Installation instructions for the South Bend Duramax dual disc (DD) clutch kit. The guide provides flywheel-to-crank torque of 140–150 ft-lbs and pressure-plate torque of 45 ft-lbs, and walks through disc alignment and assembly for strong, smooth engagement.
Download the Original PDF Manual
IMPORTANT: Please read these instructions carefully before you begin. Failure to follow them will negatively affect the performance of your clutch and may void your warranty. This unit may appear different than your old part due to design differences between manufacturers — it will function properly in your vehicle.
Torque Specifications
- Flywheel to crank: 140–150 ft-lbs
- Pressure plate to flywheel: 45 ft-lbs
Installation Instructions
- Unbolt the existing pressure plate from the flywheel in a star pattern, using quarter turns.
- Check the discs on the input shaft for free movement before installation.
- Bolt the flywheel to the crank using the provided specs (140–150 ft-lbs).
- Line up the paint marks on the pressure plate, center plate, and flywheel.
- Install the discs according to the sticker (located on the disc) for correct hub direction.
- Install the pressure plate bolts in a crossing (star) pattern, one quarter turn at a time.
WARNING: Do not use air-powered (impact) tools for this step.
- Refer to the Important Information Form (included with the kit) for additional installation information.
NOTE: Some prying may be required to level the fingers of the clutch. Use a small pry bar positioned between the cover and the diaphragm spring to force any high fingers down to a uniform position.
Best Practices
Never
- Force the input shaft into the disc hub — it will bend the disc or scar the splines.
- Allow the weight of the transmission to hang on the disc.
- Touch the friction surface of the disc with greasy hands.
- Use an impact wrench to tighten the pressure plate mounting bolts.
- Install a new disc without replacing the pressure plate and release bearing.
Always
- Use the proper alignment tool.
- Check the fit of the disc hub splines to the input shaft before installation.
- Resurface or replace the flywheel.
- Tighten the pressure plate bolts in a “star” or criss-cross pattern, one turn at a time.
Flywheel Resurfacing
- Flywheels should not be lathe cut.
- The OEM taper on the flywheel runs approximately 0.002–0.003″ from outside to inside. This does not need to be matched — a flat surface is preferred with this clutch.
- Resurface flywheels with a grinder specifically built for grinding flywheels. Do not aim for a rough finish — the smoother, the better.
- Make sure the pressure plate bolt holes are thoroughly cleaned after resurfacing. Running a thread chaser or tap will ensure the threads are clear of all debris.
Break-In Procedure
ATTENTION: High-performance clutches require a break-in period. Approximately 200 miles of normal city driving (stop-and-go) should properly break in your clutch. If slipping occurs, resume normal driving for another 50 miles.
Disc Noise — Important Notice (Read Before Installation)
This South Bend Clutch disc uses a newly designed assembly containing 6 neoprene dampeners and 2 coil springs. Some noise may be associated with this design.
Due to an industry-wide problem with the short life of torsional springs in clutch discs, this area has been upgraded. Reasons for premature spring failure include:
- Power enhancements to the engine
- Overloading or continuous heavy towing
- Excessive idling of the engine
- Habitually accelerating in the wrong gear
- Poorly tuned engines
- Worn transmission parts
- Misalignment of engine and transmission
- Pilot bearing failure
- Continuous down-shifting
Because many of these conditions often exist in combination, a stronger disc is necessary to increase the life of the clutch. By strengthening the springs, the disc has been made more rigid, which can allow some low-end engine vibration to transfer to the transmission. This may create a noise known as gear rollover (sometimes called idle clatter), most noticeable when the truck is in neutral at idle RPM, and occasionally when accelerating at too low an RPM.
The amount of noise varies from truck to truck and may depend on how the truck has been modified and how well the engine runs. This noise does not harm the truck in any way. Although it may be a nuisance, it is the only way to prolong the life of high-torque clutch systems in heavy-duty applications. The original (softer-spring) design is available upon request.
Support
- For assistance: call ECD Diesel at 717-861-7525.
- For technical assistance: call South Bend Clutch directly at 800-988-4345.