MasterGuard® Hub Installation Kit 506 – 4.25" & 4.75" Gearcase
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MasterGuard® Hub Installation Kit 506 – 4.25" & 4.75" Gearcase
The MasterGuard® 506 is a premium hub installation kit designed for select outboards and sterndrives with 4.25" or 4.75" gearcases. It provides the mechanical interface between your propeller housing and your engine’s driveshaft — and it’s the only hub kit in its class backed by a lifetime warranty for consumer use.
Compatible with Turning Point Express® Mach3, Mach3 OS, Mach4, and Hustler® propeller housings, as well as popular third-party housings including Solas Rubex, Michigan Wheel XHS, and Mercury FloTorq. Always verify your specific engine make, model, and year against the application chart to confirm the correct kit number before ordering.
Key Features
- One-Piece Construction: Marine bronze splines over-molded with glass-filled nylon — eliminating the failure points common in multi-part sleeve-and-spline or pressed-rubber hub designs.
- Shock-Absorbing Cushion: High-tech polymer absorbs gear shock and helps protect the lower unit from impact damage.
- Reusable After a Prop Strike: In most cases the hub can be reused after a strike. If it can’t, it’s covered under warranty.
- Corrosion Resistant: Premium marine bronze splines resist corrosion in both saltwater and freshwater environments.
- Easy Installation: Kit includes hub, thrust washer, and all required hardware with clear step-by-step instructions.
- Lifetime Warranty: Covers engines under 200hp with aluminum or stainless steel props, and engines 200hp+ with aluminum props. Consumer use only.
Specifications
- Kit Number: 506 (11500600)
- Gearcase Fit: 4.25" and 4.75"
- Compatible Prop Housings: Express® Mach3, Mach3 OS, Mach4, Hustler®; also fits Solas Rubex, Michigan Wheel XHS, Mercury FloTorq
- Hub Material: Marine bronze splines with glass-filled nylon over-mold
- Kit Contents: Hub, thrust washer, and installation hardware
Compatible Engine Brands
Evinrude®, Honda®, Johnson®, Mariner®, Mercury®, MerCruiser®, Nissan®, OMC®, Parsun®, Suzuki®, Tohatsu®, Yamaha® — outboards and sterndrives. Always verify your specific engine make, model, and year against the application chart before ordering.
Compatible Propellers (Sold Separately)
- Express® Mach3 13.25x19 – 3-Blade Stainless Steel Propeller
- Express® Mach4 13x19 – 4-Blade Stainless Steel Propeller
- Hustler® 14x11 – 3-Blade Aluminum Propeller
- Hustler® 14x13 – 3-Blade Aluminum Propeller
- Hustler® 14x11 – 4-Blade Aluminum Propeller
- Hustler® 14x13 – 4-Blade Aluminum Propeller
Other MasterGuard® Hub Kits – 500 Series
- MasterGuard® Hub Installation Kit 503 – 4.25" & 4.75" Gearcase
- MasterGuard® Hub Installation Kit 504 – 4.25" & 4.75" Gearcase
- MasterGuard® Hub Installation Kit 505 – 4.25" & 4.75" Gearcase
- MasterGuard® Hub Installation Kit – Model 26
- MasterGuard® Hub Installation Kit – Model 28
- MasterGuard® Hub Installation Kit – Model 11
Parts Desk Insights
Best Use Case: The 506 kit covers the same 4.25" and 4.75" gearcase range as the 503, 504, and 505, but is engine-specific — the correct kit number is determined by the customer’s exact engine make, model, and year. Do not substitute any 500-series kit for another without verifying against the application chart. All four are appropriate for higher-horsepower outboards and sterndrives (typically 75hp and above) running Express® or Hustler® propeller housings on larger gearcases.
Hub Kit vs. Propeller: This kit is the hub only — the propeller housing is sold separately. Customers replacing a damaged prop only need to purchase a new housing, not a new hub, which can significantly reduce replacement cost.
Cross-Brand Compatibility: This hub also fits Solas Rubex, Michigan Wheel XHS, and Mercury FloTorq housings — useful when a customer already has a non-Turning Point prop and wants to upgrade to the MasterGuard® hub system for better lower-unit protection.
Warranty Note: The lifetime warranty applies to consumer use only and excludes extreme commercial applications. Direct customers to the manufacturer’s warranty page for full terms.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.