Before cutting or drilling anything, map out the complete installation on paper and then on the vehicle floor. Poor layout planning is the most common cause of do-over installations. Decisions made in Step 1 affect every subsequent step.

Determine wheelchair position location

In most rear-entry NEMT vans, the wheelchair position sits forward of the lift — typically with the wheelchair facing forward and positioned so the rider's head is toward the front of the vehicle. The rear tie-down points must be accessible from beside or behind the occupied wheelchair, and the forward tie-down points must be accessible from the forward side.

Mark the floor where the wheelchair's four wheels will sit for your most common wheelchair type. This is your reference point for everything else.

Determine track run positions

L-track typically runs in two parallel channels — one along each side of the wheelchair position — oriented front-to-back (longitudinally) in the vehicle. This gives you forward and rear retractor attachment points along each side of the wheelchair.

The track runs should be positioned so that retractors can attach at the correct distance from the wheelchair frame tie-down points. A common starting reference: track centerline approximately 12–18 inches from the vehicle centerline on each side, adjusted to match your wheelchair footprint.

Check for floor obstructions

Before marking drill locations, identify what is beneath the floor surface at each intended anchor location. Check for:

• Fuel lines, brake lines, and electrical wiring runs
• Fuel tank location (varies significantly by van model and tank size)
• Frame crossmembers and floor joists — these are your target anchor points
• Existing floor reinforcements from the vehicle converter

Mark your track mounting hole locations

L-track must be anchored through the vehicle floor into structural members — frame rails, crossmembers, or reinforced floor sections — not into the floor sheathing alone. Mark anchor hole locations at a maximum of 12-inch intervals along the track, with anchor points at or near each end of the track section. More anchor points mean better load distribution.

With your layout marked, prepare the floor surface and cut anchor holes. Work methodically — mistakes at this stage are expensive and time-consuming to correct.

1. Remove existing floor covering in the installation zone if present — carpet, rubber matting, or vinyl. L-track must sit flush against the structural floor surface, not on top of soft flooring material.
2. Inspect the subfloor in the installation area. Look for existing reinforcement, prior installation holes, or signs of corrosion. Address any corrosion before proceeding.
3. Drill pilot holes at each marked anchor location using a small bit first, then confirm from underneath that the location is clear of lines and wires before opening to full size.
4. Open anchor holes to final size per your mounting hardware specifications. Most L-track mounting hardware uses 3/8" or 1/2" bolts — confirm with your specific track and hardware.
5. Treat all cut edges immediately with corrosion-inhibiting primer or sealant. Bare metal edges in a vehicle floor will rust, and rust compromises structural integrity over time. This step is frequently skipped and always regretted.
6. Install backing plates from underneath at each anchor location if your floor structure does not provide sufficient material thickness for thread engagement. Backing plates distribute the anchor load across a larger area of the floor structure.

With floor prep complete, mount the track channels. The quality of this step directly determines the safety of every securement made in the vehicle for the life of the conversion.

1. Dry-fit the track before final installation. Confirm that all anchor holes align, the track sits flush, and nothing obstructs the track channel slot along its full length.
2. Apply sealant to the underside of the track where it contacts the floor. This prevents water intrusion at the contact surface, which causes corrosion over time.
3. Insert mounting bolts from above through the track and floor into backing plates or nuts below. Hand-tighten all bolts before torquing any of them — this ensures the track seats evenly.
4. Torque all bolts to specification. The correct torque value is specified by your track and hardware manufacturer. Do not estimate — use a torque wrench. Under-torqued bolts will loosen under vibration. Over-torqued bolts will damage the track or floor material.
5. Install end caps on both ends of each track section. End caps prevent the track slot from catching on clothing, equipment, or the tie-down hardware, and give the installation a finished appearance.
6. Install filler strips in any open track sections between or beyond retractor positions if desired. Filler strips cover unused track slots and reduce debris accumulation.

Track mounting torque reference

Always defer to the specific torque values in your hardware manufacturer's documentation. The above ranges are general reference only.

With the track installed, position your wheelchair in the vehicle and determine where the four retractors will attach. This is not a fixed formula — correct retractor positioning depends on the wheelchair's tie-down points and the required strap angles for WC18 compliance.

The 4-point tie-down geometry

Each wheelchair position requires four retractors — two forward (attaching to the front frame of the chair) and two rear (attaching to the rear frame). The retractors attach to the L-track via L-track fittings and connect to the wheelchair via strap hooks at the chair's designated tie-down points.

To achieve the correct strap angle, the retractor's floor attachment point needs to be positioned at the right distance from the wheelchair's tie-down point — far enough away that the strap runs at the correct angle, but not so far that excessive strap length creates slack management problems.

Practical positioning method

1. Position the wheelchair in the vehicle at its intended securement location.
2. Hold a strap from the chair's front tie-down point toward the floor at a 45-degree angle toward the front of the vehicle. Mark where the strap hook would contact the floor — that is approximately where the forward retractor fitting should sit on the track.
3. Repeat for the rear tie-down points, angling toward the rear of the vehicle.
4. Mark all four retractor positions on the track. These are your starting points — fine-tune after a test securement.

With retractor positions determined, install the L-track fittings and retractors, then perform a complete test securement to verify geometry and function before putting the vehicle in service.

1. Insert L-track fittings into the track channel at each retractor position. Rotate the fitting 90 degrees to lock it into the track. Confirm the fitting is fully seated and locked — a loose fitting that has not fully engaged the track is a critical failure point.
2. Attach retractors to fittings per the retractor manufacturer's instructions. Most retractors attach to the L-track fitting via a bolt or pin connection. Confirm the connection is secure before loading.
3. Position the wheelchair in the securement position.
4. Extend each retractor strap and attach the strap hook to the wheelchair's tie-down point. Use the manufacturer-specified attachment method — most hooks have a locking mechanism that must fully engage the tie-down point before the strap can be tensioned.
5. Allow the retractor to take up slack. The strap should tension automatically as slack is released. Confirm the strap is taut and the hook is fully seated at the wheelchair tie-down point.
6. Verify strap angles. Each strap should run between 30 and 60 degrees from horizontal. Straps running too flat (under 30°) have poor forward restraint. Straps running too steep (over 60°) create excessive upward force on the wheelchair frame.
7. Install the occupant restraint — lap belt and shoulder belt — and confirm both are correctly routed and latched.
8. Perform a manual pull test. With the system secured, apply firm manual force to the wheelchair in the forward direction. The system should hold without movement, strap slippage, or fitting rotation in the track.

The wheelchair tie-down secures the chair. The occupant restraint — lap belt and shoulder belt — secures the rider. Both are required for WC18-compliant installation. The shoulder belt anchor point is the element most often compromised in DIY and under-supervised installations.

Lap belt anchor

The lap belt anchors at or near floor level on both sides of the wheelchair position. In many installations, the lap belt anchor is integrated into the L-track fitting system or bolted into the floor in a fixed position beside the track. Confirm your specific retractor and occupant restraint system's lap belt anchor requirements before installation.

Shoulder belt anchor — the critical element

The shoulder belt must anchor at a upper anchor point — typically at or above shoulder height — to route the belt correctly across the rider's chest and shoulder. Common upper anchor locations in NEMT van conversions include:

• The vehicle's C-pillar or D-pillar (rear structural pillars)
• A dedicated upper anchorage post bolted to the vehicle floor and sidewall
• A wall-mounted bracket anchored to the vehicle's structural framing

The shoulder belt should route from this upper anchor across the rider's chest — not across the neck, and not under the arm. A shoulder belt that routes from too low an anchor point (below shoulder height) does not provide meaningful crash restraint and may cause injury in a sudden stop.

Before the vehicle goes into service, complete a final inspection and document the installation. This documentation is your protection in the event of an audit, an insurance claim, or a liability situation.