A slipping clutch means the table rotates inconsistently, loses speed under load, or fails to engage fully. The W&B clutch system uses alternating steel and Ferodo (friction) discs compressed by springs — and the parts differ by series and table size. The most common cause of clutch problems is wrong parts fitted during a previous rebuild.
How the W&B Clutch Works
The clutch pack consists of alternating steel drive discs and Ferodo friction discs, compressed by spring-loaded plungers. When engaged, the springs push the discs together, creating friction that transmits torque from the main drive to the table. When disengaged, the springs release and the discs separate.
Common Causes of Slipping
- Wrong steel disc for the series: Each series uses a different steel disc (thin, thick/splined, or spur-drive). Fitting the wrong disc means the clutch pack dimensions are incorrect and clamping force is compromised.
- Wrong spring type: 8473-09 (old) and 8473-10 (new) are NOT interchangeable. The wrong spring delivers incorrect clamping force.
- Worn Ferodo discs: Normal wear over time reduces friction material thickness.
- Oil contamination: A hydraulic leak onto the clutch pack destroys friction. Fix the leak, then replace the contaminated discs.
- Missing or broken springs: Each clutch requires 6 spring/plunger sets. A missing spring reduces clamping force by ~17%.
Step 1: Confirm Your Series and Table Size
Before ordering replacement parts, you
must know two things:
- The series — determined by the machine number (left of the dash in the serial). See our Series Identification Guide.
- The table size — this determines whether you have a No.5 or No.6 clutch.
Use our
Clutch Plate Lookup Tool to get the exact part numbers for your combination.
Step 2: Inspect the Existing Parts
When the clutch pack is disassembled:
- Check that the steel discs match the correct part number for your series
- Measure Ferodo disc thickness — compare to a new disc
- Count the springs — should be 6 complete sets
- Check for oil contamination — any oily sheen on the friction surfaces means replacement
- Inspect the spring plungers for wear or corrosion
Step 3: Order Correct Replacement Parts
Use our
Clutch Plate Lookup Tool to identify the exact parts, then request a quote. We source all clutch components direct from W&B UK to original specifications.
Related Parts
- 8211-109 — No.5 Ferodo Disc
- 8211-113 — No.6 Ferodo Disc
- 8473-09 — Spring (Old Type)
- 8473-10 — Spring (New Type)