A5OG]

Originally Posted by gordner

I am pretty sure that pic is for reference and is not the actual clutch with the issue.

My Bad.

But John, definitely service the Helper Arm Shaft most neglect this simple maintenance. If your climate is a wet one, water will get up there and over time will rust and bind.

PM me if you get stuck.

Plus 1 on the T/O bearing guide tube if dry, it will bind as well. Someone posted using a can of spray wax and shooting it down the hole on top of trans to help lube the guide tube. I actually dropped my engine and trans and found my T/O bearing and Guide tube were shot, and yes Drier than the Sahara Desert. Replaced those and pilot bearing. Bonus no more annoying Clutch Rattle

Jim