SU S674-XL

Frequently Asked Questions

Q: What does the XL designation mean on the SU S674-XL wheel, and how does it differ from standard wheels?
A: The XL designation indicates the SU S674-XL uses an enhanced polyurethane compound and proprietary XL3 steel-polyurethane bonding technology. This means the wheel offers superior durability, longer service life, and better tread adhesion compared to standard Cushothane formulations. The XL3 bonding prevents delamination and hub separation under heavy load cycles. XL wheels typically handle 20 to 40 percent higher load ratings and last proportionally longer than standard alternatives. Use XL wheels in high-cycle warehouses or for heavy-duty applications.

Q: What are the cross-reference part numbers for the SU S674-XL?
A: The SU S674-XL cross-references to L500674, SU674-XL, SU 674-XL-A, L500674ASSY, L500674ASSY1, L500674R, L500674RA1, L500674RA2, and L500674RD4. These part numbers represent the same wheel across different supplier catalogs, truck model generations, or assembly configurations. Always verify your truck documentation or contact your parts supplier to confirm which cross-reference number applies to your specific truck serial number and model year. Using an incorrect cross-reference can result in improper fit or incompatible bore dimensions.

Q: Can I mix SU S674-XL wheels with older standard wheels on the same truck?
A: Do not mix XL and standard wheels on the same truck. Mixing creates uneven tread wear, inconsistent rolling resistance, and handling instability. The truck may pull to the side with older wheels due to different cushioning properties. Always replace all four wheels as a set to maintain uniform performance and safety. If budget is constrained, replace wheels in pairs (front and rear), but do not pair XL wheels with non-XL wheels on the same axle.

Q: What maintenance steps extend the life of the SU S674-XL wheel?
A: Inspect wheels weekly for debris embedded in the tread, remove foreign objects promptly, and clean the wheel face monthly with a damp cloth to prevent dirt accumulation. Check axle bearings every 500 hours and repack with appropriate grease (consult your truck manual for grease type). Rotate wheels every 300 operating hours to distribute wear evenly. Inspect the hub-to-axle interface for corrosion or oxidation, and apply a light rust inhibitor to bare steel areas if needed. Keep the truck stored in a dry location when not in use, as moisture accelerates bearing wear and hub deterioration.

Q: How do I confirm that an SU S674-XL wheel is seated properly on the axle?
A: After installation, spin the wheel by hand; it should rotate freely with no grinding, chattering, or resistance. Visually inspect the gap between the wheel bore and the hub shoulder. There should be zero gap; the bore inner surface must seat flush against the hub. If a gap exists, the wheel has not seated fully. Remove the wheel and check the hub for dirt, corrosion, or damage. Clean the hub with a wire brush if needed, reinstall the wheel, and verify flush seating. If the wheel still does not seat, the bore diameter may be incompatible with your hub. Do not force the wheel onto an incompatible hub.

Q: What symptoms indicate bearing failure in the SU S674-XL assembly?
A: Listen for a grinding, growling, or rumbling sound that increases with truck speed or load. Feel for excessive play in the wheel when you grasp the tire and attempt to move it side to side at the 3 and 9 oclock positions. Watch for smoke or heat emanating from the wheel, which indicates severe bearing friction. The truck may also pull to one side due to uneven rolling resistance from a locked or damaged bearing. If any of these symptoms appear, stop operation immediately and inspect the bearings and axle. Do not operate the truck with failed bearings, as this risks wheel separation and loss of vehicle control.