Where to Find Replacement Parts for Twin Disc SP11P301 Clutches in Chippers

[MikePhua]

Twin Disc Company and SP Series Overview
Twin Disc, founded in 1918 in Racine, Wisconsin, is a global manufacturer of power transmission equipment for marine, off-highway, and industrial applications. Their product line includes power take-offs (PTOs), clutches, torque converters, and gearboxes. The SP series, including the SP11P301 model, is commonly used in wood chippers, grinders, and other forestry equipment. These clutches are designed to engage and disengage high-torque loads, allowing the engine to start under no-load conditions and then transmit full power to the driven equipment.
The SP11P301 is a mechanical PTO clutch with a spring-loaded engagement system and friction disc pack. It is often found in Bandit 250 chippers and similar machines. Over time, these clutches wear out due to heat, vibration, and high torque cycling, requiring rebuilds or replacement parts.
Terminology Notes

• PTO (Power Take-Off): A mechanical device that transfers power from an engine to auxiliary equipment.
  
• Friction Disc: A replaceable component that transmits torque through friction when clamped between pressure plates.
  
• Throwout Bearing: A bearing that disengages the clutch when the operator pulls the lever or pedal.
  
• Spline Hub: The internal gear that connects the clutch to the driven shaft.
  

Common Failure Points and Symptoms
Operators often report that the clutch becomes “trashed,” meaning it no longer engages properly or slips under load. Common causes include:

• Worn Friction Discs: Loss of material reduces torque capacity.
  
• Damaged Pressure Plate: Warping or cracking from overheating.
  
• Failed Bearings: Noisy operation or difficulty disengaging.
  
• Broken Springs or Levers: Prevent full engagement or cause uneven pressure.
  

In forestry applications, clutches are exposed to dust, wood chips, and high shock loads, accelerating wear. Regular inspection and maintenance are essential to prevent catastrophic failure.
Aftermarket and OEM Parts Availability
Several suppliers stock replacement parts and complete units for the SP11P301 and similar models:

• K&L Clutch and Transmission: Offers same-day shipping on Twin Disc, Rockford, WPT, and NACD clutches. They stock SP211P301 and WTD-11-230 equivalents commonly used in Bandit and Morbark chippers.
  
• Northern Engine (Duluth, MN): Known for reliable access to Twin Disc parts, especially for forestry and industrial applications.
  
• Foley Engines (Massachusetts): Supplies Twin Disc, Rockford, and Autoclutch components. They also offer technical support for identifying parts by serial number.
  

When sourcing parts, it’s important to provide the full model number and serial number stamped on the clutch housing. This ensures compatibility, especially for older or discontinued models.
Field Anecdote and Practical Insight
In upstate New York, a chipper operator discovered his SP11P301 clutch had failed mid-season. With no local dealer support, he contacted a regional supplier who had a replacement in stock. The new unit arrived within 48 hours, and the machine was back in service by the weekend. He emphasized the importance of keeping a spare throwout bearing and friction disc set on hand during peak season.
In Minnesota, a retired construction superintendent recalled that his team once scrapped a brand-new PTO clutch that sat unused in a crate for 40 years. The company had lost track of its purpose, and no one could identify the machine it belonged to. He now advises labeling and logging all spare parts with equipment cross-references.
Recommendations for Owners and Mechanics

• Keep a Spare Parts Kit: Include friction discs, springs, and bearings for quick field repairs.
  
• Inspect Clutch Every 250 Hours: Look for heat discoloration, wear, and oil contamination.
  
• Use OEM or Certified Aftermarket Parts: Avoid generic substitutes that may not match torque ratings.
  
• Clean and Lubricate Linkages: Prevent binding and uneven engagement.
  
• Document Serial Numbers and Part Sources: Simplifies future ordering and warranty claims.
  

Final Thoughts
The Twin Disc SP11P301 clutch is a critical component in many wood chippers and industrial machines. While robust, it requires periodic maintenance and timely replacement of wear parts. With multiple suppliers offering fast shipping and technical support, downtime can be minimized. Operators who proactively stock parts and maintain clear records will avoid costly delays and keep their equipment running through the toughest seasons.