Clutch Question
 

My '67 has a '79 350 and a '79 3 speed so I am going out on a limb and assuming it also has a '79 clutch.

Driving today I heard a "ping" sound, and the next time I pushed the clutch pedal in there was almost no feel at all until the clutch pedal was almost at full throw and the clutch was actuated. This is now the current state of the clutch pedal.

When I got home I felt along the top of the clutch pedal assy (under the dash) and found a small hole at the top of the clutch pedal lever. I also found a small hole on a metal assy forward (towards the firewall) of that. Obviously a spring COULD go there to pull the clutch pedal back into place. BUT, I found no spring in the cab.

Looking in an '80 - '87 repair manual I see that the clutch fork has a return spring. Looks to be down by the lever and shaft assy in the engine compartment about cab floor level, driver's side. There is also a retainer spring listed on the diagram. Both appear to be in place but I'm stuck until I get someone in the cab to depress the clutch while I look under the hood.

My gut feeling is that there is an unseen problem with the fork return spring. Any helpful comments out there?

Lobo'74,

There are two springs on the stock clutch setup on my '70 3spd. There is one under the dash, pictured here:

http://home.duracom.net/~pablo/1970/...70_Cspring.JPG

If you don't have one here, it may have flown up under the dash and hung on a wire or something, since it has hooks on both ends.

There is also one as your manual describes that hooks from the frame to the clutch fork, pictured here:

http://home.duracom.net/~pablo/1970/..._CspringUH.JPG

I believe the retainer spring you mention runs from the bottom z-bar arm to the clutch fork, keeping those two held together should the main spring fail. That way, you don't lose the adjustable rod. There's not one on my '70.

If the linkage is stiff, only one spring may not be sufficient to return the pedal.

Hope this helps...SSOW :bowtie:

It is possible a pressure plate spring let go & in trapped in between disc & plate, have seen it happen many times. Brian

I can feel exactly where the green spring you have pictured goes, but there is nothing there. Can't find the spring up in the dash . . . bet thats hard to do.

I will try to find a replacement for that spring and see if that fixes it. Great picture, thats just the one thats missing. The other one, down in the engine compartment is still in place.

Sure hope its not one of the pressure plate springs that let go. . . . What symptoms would that give me?

If a plate spring let go you will probably have a chatter effect when you engage the clutch.sounds like a spring launched out of place from the fork .

Pedal to the floor & the clutch is still engaged? Throwout bearing may have punched through the diaphragm spring fingers.

pressure plate spring
 

I had a pressure plate spring let go once and I couldn't disengage the clutch after that. had to drive it home using the starter in first gear to get going and then match the RPM's to get into the other gears.

Fixed . . . I think?
 

The two springs that go to the clutch fork are still in place. I put in a "universal" pedal return spring on the clutch pedal lever in the cab. There is not as much resistance as there was before all this started, but the clutch still functions normally. No funny noises, no slipping, etc. In the clutch pedal I can feel other springs actuating near full throw. My guess is that the replacement "universal" pedal return spring is weaker than the original and as such allows the feel of the two springs on the clutch fork to be felt.

Clutch pedal feels weaker than it used to, but as I said, no noises or clutch slipping.

Its a mystery to me.

Lobo'74,

Good news...I hope that turns out to be the only problem. BTW, I've found that as the linkage wears in these trucks, the rod that goes through the firewall often starts to bind, either against the rubber boot or the firewall itself. You can often help things out by removing the rod and tweaking it a little in a vise (no heat required) until it moves through full travel without binding. Add a little grease to the other joints & pins, and it's smooth for another few years.

SSOW... :bowtie: