For those of you using hydraulic throw out bearings, most mfgrs
recommend a pedal stop to prevent the clutch from over centering.
This is not a problem with stock systems, but the HD throw out bearings
are generic in application & accommodate many different engine/tranny
combos with the same basic unit. The possible problem is this: because
the throw of the HD bearing may be longer than required, you may be able
to force the pressure plate fingers beyond the mid point where they will
not return. At this point you have an in-operable clutch at best,
possible engine failure as a worse case.
My McLeod bearing comes with installation instructions that include a
requirement that you install a pedal stop. Years ago, when I installed
the HD bearing in my roadster, I bent up some sheet metal, added a large
bolt & 2 nuts, & screwed this to the firewall to provide an adjustable
stop that would contact the forward edge of the clutch pedal. OK, but
kind of clunky.
I remembered today, that I had never installed a stop in the GT, but I
didn't feel like spending a lot of time up side down under the dash like
the last time, so I decided to look at the other end of the pedal. I
have a late model chutch/brake set up with a brake booster, but the
following should work with the early set up as well. First, off with the
cover, & study the pedal travel with the return spring removed. See the
big clevis fork? That is the thing to stop. Easy. Remove the top bolt
securing the clutch master to the pedal box, replace it with a piece of
threaded rod the same size, 5/16", about 3" long, nut & lock washer on
the back, nut on the front, tighten well. The rod protrudes forward
inside the pedal box. Out of the scrap pile comes a piece of 3/16" steel
plate, cut down to 1-1/4" x 2", your measurements may vary. Drill a hole
11/32" centered, about 1/2" from one end. This is where it will go onto
the threaded rod. Eyeball & mark where the clevis rod would pass through
the plate if it was on the rod, & drill another hole about 1/4" from
your mark, closer to the first hole. Two cuts with a hack saw & you have
a slot from the bottom of the plate to the second hole. Clean all the
cuts/ holes with a file to remove burrs, rough edges.
Install the plate on the threaded rod with the slot around the clevis
rod, nut first, lock washer, plate, 2nd nut. Only thing left is
adjustment. Start out with the plate allowing a small amount of pedal
movement. Parking brake on, start the engine, see if the clutch will
allow engagement of any gear. Increase the pedal travel by moving the
plate until you can just engage reverse without any grind, then move the
plate about 1/2 a turn of the nut further as insurance. Now, no matter
how hot you are running the autocross course, you will not over
disengage the clutch, even if you don't get low time of the meet. After
a few days of driving, re-check the setting by reducing travel, just to
be sure. At this point, I recommend replacing the lock washer, or adding
some lock tite. Remember, lock washers are one-time use.
Jim Stuart
|