Product Description
Shimano 10PDA Ball Bearing (BNT4960 & RD11018) | Precision Worm Shaft Support
The Shimano 10PDA Ball Bearing is a high-precision internal component primarily used to support the worm shaft (level wind) and oscillation systems in Shimano’s premium spinning and baitcasting reels. This specialized bearing ensures that the line-lay mechanism operates with minimal friction, preventing the "binding" or "stuttering" often felt in lower-end reels that use plastic bushings in these locations.
Measuring 3 x 6 x 2.5 mm, the 10PDA is the modern global part number that consolidates and replaces several legacy parts, including BNT4960 and RD11018. It is a common "super-tuning" upgrade for reels that originally came with a plastic bushing (BNT4959) on the worm shaft.
Product Specifications
-
Part Name: Ball Bearing / Worm Shaft Bearing
-
Shimano Part Number: 10PDA
-
Cross-Reference Part Numbers: BNT4960, RD11018, RD17707, RD2401, 106CN
-
Dimensions: 3 mm (Inner) x 6 mm (Outer) x 2.5 mm (Thickness)
-
Material: Marine-Grade Stainless Steel (High-precision ABEC rating)
-
Function: Reduces friction in the oscillation and level wind drive train.
Compatible Reel Models
The 10PDA (BNT4960/RD11018) is one of the most widely used "small-format" bearings in the Shimano lineup. It is a direct fit for:
-
Shimano Stella: 18-19 Stella (4000, 4000XG, C5000XG) — specifically for the Worm Shaft.
-
Shimano Stradic: Various FK, FL, and CI4+ series (used in the oscillation slider or worm shaft support).
-
Shimano Tekota: 300, 500, 600 series (Oscillator/Drive support).
-
Shimano Calcutta Conquest: Select models (Level wind support).
-
Shimano Sustain: FI and FJ series.
Technical Tip: Because this bearing is located in the worm shaft assembly, it is highly susceptible to "line spray"—saltwater and grit carried in by the fishing line. If your reel feels "crunchy" only when the line guide is moving, this bearing is likely the cause.
Maintenance & Lubrication Recommendation
The 10PDA bearing operates at high frequency but low torque. To maintain its precision and prevent corrosion, we recommend Deuthlon Lubricants:
-
For Maximum Smoothness: Apply one drop of Deuthlon Power Cast Oil. This ultra-thin lubricant allows the bearing to spin with almost zero resistance, which is critical for the light-pressure movement of the oscillation system.
-
For Saltwater Protection: If you frequently fish in heavy spray, use a tiny amount of Deuthlon Reel Gear Grease on the outside of the bearing shields to create a waterproof barrier, while keeping the internal balls oiled.
-
Cleaning: If the bearing becomes sluggish, soak it in a degreaser, dry it completely, and re-oil. If the "crunch" remains, the stainless races are likely pitted and the bearing must be replaced.
Why Upgrade to the 10PDA?
-
Improved Line Lay: By replacing the factory plastic bushing with a 10PDA bearing, you eliminate the "play" in the worm shaft, resulting in more consistent line stacking on the spool.
-
Extended Gear Life: Reducing friction on the worm shaft lowers the load on the Idle Gears, preventing the plastic teeth from wearing down prematurely.
-
Silent Operation: High-precision stainless balls provide a much quieter retrieve compared to the "whirring" noise of a dry bushing.
