BK51 Bracket Kit
The BK51 is Pinnacle's patented hidden-hardware bracket kit for steer axle half fender applications on Class 8 trucks. Compatible with the FH55 and FH67 half fenders. Available in two configurations: BK51P with a standard center support and BK51M with a rigid metal center support for high-demand applications. Both include every piece of hardware needed for a complete installation.
Available Configurations
Both variants share the same bracket geometry, anti-blowback design, and limited lifetime warranty. The suffix tells you what to order.
The BK51P uses a standard polymer center support. The right choice for most Class 8 steer axle half fender applications — proven, lightweight, and backed by a limited limited lifetime warranty.
Standard steer axle half fender applications
The BK51M upgrades to a rigid metal center support for applications that demand extra stiffness — high-vibration environments, severe-duty fleets, or anywhere maximum bracket rigidity is required.
High-vibration or severe-duty applications
How to order
Add P to the kit number for the standard center support, or M for the metal center support. Not sure which is right for your application? Call 1-800-735-6510 and we'll sort it out in minutes.
Installation Guide
Watch the step-by-step installation guide for the BK51 bracket kit.
Specifications
What makes this bracket patented
Hidden hardware
No bolts on the fender surface. All fasteners are concealed inside the mount.
Anti-blowback design
Prevents the fender from blowing back into the tire at highway speed.
Correct offset geometry
Engineered to clear spring shackles on the frame — no clearance issues, no cutting.
Frequently Asked Questions
What applications is the BK51 designed for?
The BK51 is designed for steer axle half fender applications on Class 8 trucks. It is compatible with the FH55 and FH67 half fenders.
What is the difference between BK51P and BK51M?
Both kits use the same bracket geometry and include all installation hardware. The difference is the center support: BK51P uses a standard polymer center support, while BK51M upgrades to a rigid metal center support for high-vibration or severe-duty applications.
How many BK51 kits do I need?
You need one kit per two fender pieces installed.
How long does installation take?
Most installs are complete in about an hour per axle. All hardware is included and the bracket mounts without cutting or drilling.
Does this bracket kit come with a warranty?
Yes. All Pinnacle Heavy Duty bracket kits are backed by a limited limited lifetime warranty. If it fails under normal use, we make it right.
Ready to upgrade your rig?
Call us at 1-800-735-6510 — our team will match you to the right fender and bracket in under 5 minutes.