Exedy 1996-2016 Ford Mustang V8 Lightweight Flywheel (6 Bolt)
The Exedy EF503A is the 6-bolt version of Exedy's lightweight chromoly flywheel for modular V8 Mustangs. It is the part GT, Mach 1, Cobra and Bullitt owners look for when the stock flywheel shows heat cracks, has been cut too many times to resurface again, or makes a fresh clutch chatter on takeoff. It also suits owners who want a quicker-revving engine for drag strip, autocross or road course days without giving up street manners.
Bolted to the back of the 4.6L crankshaft, the flywheel carries the starter ring gear, gives the clutch disc its friction face and stores rotating energy that smooths the engine's pulses at low rpm. The EF503A is machined from one piece of billet chromoly steel with the ring gear teeth cut into the flywheel itself, so there is no pressed-on gear to walk loose. Exedy describes its lightweight flywheels as SFI approved and engineering tested to 15,000-18,000 rpm. Exedy lists a 16.1 lb weight.
Shedding mass lets the engine pick up and drop rpm faster, so downshifts rev-match sooner and the car pulls harder between gears. The trade-off: launches need a bit more throttle and you may hear more gear rattle at idle.
A flywheel is judged once the transmission is out: look for cracks and heat checking, check runout and thickness, and inspect the ring gear. Before pulling anything, rule out the cheaper causes. Our clutch chatter on takeoff guide covers engine mounts and contaminated discs, and flywheel resurface vs. replace explains when a cut is still worth it. If you are weighing a lighter part against stock, read lightweight vs. stock flywheel pros and cons first.
Our listing title reads 1996-2016 Mustang V8. Exedy's own application list for EF503A covers the 1996-2010 Mustang GT, the 1997 Cobra, 2003-04 Mach 1 and 2008-09 Bullitt. The key detail is the crankshaft flange: modular V8s were built with both 6-bolt and 8-bolt flanges, and this flywheel is the 6-bolt part. Count the bolts on your current flywheel. If you see eight, you need the Exedy EF502A 8-bolt flywheel instead. Owners of 2011-up 5.0L cars should confirm the bolt count before ordering. Ring gear and clutch diameter also need to match your clutch kit, so send us your year, VIN and clutch part number if you are unsure. More drivetrain parts are in our hard parts collection.
| Brand | Exedy |
| Part number | EF503A |
| Fits | Exedy 1996-2016 Ford Mustang V8 Lightweight Flywheel (6 Bolt) |
| Vehicle fitment | Ford Mustang V8 Lightweight (1996-2016) |
| Type | Flywheels |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
EF503A is the 6-bolt version. Exedy sells EF502A for 8-bolt cranks. Count the bolts on your current flywheel before ordering.
Exedy lists the 1996-2010 Mustang GT, 1997 Cobra, 2003-04 Mach 1 and 2008-09 Bullitt. Our listing title says 1996-2016, so 2011-up owners should confirm bolt count or send us the VIN.
Exedy lists 16.1 lb. It is one-piece billet chromoly steel with the ring gear integrated.
Exedy states its lightweight flywheels are SFI approved, which is the certification most tracks check for.
New flywheel bolts, the pilot bearing, the release bearing and usually the clutch itself. Check the rear main seal while it is exposed.
The engine revs up and down faster. Takeoffs need a little more throttle and idle gear rattle may be louder than stock.
