Product Description
5 X 3.75 Poly Load Wheel, Assy
Frequently Asked Questions
Q: What does the -A designation mean on SU S377-A?
A: The -A suffix indicates that SU S377-A is a complete wheel assembly (Assy) that includes the wheel, hub, and bearings pre-assembled on a common axle. SU S377 is the wheel core only. If you need a plug-and-play replacement, order SU S377-A. If you only need the wheel and your existing bearings and hub are good, order SU S377 wheel only.
Q: Can I install SU S377-A as a direct replacement for a failed wheel and bearing set?
A: Yes, but only if the axle bore diameter matches. SU S377-A assembly arrives pre-assembled and ready to slide onto an existing axle. Remove the failed wheel, bearing, and axle if necessary, then install the SU S377-A assembly. If the axle is bent, damaged, or the bore diameter does not match, you must replace the axle first. Do not force-fit an assembly onto a mismatched axle or it will damage bearings immediately.
Q: What bearing type is included with SU S377-A and how do I maintain it?
A: SU S377-A typically includes sealed ball bearings or open ball bearings depending on the assembly version. Sealed bearings are maintenance-free for the life of the wheel. Open bearings require annual re-greasing with general-purpose wheel bearing grease. Spin the wheel by hand monthly to check for smooth operation. Do not over-grease open bearings, as excess grease creates drag and heat buildup. Use a hand pump grease gun only.
Q: How do I know if the SU S377-A assembly is properly seated on my axle?
A: The hub shoulder must fully contact the axle shoulder with no gaps. After installing SU S377-A on the axle: (1) hand-tighten the axle nut, (2) rotate the wheel and listen for noise or binding, (3) try to move the wheel side-to-side (should be zero play), (4) torque the axle nut to 25-35 ft-lbs, (5) re-check for play and smooth spin. If the wheel rocks side-to-side or grinds, remove and inspect the bore diameter and axle for damage.
Q: Is SU S377-A available with different bearing grades or sealing options?
A: Assembly configurations may vary. Contact your supplier to confirm if SU S377-A is available with sealed, shielded, or open bearings. For wet environments or frequent cleaning, specify sealed bearings. For dry indoor use, open bearings are acceptable. Some suppliers offer -S (sealed) or -O (open) variants. Always confirm the bearing type in your purchase order to ensure compatibility with your maintenance plan.
Q: What is the warranty or expected lifespan of an SU S377-A assembly?
A: SU S377-A assemblies are typically warranted for manufacturing defects for 12-24 months depending on the supplier. Actual lifespan under normal duty is 5-8 years for the wheel and 7-10 years for the bearings. Heavy-duty continuous use or overloading reduces lifespan by 30-50 percent. Keep purchase documentation and service records to validate warranty claims. Damage from misinstallation or overload is not covered by warranty.