TDZ MOTO derby cover bolt & O-ring kit — 6 stainless bolts + 20 #11105 O-rings, fits Big Twin/Sportster/M8 Touring

TDZ MOTO's bolt and O-ring kit supplies six precision Allen button-head bolts plus washers and 20 #11105 O-rings designed for many Harley derby covers and related engine side covers.

This hardware pack is intended for a wide range of Harley-Davidson models and offers a straightforward replacement or upgrade for worn or missing derby cover fasteners. The kit contains machine screws, small flat washers, internal star lock washers, and a generous supply of #11105 O-rings so you can refresh the sealing and fastening components at once. Note: this kit does not fit Harley M8 Softail models from 2018–2026.

Which Harley models will these bolts and O-rings fit?

The kit is compatible with many common Harley models, including Big Twin bikes, Sportsters, and most M8 Touring and Trike models within the specified year ranges. Always check the bolt thread size and your vehicle’s derby cover hole pattern (5- or 6-hole) before ordering. If your bike is a Harley M8 Softail from 2018–2026, this kit is not suitable.

• Big Twin: 1999–2016 (most vehicles)
• Sportster XL & XR: 2004–2024 (most vehicles)
• M8 Touring & Trikes: 2017–2026 (most vehicles)
• Not compatible with Harley M8 Softail models 2018–2026

What hardware and quantities are included in the kit?

This pack gives you everything needed to replace the visible derby cover fasteners and their small sealing components. You get six Allen socket button-head machine screws with matching small flat and internal star lock washers, plus twenty #11105 O-rings so you can replace O-rings on multiple covers or keep spares on hand.

• Six Allen socket button-head machine screws (bolts)
• Six small outside-diameter flat washers
• Six small outside-diameter internal star lock washers
• Twenty #11105 O-rings for seals and spares

What are the bolts made of, and how do they perform?

The kit’s fasteners are manufactured from corrosion-resistant stainless steel for long-term durability and rust resistance. Their machine-thread design and 1/4"-20 fit make installation quick and repeatable; the included lock washers improve retention under vibration. These parts are intended as hardware replacements, not as a cosmetic-only trim piece.

• Material: stainless steel for strength and rust resistance
• Thread: 1/4"-20 sizing for common derby cover holes
• Lock washers included to reduce loosening from vibration
• Button-head Allen design for clean, low-profile appearance

How easy is this kit to install and maintain?

Installation is straightforward for anyone comfortable with basic hand tools and a torque wrench. Remove the old bolts and O-rings, clean mating surfaces, install new O-rings and washers, then torque the Allen bolts to the manufacturer’s recommended spec. Keep extra O-rings from the pack as spares for future maintenance or other small sealing tasks on your bike.

• Simple hand-tool installation—Allen hex key and torque wrench recommended
• Clean mating surfaces before fitting new O-rings for reliable sealing
• Save extra O-rings for future replacements or projects

Who is this for: This TDZ MOTO kit is meant for Harley owners, mechanics, and restorers who need reliable replacement derby cover hardware and spare O-rings. It's particularly useful for riders maintaining Big Twin (1999–2016), Sportster (2004–2024), or most M8 Touring/Trike models (2017–2026) who want corrosion-resistant fasteners and a ready supply of seals. If your bike is an M8 Softail from 2018–2026, choose a different kit verified for that frame.