ACT 12-18 Jeep Wrangler JK HD-O/Perf Street Sprung Clutch Kit
ACT JP4-HDSS is a heavy duty clutch for the 2012-2018 Jeep Wrangler JK with the 3.6L Pentastar V6 and the six-speed manual. Owners usually go looking for it when the original clutch starts slipping on the highway with bigger tires, chatters crawling over rocks, or the pedal engagement point has crept to the top. It keeps a smooth organic disc, so the Jeep still drives like a daily, but adds clamp load for regeared, lifted and loaded rigs.
The 2012-2018 JK manual is the NSG370 six-speed, and the clutch sits between the Pentastar's flywheel and the NSG370 input shaft. Oversized tires and heavy armor multiply the load on that clutch, especially when starting off on a grade or in low range. JP4-HDSS uses ACT's J013 Heavy Duty pressure plate, whose diaphragm is heat treated in four stages to increase clamp load and reduce deflection, with the 3001111 Performance Street sprung disc. The disc is a large 280 mm (11 in) organic unit, steel-backed for burst strength, with a sprung center to soak up driveline shock. ACT rates the kit at 479 ft-lb at the crank, 21 percent over the factory clutch, on a 1.125 in input spline.
ACT describes the feel as light to moderate pedal effort, smooth positive engagement, OE to mild gear rattle and good drivability, and recommends it for street or off-road use. That modest increase over stock is deliberate: it holds the extra load from tires and gearing without turning the pedal into a leg workout on the trail.
Check the clutch hydraulics first: a low or contaminated reservoir or a weak release cylinder can cause drag and poor engagement that look like a failed clutch. Then test for slip in sixth at low rpm with firm throttle. Rule out gearbox issues as well; the NSG370 has its own known wear points and needs a 75W-85 GL-4 lube, not GL-5. Our Wrangler JK and JL transmission service guide covers the NSG370 fluid spec and weak points, and the slipping diagnosis guide explains how to read rpm against road speed.
ACT lists JP4-HDSS for 2012-2018 Jeep Wrangler JK with the 3.6L V6 and manual transmission, including Sport, Sahara and Rubicon and the four-door Unlimited versions. It does not fit the 2007-2011 JK with the 3.8L, and it does not fit the 2018-up JL, which uses a different manual gearbox. 2018 was a split year when both JK and JL were sold, so confirm the body style and send us your VIN if you are unsure. The McLeod Trail Pro kit is another option for the same 3.6L JK.
| Brand | ACT |
| Part number | JP4-HDSS |
| Fits | ACT 12-18 Jeep Wrangler JK HD-O/Perf Street Sprung Clutch Kit |
| Vehicle fitment | Jeep Wrangler Jk Hd-O/Perf (2012-2018) |
| Type | Clutch Kits - Single |
| 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 V6. The 3.8L Wranglers use a different clutch.
Only if it is a JK. The 2018-up JL uses a different manual transmission and clutch. Send us your VIN if you are not sure which body you have.
ACT rates it at 479 ft-lb at the crank, 21 percent over the factory clutch, with an organic disc built for street and off-road use.
ACT describes the feel as light to moderate pedal effort with smooth engagement and good drivability.
The J013 Heavy Duty pressure plate, the 3001111 sprung organic disc, the PB1006 pilot bearing, the ATCP9 alignment tool and the RB001 release bearing. The flywheel is not included.
The NSG370 six-speed uses a 75W-85 GL-4 manual transmission lube meeting the Mopar MS-9224 spec. Do not use GL-5 gear oil.
