Whether you tow a fishing boat, an RV, or heavy equipment, understanding your trailer’s components is key to safe and efficient hauling. In this guide, we’ll break down essential parts—like small boat trailer hubs, Dexter 5200 axle bearings, and trailer brake backing plates—and share actionable maintenance tips to help you avoid costly breakdowns.
1. Trailer Hubs: The Heart of the Wheel System
A trailer hub assembly secures your wheel to the axle spindle while housing the bearings that enable smooth rotation.
Types of Trailer Hubs:
- Small boat trailer hubs – Corrosion-resistant coatings for marine environments. Ideal for saltwater or freshwater launches.
- Mobile home hub conversion kits – Useful for adapting non-standard hubs to regular trailer wheels.
- Hub & drum assemblies – Combine braking and wheel support in one unit for electric or hydraulic brake setups.
Replacement Tip:
When buying a trailer hub assembly, match:
- Axle capacity (e.g., 3,500 lb, 5,200 lb, 12K axle)
- Bolt pattern (5 on 4.5, 6 on 5.5, 8 on 6.5)
- Bearing set (e.g., L68149/L44649 for 3.5K, 25580/15123 for 5.2–6K, 28682/25520 for 10–12K)
2. Bearings, Seals & Dust Caps: Protecting Your Rolling Components
Bearings reduce friction, but they only perform well if properly protected.
Key Components:
- Trailer wheel bearing caps – Prevent dirt, water, and debris from entering the hub.
- Dust cap covers – An extra layer of protection for bearing caps.
- Trailer dust cap replacement – Should be done if the cap is loose, dented, or leaking grease.
- 5 lug trailer bearings – Common in light-duty setups.
- Dexter 5200 axle bearings – Designed for mid-range load capacity.
Pro Tip:
Always replace grease seals when servicing bearings. A worn seal can leak grease and allow water intrusion, especially after launching a boat.
3. Axle Choices: Matching Load to Strength
If you’re searching where to buy trailer axles near me, start with the load rating.
- 3,500 lb axles – Great for light-duty utility and small boat trailers.
- 5,200–6,000 lb axles – Ideal for enclosed cargo or mid-size equipment haulers.
- Dexter 12K axles – Heavy-duty for industrial and commercial use.
Accessories to Consider:
- 3500 lb trailer axle dust cap – Fits most 3.5K hubs.
- Complete boat trailer axle kits – Include springs, hubs, U-bolts, and hardware for full replacements.
4. Suspension: Leaf Springs & Bushings
Your trailer’s suspension absorbs road shock and prevents frame stress.
Common Parts:
- Straight leaf springs – Basic suspension option for utility trailers.
- 23 inch trailer leaf springs – Used on specific single-axle setups.
- Leaf spring bushings for trailer – Worn bushings cause squeaks, uneven tire wear, and instability.
Maintenance Tip:
Check bushing wear every 12 months. Worn bushings can damage spring eyes and hanger brackets.
5. Braking Systems: Safety First
Trailer brake backing plates house the shoes, magnets, and springs for electric brakes.
- Inspect them for wear every 12,000 miles or annually.
- Replace in pairs (left & right) for even braking performance.
For hydraulic drum brakes, ensure the drum size matches the brake assembly—common sizes are 10", 12", and 12.25".
6. Buying & Maintenance Checklist
Where to Buy:
Search terms like harbor freight trailer wheel bearings, travel trailer jack, or complete axle kits to find the right match online.
Maintenance Routine:
- Every trip: Check tire pressure, lug nut torque, and visible damage.
- Every 6 months: Inspect hubs, dust caps, and springs.
- Every 12 months: Repack bearings, replace seals, inspect bushings, and check brake adjustment.
- After boat launch: Inspect for water ingress in hubs.