RS Series Rock Sliders on a GMC Sierra 2500HD Double Cab
By Armordillo® | Premium Truck & SUV Accessories – Armordillo4x4 | Published: 2026-11-02
Category: How-to Guides
Mount Armordillo RS Series side steps on your 2020-2026 GMC Sierra 2500HD or 3500HD Double Cab with a clean, torque-checked process and fewer fitment surprises.
Quick answer
Mount the Armordillo RS Series side steps to the factory rocker locations on your 2020-2026 GMC Sierra 2500HD or 3500HD Double Cab, tighten the brackets in stages, and finish with a torque check after the first week of driving.
Why the Double Cab and model year decide the fit
The RS Series listing covers 2020-2026 GMC Sierra 2500HD and 3500HD Double Cab trucks. Crew Cab and Regular Cab body styles have different rocker lengths, so confirm your cab style on the door jamb label or registration before ordering. The same listing does not publish bracket dimensions or a step-by-step template, so treat the factory mounting points on your own truck as the reference during the install.
Because the catalog does not list a no-drill guarantee or a specific torque value, plan to inspect the rocker for existing threaded holes and to follow the hardware instructions included with your set. If your truck has aftermarket rocker guards or mudflap brackets occupying those holes, resolve that interference before you start tightening anything.
Texture black finish: what to expect on a heavy truck
The texture black coating hides road grit and scuffs better than a polished finish, which suits a 2500HD or 3500HD that sees gravel roads, jobsites, or winter salt. The trade-off is that textured coatings can trap fine dust in the grain, so rinse and scrub the step surface rather than relying on a quick spray. Avoid abrasive pads on the coating; a soft brush and mild soap keep the texture intact.
Step-by-step RS Series mounting process
- Confirm cab style and model year: Check the door jamb label or registration to verify your truck is a 2020-2026 GMC Sierra 2500HD or 3500HD Double Cab. Common mistake: ordering for a Crew Cab because the listing photo looks similar; the rocker length differs and the brackets will not line up. Snap a photo of the door jamb label before you order so the cab style is documented.
- Lay out hardware and read the included instructions: Sort bolts, brackets, and any spacers by location, and read the hardware sheet that ships with the set. The catalog does not publish a torque spec, so use the value in the included instructions. Common mistake: guessing a torque figure from a different brand's running board. If the hardware sheet is missing, contact the seller before installing rather than improvising a torque value.
- Clean and inspect the factory mounting points: Wire-brush dirt and undercoating from the rocker threads and check for rust or damaged threads. Common mistake: threading bolts into dirty holes, which cross-threads and weakens the joint. Chase any rough threads with a tap before mounting the bracket.
- Loosely hang the brackets and step: Start all bracket bolts by hand, then set the RS Series step on the brackets and start its fasteners finger-tight. Common mistake: fully tightening one bracket before the others are started, which pulls the step out of alignment. Leave every fastener loose until the step sits level along the rocker.
- Align the step and check door clearance: Adjust the step fore and aft so it sits centered on the Double Cab doors and check that the front and rear doors open without contact. Common mistake: setting the step too far forward, where the front door edge catches it. Open and close both doors fully before final tightening.
- Torque in stages, then re-check after a week: Tighten the bracket and step fasteners in a cross pattern to the value in the included instructions, then drive for a week and re-torque. Common mistake: skipping the re-check, which lets new joints settle loose. Put a re-torque reminder on your calendar for one week after the install.
Product facts
- ARMORDILLO® RS SERIES 2020-2026 GMC Sierra 2500HD 3500HD Double Cab Side Step Rock Slider - Texture Black: ARMORDILLO® RS Series side steps for the 2020-2026 GMC Sierra 2500HD 3500HD Double Cab, finished in texture black. The listed cab and year range matches the Double Cab HD trucks this guide covers, so you can check fitment against your own door tag before ordering.
ARMORDILLO® RS SERIES 2020-2026 GMC Sierra 2500HD 3500HD Double Cab Side Step Rock Slider - Texture Black
