Spec 07-09 Toyota FJ Cruiser/05-06 Toyota Tundra Stage 2 Clutch Kit

A manual FJ Cruiser or V6 Tundra that has been lifted, geared, loaded with armor or hitched to a trailer works its clutch far harder than Toyota planned. The usual complaints are slip on a long grade with the throttle pinned, a smell of hot friction after rock crawling, judder when backing a trailer up a ramp, and a pedal that chirps or growls when you push it. SPEC ST912 is SPEC's Stage 2 kit for these trucks, built for owners who want more holding power without giving up a clutch that is easy to live with in traffic.

What the Stage 2 clutch kit does in an FJ Cruiser or Tundra

In these trucks the clutch is a single dry plate squeezed between the flywheel on the V6 crankshaft and a diaphragm pressure plate. When the pedal is up, the diaphragm clamps the disc and every bit of engine torque flows through it into the manual gearbox. Larger tires and heavier loads raise the torque the disc must hold at low speed, which is exactly where a worn or stock disc gives up first.

SPEC rates ST912 at 491 ft-lb of torque capacity. SPEC describes its Stage 2 friction as a Kevlar disc with steel backing, chosen for drivability, long life and higher torque capacity than the organic Stage 1. For comparison, SPEC lists its Stage 1 kit for the same trucks at 430 ft-lb and its Stage 2+ at 551 ft-lb, so ST912 sits in the middle: a solid step over stock for a built trail truck or a tow rig, while keeping engagement predictable. SPEC lists the kit's shipping weight at 25 lb.

Symptoms that point to a worn clutch

• Engine rpm rises without a matching gain in speed, worst in the higher gears on a hill or with a trailer
• Burning friction smell after low-range crawling, launching a boat or slipping the clutch on obstacles
• Shudder or chatter as the clutch takes up from a stop
• Whine, chirp or growl that changes when the pedal goes down, typical of a dry release bearing
• Gears that grind or are hard to select, which can come from the clutch not releasing fully
• Engagement point creeping higher on the pedal as the disc wears thin

How to confirm before you buy

Warm the truck up, select a high gear at low speed and roll into full throttle. If the tachometer jumps ahead of road speed, the disc is slipping. Before you blame the clutch for poor release or grinding, check the hydraulic fluid level and look for leaks at the master and slave cylinders, since a soft or sinking pedal is a hydraulic fault, not a friction one. Also look for oil dripping from the bellhousing; a leaking rear main or input seal will contaminate a new disc quickly, so fix the leak during the job. Our slipping diagnosis guide walks through the road test, and flare versus slip explains how to tell a true slip from other drivability problems.

Fitment

Our listing title covers the 2007-2009 FJ Cruiser and the 2005-2006 Tundra. SPEC catalogs the same ST912 kit more widely: the FJ Cruiser 2007-2014, the Tacoma 4.0L including the X-Runner 2005-2015, and the Tundra 2004-2006. It is for manual-transmission trucks only. The FJ and Tacoma applications are the 4.0L V6; Tundra owners with a 2004 truck in particular should send us the year and VIN so we can confirm the engine and gearbox before shipping. Match part number ST912 on the box, and if your truck already has an aftermarket flywheel or a non-factory clutch, tell us what is fitted.

If you would rather go back to stock friction on a Tacoma V6, the Exedy OE Tacoma V6 kit is the factory-style option, and the Exedy Stage 2 cerametallic 6-puck kit is a more aggressive alternative for heavy use.

Install notes

• A flywheel is not part of the kit. Have the original surfaced or replace it; SPEC offers steel (ST91S) and aluminum (ST91A, 18 lb) flywheels for these trucks.
• Replace the pilot bearing and inspect the release fork pivot and input shaft splines while the transmission is out. A light film of high-temperature grease on the splines and fork contact points is all they need.
• Center the disc with an alignment tool. If the one in the box goes missing, our universal clutch alignment tool kit uses expanding spindles that adapt to most disc hubs and pilot bearings.
• Snug the pressure plate bolts in a star pattern a few turns at a time, then torque to the factory specification.
• Bleed the hydraulics with the brake fluid type printed on the reservoir cap.
• Break the clutch in with several hundred miles of gentle driving before towing or trail use so the Kevlar facing beds in evenly.

Weighing a clutch job against other driveline work on a high-mileage truck? Our repair cost guide sets expectations.

Does ST912 fit a 2010-2014 FJ Cruiser?

SPEC catalogs ST912 for the manual FJ Cruiser from 2007 through 2014, even though our title lists 2007-2009. Send us your year and VIN and we will confirm before it ships.

Will it fit my Tacoma 4.0L?

Yes. SPEC lists the same kit for the 2005-2015 Tacoma 4.0L with a manual transmission, including the X-Runner.

How much torque does it hold?

SPEC rates ST912 at 491 ft-lb. Their Stage 1 kit for these trucks is rated 430 ft-lb and the Stage 2+ is rated 551 ft-lb.

Is a flywheel included?

No. Resurface your original flywheel or fit a new one. SPEC makes steel ST91S and aluminum ST91A flywheels for this application.

Is a Stage 2 clutch too grabby for a daily driven truck?

SPEC builds its Stage 2 with a steel-backed Kevlar disc aimed at drivability and long life, so it is meant for street use. Expect firmer engagement than stock, but not the on-off feel of a puck race disc.

What fluid does the clutch hydraulic system use?

These trucks use brake fluid in the clutch hydraulics. Use the type printed on the reservoir cap and bleed the slave cylinder after the install.

• How to Diagnose Transmission Slipping
• Shift Flare vs. Slip: How to Tell Them Apart
• Automatic vs. Manual Transmission Repair Cost