When Camaros were rolling off assembly lines in California and Ohio a half-century ago those fitted with manual transmissions had a simple equalizer shaft and pushrods for clutch release. It took a lot of pedal effort to release the clutch and shift gears, especially if you had a stiff racing clutch. Fifty years later, there’s a better way.
It has long been said you can move the world with the power of hydraulics—using fluid under pressure to do the hard work for us. Silver Sport Transmissions (SST) understands the benefits of hydraulics and has applied it to a very effective clutch release system for your classic Chevy. The PerfectFit hydraulic clutch kit from Silver Sport Transmissions takes the power of hydraulics and puts it to work for you. You will never have a better shifting experience once you make the switch to hydraulics.
We’re installing the PerfectFit hydraulic clutch system and a TREMEC Magnum six-speed in a 1967 Camaro, but the process is similar for almost any Chevy. The PerfectFit system lives up to its name, allowing you to infuse modern technology into a classic Camaro. Silver Sport Transmissions provides everything you’re going to need to install both the TREMEC Magnum six-speed and the hydraulic clutch system. So let’s head over to Best of Show Coachworks in Escondido, California, to see what’s involved in installing the SST kit.
The TREMEC Magnum six-speed is based on the design of the OEM TR-6060 and focused on the aftermarket with multiple shifter positions and higher torque capacity. The Magnum six-speed has two overdrive gears, which offer you a choice when you’re on the open road. Silver Sport Transmissions (SST) offers their parts as kits or a la carte if you don’t need items like the transmission or a crossmember.
The first order of business with our SST installation kit is installing the flywheel. This is the 168-tooth (PN FWG-460535) LS Steel Billet Flywheel made in the USA. Use Permatex Threadlocker on the bolts and torque them in a star pattern to 74 ft-lb. We’ve opted for a heavy-duty clutch pilot bearing (PN PBG-57080) for this application because we want smooth operation. Although a pilot bearing costs more than a bushing, you will get smoother function and durability.
With the flywheel contact surface cleaned with brake cleaner and allowed to dry, a clutch alignment tool is used to correctly position (center) the 26-spline input clutch disc.
We’ve opted for a Ram Powergrip 11-inch clutch from SST. This is a true dual-friction clutch with both an organic and segmented ceramic plate. With a 550–lb-ft torque capacity, this clutch delivers light pedal effort with smooth engagement. With the clutch disc centered, mount the pressure plate and install the bolts with a dab of Permatex Threadlocker. The bolts get torqued in a star pattern to 52 ft-lb. First, snug the bolts to uniformly seat the pressure plate, and then tighten to the final torque spec.
After installing our SFI-rated Quick Time spun-steel bellhousing (PN BHGP-RM8020), we measured from the bellhousing-to-transmission mating surface to the clutch diaphragm. We’re measuring from the mating surface to where the ruler touches the clutch diaphragm. Note the exact measurement. Because the clutch release slave is a constant duty cycle bearing, it should be solid against the clutch diaphragm, however, with the clutch firmly engaged.
SST’s hydraulic clutch kit is original equipment specification installed in new vehicles. What this means for you is durability and ease of installation. The clutch slave release bearing is rated at 7,000 rpm, has a forged aluminum housing, silicone dust boot, piston wiper seals, and a one-million-cycle service life. You also get the Wilwood clutch master cylinder, billet adapter, and adjustable clutch rod.
The clutch slave cylinder will mount on this bolt-on pad at the front of the Magnum. Shims are available to adjust the slave as far forward as necessary. The slave gets its hydraulic pressure from a clutch-pedal-activated Wilwood master cylinder.
A diaphragm clutch requires constant contact with the release bearing to function properly. If there’s no contact, you will experience excessive clutch pedal travel and an insufficient release. If the contact is too tight, the clutch may never fully engage and will slip. So, to make sure we get it right we need take another measurement.
With the clutch concentric slave fully compressed, measure from the bearing to the transmission’s front mating surface and record the number. This should put the slave against the clutch diaphragm when the transmission and engine are mated. It is important to get the dimensions within the manufacturer’s specifications because as the clutch disc wears, the fingers will extend toward the transmission, causing the clutch to slip if the bearing isn’t shimmed properly.
If you’re converting your Chevy from an automatic, you’ll need the brake and clutch pedals from SST (PN PHG-PT-1).
The Wilwood clutch master cylinder is a simple firewall bolt-on thanks to the billet adapter designed for the Camaro’s firewall. This is a nice looking piece that offers fluid function and smoothness.
This illustration shows proper clutch master cylinder installation. The reinforcement plate, which is also used as a template, is located behind the firewall. The Wilwood master cylinder is tied to the clutch pedal via this adjustable rod with Heim joints at each end. This is a simple bolt-on and adjustable piece. It’s imperative that the rod push as straight as possible into the master, so use the correct hole on the clutch pedal.
Center the clutch master cylinder approximately 1/2-inch below the pedal support stud (arrow). Some applications will have a clutch pedal rod hole in the firewall capped off, but not all. Center punch the bolt holes as shown here for drilling.
SST suggests an approximately 1 3/4-inch hole be bored in the firewall for clutch rod access. This ensures adequate clearance and master cylinder fit. As stated, some firewalls will already have a hole present from the factory.
Drill the mounting holes using a 3/8-inch drill bit. Begin drilling with smaller pilot holes and work your way up.
This is the reinforcement plate, which actually goes on the inside of the firewall to strengthen the clutch master mounting assembly. We’re using it as a template to make sure everything lines up.
The clutch master cylinder has been mounted using the reinforcement plate inside along with the pushrod connected inside to the clutch pedal. We also installed the clutch master cylinder pressure line, which goes to the slave at the transmission
The pressure line runs down below to the slave at the transmission. Here you can see how it passes through slots in the transmission and the bellhousing to reach the slave. You can also see the bleed port that SST added to make bleeding the system easier.
You have a couple of hydraulic clutch master cylinder reservoir options from SST, ranging from inexpensive OE plastic all the way to show-ready billet like the Ringbrothers piece shown. The reservoir must be located above the clutch master cylinder and easy to access. Conventional DOT 3 brake fluid is used just like you use with your brakes.
The completed hydraulic clutch conversion is virtually invisible when located next to the Wilwood disc brake master cylinder. Note the reservoir location high on the firewall, to the left of the brake master, for easy access and gravity feed.
Photography by Steven Rupp