ACT 2011 Ford Mustang XACT Flywheel Streetlite
The ACT 600670 is an XACT Streetlite flywheel for the Ford Mustang with the 3.7L V6 and a manual transmission. Our listing is for the 2011 car, the first year of the 3.7L, and ACT catalogs the same part through 2017. Buyers usually find it while replacing a slipping clutch and deciding what to do with a heat-checked or warped factory flywheel, or when they want the V6 to rev more freely between shifts.
The flywheel bolts to the back of the crankshaft and does three jobs: it carries the starter ring gear, it provides the friction surface the clutch disc clamps against, and its mass smooths engine pulses at low speed. On the 2011-up V6 car it sits ahead of the 6-speed manual. A lighter flywheel lets the engine gain and drop RPM faster, which makes rev-matched downshifts easier and the car feel more responsive.
The 600670 is forged from chromoly steel, heat treated, CNC machined and dynamically balanced. ACT lists it at 20.5 lb with an 11 in (280 mm) friction surface and a 164-tooth induction-hardened ring gear, built as one piece so there are no inserts to warp or ring gear to come loose. ACT describes the Streetlite as considerably lighter than stock and its most durable flywheel, rated SFI 1.1, recommended for street and drag use. Expect noticeably quicker throttle response and anywhere from factory-level to mild gear rattle at idle.
Pull the transmission and inspect the face with a straightedge and feeler gauge. Light glazing usually machines out; cracks and deep hot spots do not. Our resurface vs. replace page covers the call. If you are chasing a slip, confirm the clutch is the cause first with our slipping diagnosis guide, and read lightweight vs. stock flywheel if you are unsure the lighter feel suits how you drive.
ACT lists 600670 for the 2011-2017 Ford Mustang 3.7L V6 with a manual transmission, including V6 and ST trims. Our listing is titled for 2011. It does not fit the 5.0L GT, the Shelby, the 2.3L EcoBoost or the 2005-2010 4.0L V6. When replacing a flywheel, ACT says the step, ring gear tooth count, thickness and ring gear offset must match the application, so if your car has a swapped engine or a non-stock clutch, send us the year and VIN and we will confirm. More parts are on our hard parts page.
Prefer aluminum? The SPEC SF37A aluminum flywheel is the lighter alternative for the same engine. For 6-speed gearbox issues found during the job, see our Mustang MT82 problems page.
| Brand | ACT |
| Part number | 600670 |
| Fits | ACT 2011 Ford Mustang XACT Flywheel Streetlite |
| Vehicle fitment | Ford Mustang Xact (2011) |
| Type | Flywheels |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
ACT lists it for the 2011-2017 Mustang 3.7L V6 with a manual transmission. Our listing is titled 2011, so send us your VIN for a later car and we will confirm.
No. It is made for the 3.7L V6 only. The 5.0L GT, Shelby and 2.3L EcoBoost use different flywheels.
ACT lists the 600670 at 20.5 lb. It is a chromoly Streetlite, which ACT describes as considerably lighter than stock while being its most durable flywheel design.
Yes. ACT includes the flywheel bolts (M10-1.00 x 25 mm).
Yes. ACT notes that the vehicle manufacturer recommends the misfire monitor neutral profile correction procedure after a flywheel replacement. A shop scan tool can run it.
Yes. ACT says it can be machined like a stock flywheel, removing no more than 0.040 in and keeping the correct step.
