Clutch pedal adjustment?

[Number21]

Excuse me if this is a stupid question...but my '79 C30 with 350/4 speed is my first manual. I don't know how it's "supposed" to feel, but I think the travel in the clutch pedal is excessive and so is the amount of pressure required to push it. After a short drive it makes the arthritis in my knee hurt.

After looking under the truck I can see the return spring - one end is attached to the pedal, the other is just hooked over a bolt on the exhaust manifold. Where is the return spring supposed to hook up to? And can I replace it with a weaker spring?

Also, there looks to be an adjustment for the amount of travel for the pedal...can anyone tell me what the correct procedure for adjusting it is?

[James McClure]

21,OK. First is "feel", it's subjective. Excessive depends on the driver. It should operate smoothly without binding, sticking or chattering. Know this though, the stiffer it is the more linkage wears. The return spring you see is only there to keep the linkage from pushing against the pressure plate and to keep a preload on the linkage. Spring should attach to linkage at the release fork and go to the frame. You can use a weaker spring if you wish. Free travel should be 1 to 2" at the pedal from it's rest position to when it first starts to release clutch. The longer the rod the higher the pedal will be and the smaller the free travel. Let us know how you do, jim

[68 TT]

That spring isn't the part giving you all the pedal pressure it is the actual pressure plate on the clutch.

That spring is just there to keep the rod engaged with the clutch fork.

Mine is connected to a point on the frame rail across from the exhaust manifold exit.

I can take a picture of it if you want.

[68 TT]

I have bad knees as well so I have taken to dropping it into neutral when slowing down and while sitting at lights just to take the load off my knees.

Mine has 5.13 gears in it so I am shifting a whole lot so every bit of relief for my knees is welcome even if it is at the expense of my brakes.

I plan on installing the 4L80E automatic I have here after I finish gathering all the parts I need for the conversion.

[72 CustomCamper]

There is also a heavy spring under the dash that keeps the clutch petal from rattleing around. I've removed this spring a few times and it helped with the amount of pressure to depress the petal a little bit. These trucks usually have stiff pressure plates though...


Chuck

[Number21]

Originally Posted by James McClure

Free travel should be 1 to 2" at the pedal from it's rest position to when it first starts to release clutch.

Ahh...that should help! Right now I'd say the complete travel is about double the brake pedal and the clutch doesn't start to release until more than half way through...

Originally Posted by 68 TT

Mine has 5.13 gears in it so I am shifting a whole lot so every bit of relief for my knees is welcome even if it is at the expense of my brakes.

Ouch, I thought my 4.56's were bad! I'm definately leaning towards an auto swap. I just have a bad feeling I'm going to get reverse and first mixed up in a bad place....

I'll try and tinker with it a little more tonight and see what I can break. It's hard to post questions when your computer and truck are parked 10 miles apart....

[ironroad9c1]

Originally Posted by 68 TT

I have bad knees as well so I have taken to dropping it into neutral when slowing down and while sitting at lights just to take the load off my knees.

That is what you should do anyway, Brakes are cheaper that rebuilding the transmission and it saves wear on the throwout bearing, Downshifting is really only useful in racing a emergencies.

[lilpoindexter]

Originally Posted by Number21

E I think the travel in the clutch pedal is excessive

Me too... thhis is why I'm going to a hydraulic linkage someday

[Big Port Jimmy 6]

It probably has one of the "long" style three finger pressure plates in it. They always take more effort to release. I have had good luck in the past in changing to a diaphragm style pressure plate and the are smoother and have a lighter action with the same holding power. Jay

[man7sell]

Very interesting, my new 74 has a heavy clutch pressure too. It seams to engage and release after a couple of inches of travel. Total travel seams to be a lot from up to floor.

[James McClure]

Man7, read my post above, #2 I believe. Also read about changing pressure plate style to diaphram type. Also, it might be a good idea to learn how to shift without using the clutch. I drove 18 wheelers for years and not using the clutch is second nature.

[man7sell]

Originally Posted by James McClure

Man7, read my post above, #2 I believe. Also read about changing pressure plate style to diaphram type. Also, it might be a good idea to learn how to shift without using the clutch. I drove 18 wheelers for years and not using the clutch is second nature.

Good point James, road raced without using the clutch except for starts

[tucsonjwt]

Under the truck, there is a threaded rod with a wave washer and nut which should be adjusted. It determines, to some extent, the point at which the clutch engages. I have about 1" of thread showing past the nut. I once thought I needed a new clutch when I could not easily get into gear, but I just needed to tighten that nut and all was well. The nut sometimes works down the threads and may need to be adjusted occasionally. I have a weak knee also but I don't find the mechanical clutch to be a problem - not as easy as an hydraulic clutch but I would not consider it stiff at all. A lighter spring will help, but may not be strong enough to hold up under repeated use.