SU S9159-A

Frequently Asked Questions

Q: What is the difference between the SU S9159 and SU S9159-A wheel?
A: Both wheels are 4.00 inch diameter by 2.00 inch width polyurethane load wheels for electric lift trucks. The primary difference is hub material: the SU S9159 uses a machined carbon steel hub with sealed bearings, while the SU S9159-A uses a cast iron core with machined finishing. Cast iron provides corrosion resistance in damp environments and potentially longer lifespan in wet conditions. The SU S9159-A tread is high-rebound industrial-grade polyurethane, offering better shock absorption than some standard compounds. Choose the A-version for wet or harsh chemical environments.

Q: What does high-rebound polyurethane mean for the SU S9159-A?
A: High-rebound polyurethane means the tread returns quickly to its original shape after compression under load. This property reduces flat-spotting and improves ride quality, especially on rough or uneven floors. High-rebound compounds are also more resilient to impact damage from dropped objects or floor obstacles. However, high-rebound formulas may wear slightly faster than harder, less-resilient compounds in high-cycle operations. The SU S9159-A balances durability with shock absorption, making it ideal for facilities with frequent impact loads or uneven surfaces.

Q: Can I interchange the SU S9159-A with a standard SU S9159 on my electric pallet jack?
A: Yes, both wheels are dimensionally interchangeable at 4 x 2 inches with standard drop-in axle mounting. Upgrade to the SU S9159-A if your facility has wet conditions, chemical exposure, or rough uneven floors. The cast iron core and high-rebound compound provide better performance in these environments. Replace all four wheels with the same specification for consistent traction and steering response. Mixing wheel types may cause steering imbalance and uneven load distribution.

Q: How do I install the SU S9159-A wheel on my electric lift truck?
A: The SU S9159-A is a direct replacement using drop-in axle mounting. Remove the cotter pin or retaining clip from the axle. Slide the old wheel off. Position the new wheel and slide it fully onto the axle shaft until the bore seats completely against the axle stop. Secure with the original cotter pin or retaining hardware. Spin the wheel by hand to verify smooth rotation. The wheel should not contact the truck frame or steering components. Do not over-tighten bolts; hand-snug plus a quarter-turn is typically sufficient.

Q: What is the typical lifespan of the SU S9159-A in wet environments?
A: In wet or damp environments, expect 24 to 30 months of service life. The cast iron core resists rust and corrosion compared to steel, extending longevity in chemical or high-moisture facilities. The high-rebound polyurethane tread maintains elasticity longer in cold or wet conditions. Inspect every 3 months for tread degradation, as moisture accelerates polyurethane aging. Ensure proper drainage in storage areas to prevent water sitting on the wheel core. Clean tread of accumulated water or residue to prevent accelerated wear.

Q: How do I diagnose if the SU S9159-A wheel is failing?
A: Watch for soft or squishy feeling tread, which indicates polyurethane degradation or separation from the core. Audible squeaking during rotation may indicate bearing wear or core damage. Flat spots or visible chunking on the tread surface require immediate replacement. Uneven wear patterns (one side worn faster than the other) indicate wheel misalignment or bent axles. If the truck pulls to one side, that wheel may be damaged or failing. Loss of the non-marking property (black residue on floors) indicates tread compound breakdown. Replace immediately when any of these symptoms appear.