ACT 12-18 Jeep Wrangler JK XACT Flywheel ProMass
ACT 601060 is the XACT Pro-Mass flywheel for the 2012-2018 Jeep Wrangler JK and JK Unlimited with the 3.6L Pentastar V6 and the NSG370 six-speed manual. It is built for owners who crawl rocks, run big tires or tow, and who want a flywheel that carries the engine over obstacles instead of stalling it. If your JK clutch job is coming up because of slip, chatter or a scored flywheel face, this is the flywheel ACT pairs with its heavy duty JK clutch kit.
Most performance flywheels are about losing weight so the engine revs faster. The Pro-Mass goes the other way. ACT says it was developed with greater inertia for better climbing and pulling, with the mass placed where it adds the most momentum for the least weight. On the trail that means the engine is less likely to bog or stall when a tire hits a ledge at idle speed in low range, and it is easier to pull away with a heavy trailer or 35-inch tires.
The flywheel is a one-piece forged chromoly steel part, CNC machined and computer balanced, with an induction-hardened ring gear. ACT lists it at 44 lb, with an 11 inch (280 mm) friction surface and a 127-tooth ring gear, and it is SFI 1.1 certified. Because it is one piece, ACT notes there is no dual-mass section to wear out, no loose ring gear and less gear rattle, and the solid casting acts as a heat sink for the clutch. It can be resurfaced like a stock flywheel.
A flywheel is checked once the transmission is out. Look for hot spots, cracks running from the rivet holes, and a friction surface that is out of flat. If the face is only lightly glazed, resurfacing may be enough; if it is cracked or beyond the machining limit, replace it. With the clutch still in, chatter from a warm clutch, a high engagement point and slip under load all point to the clutch assembly, so plan the flywheel and clutch as one job. Our Wrangler JK and JL transmission service guide covers the drivetrain checks, and the slipping diagnosis guide explains the load test.
ACT lists the 601060 for the 2012-2018 Jeep Wrangler JK, two-door and Unlimited, including Sport, Sport S, Sahara, Rubicon and Willys Wheeler trims, all with the 3.6L V6 and the manual transmission. It does not fit the 2007-2011 JK with the 3.8L engine, automatic Wranglers, or the 2018-and-later JL. Compare the ring gear tooth count and bolt pattern with your old flywheel, or send us your year and VIN to confirm. ACT shows this flywheel as the matching option for its JP4-HDSS heavy duty JK clutch kit. More Jeep drivetrain parts are on our Wrangler JK and JL page.
If you would rather buy a clutch and flywheel package from one brand, compare the McLeod Trail Pro kit for the same 2012-2018 3.6L JK.
| Brand | ACT |
| Part number | 601060 |
| Fits | ACT 12-18 Jeep Wrangler JK XACT Flywheel ProMass |
| Vehicle fitment | Jeep Wrangler Jk Xact (2012-2018) |
| Type | Flywheels |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. ACT lists it for the 2012-2018 JK with the 3.6L Pentastar V6 and manual transmission. The earlier 3.8L trucks use different parts.
It is a Pro-Mass design. ACT adds inertia so the engine carries momentum over obstacles, pulls big tires and tows without stalling. ACT lists it at 44 lb.
ACT shows it as the matching flywheel for its JP4-HDSS heavy duty off-road street clutch kit for the 2012-2018 3.6L JK. Any clutch you use must match the 11 inch (280 mm) friction surface.
Yes. ACT says XACT flywheels resurface like stock ones. Remove no more than 0.040 in (1.02 mm) and keep the correct step.
ACT says its one-piece design removes dual-mass parts and gives no gear rattle. Actual noise also depends on the clutch disc and gearbox condition.
No. The 2018-and-later JL uses a different engine and transmission setup and needs its own flywheel.
