Installing a window in your camper van build can be one of the most intimidating parts of the process—but it doesn’t have to be. In this post, we’ll walk through a custom CRL T-Vent window install on the driver’s side of a Ford Transit, using an Adventure Wagon bump out and a few custom tricks to make the finish look seamless and professional.
Whether you’re a first-timer or an experienced van builder, this guide will give you the insight and confidence to tackle this project with precision.
Why Install a CRL T-Vent Window?
CRL (C.R. Laurence) windows are a popular option in van builds for their clean look and excellent ventilation. The T-Vent style offers a sliding panel with a screened opening—perfect for air flow while keeping bugs out.
For this install, we’re using the CRL T-Vent on the driver’s side of a Ford Transit, paired with an Adventure Wagon bump out. The goal? Increase usable interior space and add a professionally trimmed window.
What You Need Before Cutting Into Your Van
Template Materials
- Cardboard (to trace the window shape)
- The original box the CRL window came in (makes for a perfect tracing tool)
Tools
- Jigsaw (fine-tooth metal blade)
- Drill + drill bits
- Cut-off wheel (for vertical steel supports)
- Painter’s tape
- Grinder
- Marker or pencil for tracing
Safety + Cleanup
- Welder’s blanket (for spark protection)
- Plastic wrap and tape (to cover interior surfaces)
- Vacuum for metal shavings
Step-by-Step CRL Window Install (with Bump Out)
Step 1: Create a Cardboard Template
Use the box your CRL window came in to trace out the exact frame size. Cut it clean with a razor and use this as your primary template.
Pro Tip: Don’t rely solely on Ford’s factory stamp cut lines—they can be up to ¼” too large, which might lead to leaks.
Step 2: Transfer the Template to the Van
Drill reference holes through the cardboard template from the inside of the van. This helps align the cut from the outside, which is easier for maneuvering the jigsaw.
- Drill holes in 2–3 key spots
- Tape the template to the outside of the van
- Trace the window cut line from the outside
Step 3: Deal with Internal Support Members
You’ll notice vertical support members made from a harder steel behind the sheet metal. These need to be removed:
- Use a cut-off wheel to carefully slice through the top of the supports without damaging the van skin
- Remove adhesive-backed supports gently to avoid denting the sheet metal
- Grind and smooth the area as needed
Step 4: Cut the Window Hole
- Double-check that your cardboard template fits flat
- Drill two large holes to start your jigsaw cuts
- Carefully cut along the traced line (stay just outside the line to allow wiggle room)
- Tape off the area to protect from scratches
Step 5: Test Fit the Window
Hold the CRL window up using painter’s tape to check for alignment and fit.
If needed, make small adjustments:
- Watch the bottom body line—the window should be parallel to this line
- In our case, the top right corner needed about ⅛” more material removed to align properly
Upholstering and Trimming the Adventure Wagon Bump Out
The Adventure Wagon bump out provides a bit of extra depth, but not enough to transition cleanly to the window frame on its own. We needed to create a custom trim solution to bridge the gap between the window and the bump out.
Trim Solution
- Use your cardboard template to trace a new trim ring from ¼” plywood
- Extend the outer ring dimensions to cover the CRL window’s mounting flange and screw heads
- Upholster this trim ring and attach it to the bump out panel for a clean, finished look
Note: Marathon fabric used for this was backordered at the time of install—plan accordingly if you want a seamless upholstery finish.
Common Issues and Mistakes to Avoid
- Overcutting the window hole – Always cut small and adjust
- Ignoring the Adventure Wagon scribe line – Follow it closely for better alignment
- Cutting the panel corners too aggressively – Can ruin a $500 panel
- Forgetting to protect interior surfaces from sparks and shavings
Helpful Links from the Video
- How to Tap Threads in a CRL Window
- T-Vent Sliding Door Install Video
- Camper Van Window Bump Out Video
Bonus: Free DIY Van Build Cheat Sheet
Looking for an organized, Amazon-linked gear list that’s been tested in real van builds? Download our DIY Van Build Cheat Sheet with 250+ items across:
- Electrical
- Lighting
- Kitchen
- Tools
- Storage
- Plumbing
- Fasteners & more
Download the free cheat sheet at VanBuilderHQ.com
Want a Pro to Build It for You?
If you’re looking for a custom professional van build by Nick himself, visit OdysseyCustomVans.com. Fill out the contact form, share your vision, and let’s chat about your dream van.
Final Thoughts
Installing a CRL T-Vent window in a Ford Transit isn’t as scary as it looks—especially with the right prep, tools, and guidance. From precise templates to trim solutions for bump outs, this guide should set you on the right track for a clean, pro-level finish.
Have questions about your install or upholstery solution? Drop them in the comments or reach out to us through VanBuilderHQ.com—we’re always looking for new ideas to turn into future tutorials!
