Product Description
SOUTH BEND 13125-OK SINGLE DISC CLUTCH — 400HP — 1988–2004 DODGE RAM 5.9L CUMMINS
Proven street/tow drivability with real holding power. The South Bend 13125-OK is a 13" organic single-disc conversion clutch that upgrades the early 12.25" setup to a stronger 13" system with a matching flywheel. It’s ideal for daily drivers and tow rigs targeting ~400 HP / ~800 lb-ft with smooth engagement and excellent modulation.
- Capacity: ~400 HP / ~800 lb-ft (vehicle dependent)
- Friction: Full organic single disc for smooth, quiet operation
- Flywheel: Included — 13" conversion (replaces 12.25")
- Use case: Daily driving, towing, light performance
FITMENT
- Engine: 5.9L Cummins (12V & 24V)
- Model Years: 1988–2004 Dodge Ram 2500/3500
- Transmissions: Getrag 5-speed (1988–1993), NV4500 5-speed (1994–2004), NV5600 Non-HO 6-speed (approximately 1999–2000.5)
- Input Shaft: 1.25" (stock Getrag/NV4500 and early NV5600 Non-HO). Not for 1-3/8" (1.375") upgrades.
WHAT’S INCLUDED
- Pressure plate (diaphragm style)
- 13" organic clutch disc
- Matched 13" flywheel (conversion)
- Pilot bearing, release bearing, alignment tool, hardware
CROSS-REFERENCE / ALTERNATIVES
- South Bend 13125-OK-HD (425HP) — heavier clamp organic
- South Bend 13125-OFEK (475HP) — organic/feramic upgrade
- South Bend 13125-OR (400HP) — organic repair kit alternative
- ARP 147-2802 Flywheel Bolt Kit — recommended hardware
INSTALL NOTES
- Confirm input shaft diameter before ordering (this kit is for 1.25").
- Break-in per South Bend guidelines for best life/engagement.
- Consider fresh/HD hydraulics if your OE system is aged or if pedal effort/release is inconsistent.
FAQ
Does this convert my truck to a 13" clutch?Yes. The 13125-OK includes a matched flywheel to convert early 12.25" applications to a 13" clutch system for improved capacity and heat management.
Which transmissions does it fit?
Getrag 5-speed (’88–’93), NV4500 5-speed (’94–’04), and NV5600 Non-HO (roughly ’99–’00.5). It is not intended for later NV5600 HO trucks.
What input shaft size is required?
1.25" stock input. If you have or plan a 1-3/8" input upgrade, select an appropriate 1.375" clutch instead.
Is pedal feel similar to stock?
Pedal effort is close to stock with smooth, progressive engagement thanks to the organic facing and diaphragm pressure plate.
What hardware do you recommend?
Use new flywheel bolts during installation. We recommend the ARP 147-2802 kit.
