Mysterious Clutch Problem

The most common problem with the clutch cable, that I am aware of, is lubrication, it should be lubricated with oil and not grease, as grease will cause it to bind and will cause problems in cold weather. The engine may be warm but there is very littlle warming the cable. Next I should make sure that the mechanical movement of the actuating lever is not impeded. If all of that is O.K. Check the the thrust bearing and on to the clutch plate and pressure plate. It is not that bad of a job on a Dino. Hopefully its the cable movement.

 

Water in the cable. Freezes. See if you can blow some oil through cable. I had to change my cable about 15 years ago. Had gotten rusty and would bind. Millions of little balls in there and they have to roll. Pulled it apart and was a mess. Don't know how water gets in there but it did. I now run some 3 and 1 oil down cable from head end. Couple of times a year. No problem since.

 

I snapped a clutch cable due to water freezing inside the cable also. Double check the rubber gaiters at each end. Water may get in from engine washing and collects at the lowest point where it can freeze and bind the cable.

 

Dinodan -

The good news is that the clutch pedal, cable, and actuator system is mechanically simple. The bad news is that your difficulty cannot be diagnosed without a stepwise approach to each member of the system. Sorry guys, but I don't think ice will lead to failure. I suspect the cold weather is merely coincidental.

The cables fail. The failure is rarely catastrophic, more often simply rust that attacks the inner workings (as John suggested, many balls, much surface area to rust, long steel cable subject to rust). The failure manifest itself as rough movement of the pedal, scratchy movement of the pedal, clicking, sticking, etc. Imagine some rusty ball bearings running along the channel of the flat cable. Kind of like grinding your teeth on beebees.

The helper spring mounted on the forward cam cover is the second culprit to chase down. It might be as simple as the spring coming loose, or the the pivot pin having been worn beyond function.

The 3rd troublemaker is the actuator arm riding on the ball and socket joint within the bell housing.

And finally, the pressure plate itself (many fingers, much spring tension).

I would first eyeball the helper spring to see if everything appears correct. This is simple.

Second, I would disconnect the clutch cable from either end - whichever you find easiest. This depends on whether you have a lift. Once one end is disconnected, you can move the cable by hand or foot in the sheath and feel whether the action is smooth. If it is smooth, then the problem is not the clutch cable.

When the cable is disconnected, you can remove the helper spring from its mount, which will take the tension off of the actuator arm. Move this as much as you can with you hand to feel its action. You will not be able to press the pressure plate in by hand, but may be able to hear noise coming from within the bell housing that might give you a hint.

That the problem occurred and then corrected makes me want to suggest that the helper spring is not well mounted and rocking on a loose bolt. Check this first.

Jim S.

 

I lubricate it with TriFlow.

There was a post a while back on a restoration where the owner recommended soaking the clutch cable in a solution to clean the ball bearings (sorry, I forgot the cleaner they listed, but somewhat recall it was ATF).

 

ATF would certainly clean it out, somehow I think, as John said, 3 in 1 or similar oil would be preferable. I use an old motorcycle cable oiling system; partially fill a ballon with oil and tie the "mouth" over the open cable end, the squeeze the baloon gently and wash the old oil out the other side.