DIY Hillbilly Clutch Slipper...
What is the "Hillbilly Clutch Slipper"?..
How does it work?...
How is it adjusted?...
...Just a simple, commonly available, hydraulic storm door closer cylinder installed on the clutch pedal. It allows tuning a bit of "slip" into the clutch's initial engagement, damping the peak shock loads as power is being transmitted to the rest of the drivetrain. It's adjustable for exactly where in the pedal travel that it becomes active, and adjustable for rate of release from that point on (it controls slip only during the final part of engagement). The cylinder is hydraulic (not pneumatic like most door closers), with characteristics similar to those of a 90/10 shock, pulling the rod out is easy, only the return stroke of the cylinder is controlled. With the cylinder installed on a clutch pedal, only the final bit of clutch pedal's release is delayed, not the whole release cycle. The rest of the clutch pedal's travel works without interference. During normal driving you will not even know it is there...no detectable difference in clutch feel. If you are using the clutch pedal during shifts, the slipper will soften drivetrain shock during gear changes as well.
...Basically when the clutch pedal is depressed, it pulls the rod out of the cylinder. When released, the clutch pedal comes out unrestricted until the nuts on the cylinder's shaft contact the dash bracket. From that point, the rate of release is controlled by the adjustable orifice inside the cylinder.
...Adjusting the nuts on the threaded portion of the shaft changes the point in the clutch pedal travel where it's release is delayed. From that point, turning the dash knob changes the speed of the pedal's final bit of release. There are 10 turns of adjustment on the knob. At "0" turns the pedal is delayed very little, barely noticable. At "10" turns, the pedal takes about a minute to return. Typically, the rate of release is usually set somewhere between 2-1/2 and 7 turns.
A simple bracket was fabricated and tack welded to the clutch pedal...
It's affordable too...
...The only change made to the $12 hyd cylinder is to add a section of 5/16" all-thread to the end of it's shaft. This setup works on both mechanical and hydraulic clutch linkages, as it directly attaches to the clutch pedal itself.
Below are some pics of the parts we used, you can probably find them at your local hardware store...
...Wright Products VH440BL medium duty door closer
...Hilman 881357 bar knob (5/16" x 18)
...5/16 x 18 "all-thread" (comes in 3' lengths)
...5/16" x 18 flange nut
...5/16" x 18 jam nut
...Delrin plastic (for making the dash bracket slide bushing)
above items likely less than $20 at your local hardware store.
The VH440BL actually comes with attachment brackets that could be modified for use on a clutch pedal, but we made the bracket that attaches to our clutch pedal from scratch.