Product Description
Poly Press-On Assy
Specifications: 8.500 inch diameter x 4.000 inch width (8.500" x 4.000" | 8.5 x 4 wheel | 8-1/2 x 4 | 215.90mm x 101.60mm)
Specifications
Wheel Specifications
| Outside Diameter (in) | 8.500 |
| Width (in) | 4.000 |
| Outside Diameter (mm) | 215.90 |
| Width (mm) | 101.60 |
| Drive Tire Profile | Smooth Flat |
| Material | Polyurethane |
Frequently Asked Questions
Q: How does the SU 8.5X4X4-SF-P-A assembly differ from the press-on SF-P wheel?
A: The SU 8.5X4X4-SF-P-A is a complete assembly that includes the polyurethane tire, hub, and bearing in one unit. You mount it directly to your axle shaft. The press-on SF-P wheel is just the tire and slides onto your existing hub. The -A assembly is the choice when you need a full wheel replacement. The -P press-on is better when your hub is still good and you only need to replace the worn tire.
Q: Is the SF-P-A assembly compatible with all truck axles?
A: No. Axle shaft sizes vary. The SF-P-A assembly is designed for standard 0.625 inch or 0.750 inch diameter axle shafts commonly found on 4000 to 8000 lb electric lift trucks. Verify your truck manual for axle shaft diameter before ordering. Do not attempt to force an assembly onto a shaft that does not match. An incorrect fit will not spin freely and can damage the bearing immediately. Contact the part number manufacturer with your truck model for exact compatibility.
Q: What performance advantages does polyurethane offer in the SF-P-A assembly?
A: Polyurethane is 30 to 40 percent harder than rubber, resists abrasion and oil degradation, and lasts longer on concrete and smooth floors. It does not chunk or tear as easily as rubber. Polyurethane maintains consistent grip even when worn. The trade-off is increased noise and less traction on wet or slippery surfaces. Polyurethane is the right choice for high-use warehouses and outdoor operations where durability matters most.
Q: How do I install the SF-P-A assembly onto my truck?
A: Support the truck or lift it on a jack so the wheel is off the ground. Remove the retaining bolt or clip holding the old wheel to the axle. Slide the old wheel off the shaft. Align the new SF-P-A assembly bore with the axle shaft. Slide the assembly onto the shaft until the hub flange seats against the axle shoulder. Install the retaining bolt finger-tight first, then use a wrench to torque it to 45 to 55 foot-pounds. Do not over-tighten. Spin the wheel freely to confirm it does not bind. Repeat for all wheels and test the truck.
Q: What maintenance is needed for a polyurethane assembly to maximize lifespan?
A: Keep the wheel and hub clean of debris weekly. Check that the retaining bolt remains tight monthly because vibration can cause it to loosen. If the wheel squeaks, the bearing may need a small amount of grease. Do not over-grease because excess grease attracts dirt and can damage seals. Inspect the tire surface for cracks quarterly. Replace the assembly if cracks appear because polyurethane degradation accelerates once cracking begins. A well-maintained SF-P-A assembly typically lasts 4 to 6 years.
Q: What symptoms mean the SF-P-A assembly is failing and needs replacement?
A: Flat spots on the tire indicate wear and loss of drive grip. Chunks missing or cracks in the polyurethane mean immediate replacement is needed. If the wheel wobbles or pulls to one side, the hub or bearing may be bent or seized. Rough spinning or grinding noise indicates bearing failure. If the wheel does not spin freely by hand after removal, the bearing is shot. Any combination of these symptoms means the assembly cannot be repaired and must be replaced as a unit.