Clutch

What a clutch kit includes

A clutch kit normally contains the pressure plate, which bolts to the flywheel and clamps the disc, the friction disc that splines onto the transmission input shaft, and often the release bearing, pilot bushing and an alignment tool. Some of the Centerforce items here are complete kits; others are a disc and pressure plate only, or a disc alone to pair with an existing Centerforce pressure plate. Read the contents line so you know whether to add a bearing and pilot from the Clutch Parts category. Clutch fork pivot balls and fulcrums for 1941 to 1975 Jeeps and Willys are also here, since the fork pivots on them inside the bellhousing.

Choosing a clutch by use

• Stock replacement: Centerforce Series I is built for stock engines and mild upgrades. It holds like the original with a factory-feeling pedal and is the right pick for a daily driven Toyota pickup or Nissan Pathfinder.
• Towing, big tires and moderate power: Series II adds a full-facing disc with premium friction material and a pressure plate with centrifugal weights that increase clamp load as engine speed rises, so pedal effort stays reasonable while holding power rises. It suits trucks that tow, run 33 inch and larger tires or have added torque.
• High torque and hard use: Dual Friction pairs a full 360 degree facing on one side with a segmented facing on the other, for more holding capacity and heat resistance with manageable engagement. Centerforce quotes up to 90 percent more holding capacity than stock on some applications. Engagement is firmer and these are meant for built engines, heavy off-road use and frequent towing.

Matching the parts

A clutch is matched to the engine, the transmission and the flywheel, not just the model. Diameter, spline count and input shaft diameter must agree with the transmission; the pressure plate bolt pattern must agree with the flywheel. Within one model line the clutch can change by year and engine, for example Toyota pickups with the 22R versus the 3.0 V6. Where a kit is listed as universal fit, it means Centerforce sells it by application and you must confirm the engine and transmission yourself. Centrifugal weight pressure plates are also sensitive to being installed with the flywheel surface at the correct height, so a flywheel that has been machined too deep may need a shim or replacement.

Installation

Resurface or replace the flywheel every time; a new disc on a glazed or heat-checked flywheel will chatter and wear quickly. Clean the flywheel and pressure plate faces with brake cleaner and keep grease off them. Install the disc the right way around, with the marking or the raised hub toward the transmission as the instructions show. Use the alignment tool to center the disc, then tighten the pressure plate bolts gradually in a star pattern to the specified torque so the plate seats evenly. Replace the pilot bushing and release bearing, lightly grease the input shaft splines and the fork pivot ball, and check the fork and bearing retainer sleeve for wear. New flywheel bolts and thread locker are good practice.

Clutch work means supporting a transmission that can weigh over 100 pounds and working under a vehicle on stands; if that is new to you, this is a job for a shop.

Break-in and adjustment

Most performance clutches want a break-in period of several hundred miles of normal street driving with no hard launches, so the friction surfaces seat against the flywheel and pressure plate. After break-in, check hydraulic fluid level and pedal free play or cable adjustment. A new clutch that slips when hot during break-in points to oil on the disc or a flywheel problem rather than a bad clutch.