ACT 91-95 BMW 525i 96-99 318i HD/Race Sprung 6 Pad Clutch Kit

If your E36 track car, turbo M50 swap or E34 525i five-speed is slipping in third and fourth under full throttle, the factory-style organic disc has run out of clamp load. ACT part number BM13-HDG6 is a Heavy Duty pressure plate paired with a 6-pad sprung ceramic race disc and an ACT Prolite flywheel. ACT lists it for the 1991-1995 525i, the 1996-1999 318i and a long run of other 1990s and early-2000s BMW six-cylinder and four-cylinder five-speeds. ACT rates it at 596 ft-lb at the crank, 94 percent more than the original clutch.

What the HD race 6-pad clutch does in an E36 or E34

These BMWs left the factory with a full-face organic disc that is smooth but built with little margin over stock torque, and many of them use a dual-mass flywheel. BM13-HDG6 is a conversion: whatever flywheel the car has comes off and ACT's single-mass Prolite flywheel goes on and puts a 240 mm (9.4 in) ceramic disc against it. Six separate pads mean less contact area than a full-face disc, so each pad sees more pressure and the clutch grips harder for the same pedal. The sprung hub keeps some torsional damping, which matters once the factory flywheel's damping is gone. ACT's Heavy Duty diaphragm raises clamp load while keeping pedal effort light to moderate. The trade-off ACT is upfront about: engagement is aggressive, shifts are faster, and you can get mild gear rattle at idle. ACT recommends it for high-horsepower street or race use, not as a stock replacement.

Symptoms that point to this kit

• Clutch slipping under load in the higher gears after a turbo, supercharger or S52 swap
• Chatter on takeoff from a glazed disc or a heat-spotted flywheel
• A worn dual-mass flywheel that rattles, clunks on tip-in or shows excessive free play
• Repeat disc failures from launches or track sessions
• Burnt smell after a hard lap or a hill start with a trailer

How to confirm the clutch is the problem

Do a rolling test in fourth gear from low rpm at full throttle. If the tach climbs faster than road speed, the clutch is slipping. Before buying, rule out a slave cylinder that is holding the fork partly applied, a clutch delay valve that has been restricted, and oil on the disc from a rear main or input seal leak, because any of them will ruin a new clutch. Our slipping diagnosis guide walks through separating clutch slip from other driveline faults, and the shift flare vs slip guide helps you read what the tach is telling you. If you are still choosing a disc, our organic vs ceramic disc guide covers the street manners of a puck disc.

Fitment

Our listing title calls out the 1991-1995 525i (E34, M50) and the 1996-1999 318i (E36, which switched from the M42 to the M44 four-cylinder for 1996). ACT's own application chart for BM13-HDG6 is wider and includes the 1992-1995 325i and 325is, 1995-1999 328i and 328is, 1998-1999 323i and 323is, 1996-1999 US M3 (S52), 1999-2003 E46 323i, 325i, 328i and 330i five-speeds, 1997-2003 E39 528i, 525i and 530i five-speeds, and 1996-2002 Z3 including the M Roadster and M Coupe. ACT lists five-speed applications only; it does not cover six-speed cars, automatics or the E46 M3. Because many of these cars have had engine or transmission swaps, confirm your engine code and five-speed gearbox, or send us the year and the last 7 of the VIN before ordering. A street-focused option for the same chassis is the ACT HD Perf Street sprung kit BM17-HDSS. More clutch kits are in our rebuild kits department.

Install notes

• This kit only works with the included ACT Prolite flywheel. The original flywheel, dual-mass or not, does not go back in.
• ACT includes M12-1.5 x 30 mm flywheel bolts and M8-1.25 x 20 mm pressure plate bolts. Use them, torque to spec, and tighten the pressure plate evenly in a star pattern.
• Replace the pilot bearing and inspect the release fork, pivot and slave cylinder while the transmission is out. A universal clutch alignment kit helps center the disc if you do not have a BMW tool.
• On an E46 the driveshaft has to come off for the job, which is a good time to replace a cracked guibo with the E46 flex disc and center bearing kit.
• Refill the gearbox with the fluid called for on its case tag, since BMW used different fluids across these five-speeds, then bleed the clutch hydraulics from the shared brake reservoir.
• Break the clutch in gently on the street before track use; see our clutch break-in guide.

Does BM13-HDG6 fit my 1998 328i?

Yes, if it is a five-speed manual. ACT lists the 1995-1999 328i and 328is (M52) along with most 1991-2003 E34, E36, E39, E46 and Z3 five-speed cars. It does not list six-speeds, automatics or the E46 M3.

Can I keep my factory flywheel?

No. This is a conversion kit and must be used with the ACT Prolite single-mass flywheel that comes in the box, along with new flywheel and pressure plate bolts.

How much torque will it hold?

ACT rates BM13-HDG6 at 596 ft-lb measured at the crank, 94 percent over the original clutch. That is far beyond a stock M44, M50, M52 or S52, so it suits forced induction and race cars.

Is it okay for daily driving?

It can be driven on the street, but the 6-pad ceramic disc engages aggressively and the single-mass flywheel can bring mild gear rattle at idle. For a mostly street car, a full-face street disc is the smoother choice.

What else should I replace with it?

Replace the pilot bearing, check the slave cylinder and release fork pivot, and on an E46 inspect the guibo and center bearing while the driveshaft is out.

What fluid goes back in the transmission?

Use the fluid shown on the tag on your gearbox case. BMW five-speeds of this era did not all use the same fluid, so check before filling.

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