How to Install a Ram ProMaster Full Interior Trim Kit with Master RAIL | Complete Installation Guide

Last updated: September 29, 2026

Overview

Install a ProMaster full interior trim kit with master rail system in 3–4 hours using self-tapping screws and provided mounting hardware. The kit covers B-pillars, C-pillars, D-pillars, and includes a master rail system for easier wall and ceiling panel terminations. By covering all complex metal pillar surfaces, your ProMaster interior gets a seamless, finished appearance.

Before You Start

  • Vehicle: Ram ProMaster

  • Kit: ProMaster Full Interior Trim Kit with Master Rail

  • Mounting location: B-pillars, C-pillars, D-pillars, and the wall/ceiling Master Rail running B-to-D (driver) and C-to-D (passenger)

  • Estimated installation time: ~3-4 hours

Tools & Materials

  • #2 Phillips screwdriver, drill

  • 23/64" drill bit

  • Rivnut gun/tool

  • 5/32" Allen wrench

  • Rivet gun

  • Primer (rivnut/adhesion primer)

  • An extra set of hands (recommended for setting the Master Rail)

  • x10 Truss screws, x8 M5 bolts, x8 M5 rivnuts, x2 1/4-20 bolts, x2 1/4-20 rivnuts, Loctite (included with the kit)

Installation Instructions

  1. 1. Install the DS B-pillar. Remove the factory foam. Set the B-pillar cover in place and let the wall flange index to the sheet metal. Push the trim forward and fasten the flange to the sheet metal with 1-2 self-tapping screws.

    2. Position the PS B-pillar. Remove the factory foam. Set the B-pillar cover in place with the bottom edge resting against the weather stripping over the door. Clamp it in place for now. You'll secure it in step 7.

    3. Prep for the D-overhead. Hold the trim piece in place and mark the (2) factory mounting holes. Drill both holes out to [23/64"]. Prime them with rust-inhibiting primer and let it dry. Install 1/4-20 rivnuts.

    4. Install the D-overhead. Hold the trim piece in place and secure it to the sheet metal with 1/4-20 bolts.

    5. Prep for the D-pillar verticals. Hold each trim piece in place and mark the (4) factory mounting holes. Install M5 rivnuts in at least [2] holes.

    Optional (not included): larger rivnuts in these holes, or additional 5/16" rivnuts on the lower interior side of the pillar.

    6. Install the D-pillar verticals. Hold each trim piece in place and thread M5 bolts into the rivnuts. Before fully tightening, check that the shoulder where the vertical meets the overhead lines up cleanly. Then tighten, and fasten the top wall flange to the factory sheet metal with a self-tapping screw.

    7. Assemble the master rails. On a work surface, join the rail sections to full van length using the top and bottom mending plates. Hold each plate on the back side of the rail and fasten it with the provided 3/16" rivets. [Dry fit the rails in the van.] Now is a good time to paint or upholster.

    8. Install the master rails. Use the indexing marks on the ceiling struts to position the rails. Fasten them through the smaller holes into the struts with self-tapping screws. The struts can float from the factory, so keep the rails 50.75" apart [edge to edge], or 25.375" from the van's centerline.

    9. Secure the PS B-pillar. Remove the clamp and fasten into rail with self-tapping screw.

    10. Install the DS C-pillar. Tuck the back corner under the rail and let it hang so it self-indexes against the floor bend. Fasten it to the wall through the factory holes with self-tapping screws.

    11. Install the PS C-pillar. Use the shape of the factory sheet metal, weather stripping and the rail cutout to position it. Once it sits well against the rail and overslider trim, fasten it through the wall flange with self-tapping screws. Use additional self-tapping screws at the top where needed to tie in the C-Pillar, overslider and rail. 

ProMaster Full Kit Installation Video

Watch the complete install below, or follow the written steps above.

Mounting Hardware PDF

Here's a fastener location diagram. It clearly displays where the truss screws, M5 rivnuts, and 1/4-20 rivnuts/bolts go on the ProMaster Rail and trim kit.

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