This document outlines a DIY method for creating low-profile crossbars for a 2003 Prado VX turbo diesel 4-door, utilizing the existing OEM roof rails. The aim is to reduce wind resistance and improve the aesthetics compared to traditional roof racks, while maintaining flexibility and strength.
Problem
The need for a low-profile roof rack that utilizes the existing OEM roof rails, offering adjustable positioning for carrying items like surfboards and luggage.
Solution
Fabricating custom crossbars that attach to the OEM roof rails using the internal channels of the rails. This involves creating metal components that slide into the rail channels and provide a base for the crossbars.
Key Steps:
- Design and Fabrication: Design and fabricate the following components:
- 4 flat pieces (7.5cm x 2.5cm x .5cm) with two threaded holes.
- 4 angle pieces (7.5cm x 3.0cm x 3.0cm) with two holes matching the flat pieces.
- 2 crossbars (99.6cm x 1.9cm).
- Channel Access: Access the inside channel of the OEM roof rails by partially disassembling the rail system. This might require removing the front or rear base of the rail.
- Component Insertion: Slide the flat pieces into the inside channel of the roof rails.
- Assembly: Attach the angle pieces to the flat pieces inside the channel using bolts, washers, and lock washers, effectively “sandwiching” the rail edge between the components.
- Crossbar Attachment: Weld the crossbars onto the horizontal part of the angle pieces.
- Shimming: Use plastic shims to compensate for any height differences between the front and rear rails, ensuring a level crossbar.
- Reassembly and Installation: Reattach the rail bases and reinstall the entire assembly onto the vehicle’s roof.
- Final Adjustments: Loosen the bolts securing the crossbars and slide them forward or backward to accommodate the load.
Relevant Parts and Dimensions
- Flat Pieces: 7.5cm x 2.5cm x .5cm, with two threaded holes.
- Angle Pieces: 7.5cm x 3.0cm x 3.0cm, with two holes matching the flat pieces.
- Crossbars: 99.6cm x 1.9cm (Recommended: 2.5-2.7cm diameter bars for a flush look)
- Bolts: 2cm threaded length, 10mm head, with lock washers and washers.
- OEM Rail Attachment Bolts: 12mm wrench size.
- OEM Rail Screws: Tor30.
- Inside Channel Dimensions (OEM Rail): Roughly 2.6cm x 1cm. Outside height is 3cm.
Tools Required
- Plastic curved tool (bike tire levers) for removing base end caps.
- 12mm wrench for base bolts.
- Tor30 wrench for rail screws.
- Welding equipment.
Additional Notes
- Consider using thicker flat pieces for more thread engagement and longer lengths for increased surface area contact within the rail channel.
- Zinc primer or electroplating is recommended for corrosion protection, especially in humid environments.
- Be careful when working with the Tor30 screws, as clearance can be limited.
- The front base blocks part of the outside channel, but only requires removal of one base to insert flat pieces.
This technical summary was auto-generated based on recovered archives. Do not rely on its factual accuracy. Refer to the original thread. Source: View Original Conversation
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