ACT 91-03 BMW E36/E37/E46/E39 HD/Perf Street Sprung Clutch Kit

ACT BM17-HDSS is the street-friendly clutch upgrade for the long run of 1990s and early-2000s BMW five-speeds: the E36 318i, 325i, 328i and M3, the E46 323i through 330i, the E34 525i, the E39 528i and 530i, and the Z3. It is the kit to look at when a mildly modified M50, M52, M54 or S52 has started slipping in the upper gears, or when a tired factory clutch and dual-mass flywheel are both due and you would rather convert to a lighter single-mass setup than buy OE parts again.

What this clutch kit does in an E36, E46 or E39

BM17-HDSS pairs ACT's B015 Heavy Duty pressure plate with the 3000819 Performance Street sprung organic disc. ACT rates the combination at 465 ft-lb at the crank, 52 percent over the original clutch, on a 240 mm (9.4 in) disc with a 1.125 in input spline. The full-face organic lining has a high copper content for heat transfer and a steel backing for burst strength, and the sprung hub keeps the soft takeoff these cars are known for. ACT describes the feel as light to moderate pedal effort with smooth engagement, which is the main difference from the 6-pad race kits for the same chassis.

This is a conversion kit. ACT states it must be used with its 601011 Streetlite or 601016 Prolite flywheel, which are sold separately, so the factory flywheel does not go back in. Kit contents are the B015 pressure plate, 3000819 disc, RB172 release bearing, PB1002 pilot bearing and AT83 alignment tool, plus M8-1.25 x 20 mm pressure plate bolts. ACT lists the kit at 14.9 lb.

Symptoms that point to this kit

• Rpm flaring ahead of road speed in third, fourth or fifth at full throttle
• Slip that showed up after an intake, tune, S52 or M54 swap, or forced induction
• Chatter or judder pulling away from a stop
• A dual-mass flywheel that rattles at idle, clunks on and off throttle, or rocks with free play
• A worn release bearing that chirps or growls only with the pedal pressed

How to confirm before you buy

Put the car in fourth around 2,500 rpm and roll into full throttle. If the tach climbs faster than the speedometer, the clutch is slipping. Before blaming the disc, check for a slave cylinder that is not fully returning, a clutch delay valve in the line that has been restricted, and oil on the friction surface from a rear main or input shaft seal, because each of those will glaze a new clutch too. Our slipping diagnosis guide covers separating slip from other driveline faults, and shift flare vs slip explains what the tach movement means. If you are weighing disc types, read our organic vs ceramic disc guide.

Fitment

ACT lists BM17-HDSS for five-speed manual cars only: 1992-1995 325i/is (M50), 1995-1999 328i/is (M52), 1996-1999 318i/is/ti (M44), 1998-1999 323i/is (M52) and the 1996-1999 US M3 (S52); E46 1999-2000 323i/Ci and 328i/Ci (M52) plus 2001-2003 325i/Ci/xi and 330i/Ci/xi (M54); 1991-1995 E34 525i (M50); E39 1997-2000 528i and 2001-2003 525i and 530i; and the 1996-2002 Z3 roadster and coupe including the M Roadster and M Coupe. The E37 in our title refers to the Z3 family, which BMW coded E36/7 and E36/8. It does not cover six-speeds, automatics or the E46 M3, which uses the BM9-HDSS kit instead. Many of these cars have had engine or gearbox swaps, so confirm the engine code and five-speed, or send us the year and VIN before ordering.

The matching flywheel is the ACT 601011 XACT Streetlite: chromoly, 113-tooth ring gear, 15.2 lb, with M12-1.5 x 30 mm bolts included. For track cars that want a harder bite, the BM13-HDG6 race kit uses a 6-pad disc and comes with a Prolite flywheel.

Install notes

• Install the ACT flywheel with new bolts torqued to spec, then mount the B015 plate evenly in a star pattern.
• Fit the supplied PB1002 pilot bearing; a pilot bearing puller gets the old one out of the crank without damage.
• Check the release fork, its pivot pin and the slave cylinder while the gearbox is out; a worn pivot causes noise and poor release.
• On an E46 the driveshaft has to drop, which is the time to replace a cracked guibo with the E46 flex disc and center bearing kit.
• Refill the gearbox with the fluid listed on its case tag, then bleed the clutch hydraulics from the brake reservoir.
• Follow our clutch break-in guide before hard launches.

Will BM17-HDSS fit my 2002 330i?

Yes, if it is a five-speed manual. ACT lists the 2001-2003 330i, 330Ci and 330xi with the M54 five-speed. The six-speed cars and the E46 M3 are not covered.

Can I reuse my factory flywheel?

No. ACT calls BM17-HDSS a conversion kit that must be used with its 601011 Streetlite or 601016 Prolite flywheel. The flywheel is not included in the kit.

How much torque does it hold?

ACT rates it at 465 ft-lb at the crank, 52 percent more than the original clutch. That covers stock and mildly modified M50, M52, M54 and S52 engines with room to spare.

Is the pedal heavier than stock?

ACT describes light to moderate pedal effort with smooth engagement and OE to mild gear rattle, so it stays comfortable for daily driving.

What comes in the box?

The B015 Heavy Duty pressure plate, 3000819 Performance Street sprung disc, RB172 release bearing, PB1002 pilot bearing, AT83 alignment tool and pressure plate bolts.

What else should I replace while the transmission is out?

Check the slave cylinder and release fork pivot, and on an E46 inspect the guibo and driveshaft center bearing since the driveshaft has to come down.

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