Product Description
Idler Caster
Specifications: 8.000 inch diameter x 4.000 inch width (8.000" x 4.000" | 8 x 4 wheel | 8 x 4 | 203.20mm x 101.60mm)
Specifications
Wheel Dimensions
| Outside Diameter | 8 |
| Inside Diameter | 2.25 |
| Width Side to Side | 4 |
| Bore Depth | 0.63 |
| Bore Outside Diameter | 2.4404 |
Frequently Asked Questions
Q: What is the difference between SU 684-EZ and a standard load wheel?
A: SU 684-EZ is an idler caster wheel assembly, not a load wheel. It is designed to support lateral alignment and steering control rather than primary load support. The 8.000 inch diameter x 4.000 inch width specification is identical to load wheels, but the bearing configuration and material composition are optimized for guidance and reduced drag during directional changes.
Q: Can SU 684-EZ be installed on the front or back of an electric lift truck?
A: SU 684-EZ is typically installed as an idler caster on the non-driven axle (usually the front steer axle) of a three-wheel electric lift truck. Do not install it where primary load wheels are mounted. Confirm your truck design and axle configuration to determine correct positioning. Installing the idler caster in the wrong location will cause steering failure and instability.
Q: Does SU 684-EZ require lubrication after installation?
A: Most SU 684-EZ idler caster assemblies come with sealed or shielded bearings. No manual lubrication is required unless your truck manufacturer specifies greasing intervals in the maintenance schedule. If bearings are open, apply a light NLGI Grade 2 lithium grease every 500 operating hours or annually, whichever comes first.
Q: What symptoms indicate SU 684-EZ needs replacement?
A: Replace SU 684-EZ if you notice: steering difficulty or pulling to one side, squeaking or grinding from the front wheel during turns, excessive wheel play when lifted and spun, flat spots on the tire, or visible crack damage to the wheel body. A worn idler caster reduces turning radius accuracy and increases steering force.
Q: Is SU 684-EZ compatible with both metric and US-standard mounting?
A: SU 684-EZ features dual dimensioning: outside diameter 8 inches or 203.20mm, width 4 inches or 101.60mm. The bore diameter is 2.25 inches inside and 2.4404 inches outside at the mounting flange. Verify your truck frame bore specifications match before ordering to ensure proper fit regardless of whether your truck uses metric or imperial fasteners.
Q: How long does SU 684-EZ typically last in service?
A: Under normal warehouse conditions with regular floor maintenance, SU 684-EZ typically operates for 24 to 48 months before bearing wear or wheel surface degradation requires replacement. Heavy-duty outdoor use on rough concrete or asphalt reduces service life to 12 to 18 months. Avoid operation on debris-filled floors to extend idler caster life.