3.125" White Plastic Trailer Hub Cap Covers - Set of 2
Precision-engineered press-fit bearing protection. Please verify your center bore is 3.125" (Common for 5-Lug) and not 4.25" (Common for 6-Lug) before ordering.
Overview
This set of two 3.125" white plastic trailer hub cap covers is a direct replacement for SKU MD9004W. Designed for a friction-fit installation, these covers provide a clean, finished appearance while sealing your wheel's center bore from road grime and saltwater. Note: This cap is specifically sized for a **3.125" pilot hole** (bore opening), typically found on 5-lug utility and boat trailer wheels.
R&P Service Insight
The "3.125 vs 4.25" confusion is common. Here is the rule of thumb for R&P customers:
- 3.125" (This Product): Fits the center hole of most **5-Lug** trailer wheels.
- 4.25" (Do Not Order): Fits the larger center hole of **6-Lug** trailer wheels.
- Measurement: Always measure the hole in the wheel, not the outer decorative lip of an old cap.
R&P Knowledge Hub
Compatibility: Nominal 3.125" diameter press-fit center bores.
Vehicle / System Fit: Travel trailers, campers, and boat trailers using standard 5-lug axle configurations.
Installation Notes: Measure the center bore of your rim with a caliper. If it measures 4.25", this cap will fall through the opening.
Performance Insight: Unlike chrome-plated steel, this UV-stabilized plastic will never rust, flake, or pit, even in high-salt marine applications.
R&P Repair Insight
Proper fitment is the difference between a clean trailer and a lost cap on the highway. Before you press these in, check your clearances:
- Internal Height: This cap provides **3.25"** of total height. Ensure your grease caps or bearing protectors don't stick out further than 3".
- Bore Prep: Clean the wheel's center bore of any rust or old grease to ensure the plastic ribs "bite" into the rim for a secure fit.
- Installation: Use a rubber mallet or the palm of your hand. Avoid using a metal hammer which can crack the plastic.
Features
Exact 3.125" Barrel
Sized specifically for 5-on-4.5" and other 5-lug trailer wheel center bores.
Complete Pair
Includes two (2) white plastic hub covers to service one full axle.
Zero-Corrosion
Durable white plastic construction is 100% rust-proof and saltwater safe.
High Clearance
3.25" overall height provides room for standard dust caps and bearing protectors.
Specifications
| Specification | Detail |
|---|---|
| Part Number | MD9004W-LOTOF2 |
| Bore Opening Size | 3.125" (3-1/8") |
| Overall Height | 3.25" |
| Material | UV-Resistant White Plastic |
| Mounting Style | Press-In / Friction Fit |
| Application | Trailer Axle Hubs |
Fitment / Application
| Category | Details |
|---|---|
| Primary Fit | 5-Lug Trailer Wheels |
| Common Brands | Travel Trailers, Campers, RVs |
| Measurement Note | Does NOT fit 4.25" bores (6-Lug Wheels) |
| Quantity | Set of 2 Caps |
