Cavernous Crewmax DIY underseat storage

Built my own backseat storage for my 2021 Crewmax. The hardest part was cutting into a brand new vehicle but I needed the space.

Combined two ideas from this forum:
- A hard frame that follows the perimeter of the seat
- Sunken steel dishes to serve as storage bins

Advantages:
- Space is maximized since there are no dividers, spacers or bezels
- Cost is minimal compared to commercial offerings
- Very easy to do, no need to cut the metal seat bars under the felt

The Frame:
- 52.5" width, 12.5" depth, 2" high, 0.75" frame thickness. I used oak, pine would save money. (Ripped a nominal 1x3 oak plank, resulting size 0.75" x 2")
- The side posts butt up against the seat mounts on each end with a 0.5" relief cut to allow them to side flush against the seat mount flange and also the floor
- A piece of aluminum 1.5" x 19" long permits the frame to be bolted to an existing unused hole located within the end seat mounts. No drilling required (except of course in the aluminum bar.)





The Bins:
- Purchased two full size 2.5" deep steam trays, one half size tray
- The driver's side tray fit perfectly between the seat mounts
- The middle tray is somewhat long and I encountered a metal bar under the foam toward the back. Ended up having to cut a small relief hole in the tray. We are limited by the seat belt mount in the floor, otherwise the tray could have been moved to the other side of the space.
- The passenger side half size tray fit perfectly. In the back we have the factory jack storage in the way but the tray does not interfere.





Imgur is giving me trouble with uploads, will add pics of the build later

 

The frame when it is not bolted to the seat brackets



Yes, it's big enough to hold an AR15. The seats are 'hollow' underneath and the charging handle only sticks out about a quarter inch above the frame. You could fit something much larger there if needed.



Bracket detail. The frame is 2" high, the aluminum bar is 19" long and extends to the seat bracket.
Note the 0.5" relief cut that allows the end of the wooden frame to sit both on the floor and the seat bracket flange.

 

The bins:
- Two 'full size' 2.5" deep steam pans. Amazon.
- One 'half' size steam pan
- Painted flat black



Cutting:
- Removed seats, there will be residual outlines of the brackets pressed upon the fabric for reference
- Marked all outlines with a fabric grease pencil
- Used the inside edge of my frame as reference
- Placed the bins between the brackets and butting up against my frame
- Traced the outside of the bottom of each bin. Do not cut along this line, the trays will not fit.
- Added 0.5" margin and traced another outline (curve each corner.) This is your cutting line.
- The trays have a 0.75" lip on all side so you'll end up with a snug fit for the tray and and overlapping tidy finish
- Use a sharp shop knife, the carpet and underlying 0.5" thick fluffy material cut easily
- I used a Cutco avocado knife to cut out the 2.5" thick styrofoam. Some use a carpet knife or steak knife.





Note: Here's the pipe I encountered under the foam of the middle area. Either get a smaller bin, change your design to move the bin 2.5" toward the front of the truck, or cut the bin as I did.





I took the fluffy material from each carpet piece and placed it under the bins for stability. The remaining top layer of the carpet went back into the bins after trimming. This also covered up the relief cut I made into the middle bin.

 

I would add some sound deadening under those bins as they would amplify road noise-like a speaker.

 

There is a 0.5" layer of the factory sound insulation under each bin. You'll see it if/when you tear up your carpeting.

There is no noise difference as far as I can tell, my passengers can't tell a difference either. (FWIW I now have a thick layer of cargo in there as well)

 

What I keep in the back:
- Two pairs of gloves (one thick, one thin)
- Socket set, screwdrivers, wrenches, pliers, hammer
- Duct tape
- Full roll of paper towels
- Pack of wet wipes
- Flashlights, zip ties
- Can of tire seal/inflator
- Mid-size fire extinguisher
- 1st Aid kit, large box of band-aids
- Two kinds of rope/string
- About 6 sets of tie-downs
- Emergency rations
- Bottles of water
- Jumper cables
- Costco soft freezer bag
- Two umbrellas (one full size, one compact)
- Space blankets
- Regular blanket
- Small folding shovel

Still need to add some kind of tow strap

 

nice quick build!

 

Nice build. Any pictures of the relief cut for reference?

Instead of scooting that particular tray towards the front, could it be shifted towards the passenger side? I see a cut in the carpet there not sure if that's where something bolts down or what???

Not around my truck to go look.

 

Very nice !

 

Great job! I've held off on buying the ESP storage and like the idea of going this route. Any rough estimates on total cost for this build? Where did you get the side aluminum pieces?

 

Very nice! This might be my next weekend project.

 

Partly covered by carpeting:


This is the size of the cut in my tray:
- Measure 1.5" from the top of the tray and mark the side (this will be the 'top' of the cut)
- Measure 2.5" from the end of the tray and mark (the 'end' of the cut)
- Make the cut 1" deep, from the long edge of the tray

This should yield a 1x1x2.5 rectangle to be removed. At first I tried to just beat a dent into the tray with a ball peen hammer but the stainless steel is pretty tough.

Yes, but you'd overlap with the seatbelt mount. I think it could be done since the seatbelt has an "L" shaped bracket that is not indexed, thus you could loosen the bracket and swivel it around to face the left (and tighten back down.) Then the tray could sit directly over it while still allowing the seatbelt to sneak past the lip. I'd make sure to provide about a half inch clearance so the belt isn't rubbing against the tray.

If I were to do it again I'd definitely try to move the tray around to make it all fit before making any cuts. I had no idea I'd find a pipe under the foam, previous builds haven't mentioned it but I did see it in one of the pics where someone ripped out _all_ the carpet and foam as part of a different project. Now we know where it is, LOL!

The wood, aluminum and hardware was all from Home Depot. I didn't sand or scuff up the aluminum prior to painting but I think would have been a good move, it's pretty slick. My frame is easy to pop off for painting if needed, I used black Allen bolts with a little knurling on them, the mounts are just finger tight (ie. the end that connects to the existing factory bolt holes found in the chair brackets.)

Cost:
- Oak = $30 (would be $4 with clear pine or poplar, just rip a half inch strip from the width of a 1x3 board and you'll end up with 0.75x2 actual size)
- Aluminum maybe $10, I went with 19" strips on both ends but you could get away with shorter pieces, even 6" if you wanted
- Hardware = $10, but could be free if you use stuff laying around in your garage

The bins were $11 for the small one, $20 for each large one from Amazon. Someone provided links to Sam's Club where they had 2-packs of the large bins for $22, but I'm not a member.

Total could be around $70 if using pine and less aluminum, I probably spent close to $100. If you use scrap materials in your garage then it's just $50 for the bins. Oak provided a good look and excellent durability, that's why I used it.

 

@BrakeDust - Would the 4" deep steam pans fit?

 

Nice!! Did this years ago best mod i have done

 

If I didn't have an ESP system sitting at home I would definitely be down for this one! Great mod!

 

Yes, but then you must add a 1.5" bezel around it to cover the projecting lip. The styrofoam is about 3" thick in most places and tapers off to about 2.5" at the back. Many people have 1.5" thick sheet/board in the area under the seat and sunk their 4" pans. I didn't want to lose the extra space.

 

Got it, thanks for the explanation. Was just curious since the ESP one is 4".

 

The ESP version comes with the bezel included. It's a nice turn-key solution but the plastic version doesn't offer very much space IMO. The gun safe is much larger but requires very extensive surgery to the vehicle - and it's very expensive.

 

Awesome job! I might have to steal this exact design once we don't have a foot and a half of snow on the ground.

 

That's super smart to use the steam pans! Never would have thought of that! Looks great!

 

“Still need to add some kind of tow strap”

Might I suggest a Freedom Recovery Rope? Not sure if I’m allowed to share the link here so if you want it just ask and I’ll provide it. They are awesome kinetic ropes with soft shackles that are exceptionally effective.

I was actually looking for ideas on how to store mine when I stumbled across this thread. Great storage ideas! I think I’m going to follow your lead and implement this in my first gen Tundra.

 

Share away Lisa. That’s part of how we all end up over new mods!

 

Thanks! I’m brand spanking new here and didn’t want to piss anybody off LOL!

www.freedomropes.com

These things are amazing! The company is local to me here in Oceano, Ca (Pismo Dunes) and use kinetic energy in a highly efficient manner. I love the soft shackles; no rub or wear from metal connections and they store in a nice soft, lightweight custom bag. So glad I ran across the owners on the beach one day; they work great!

 

Very cool post @BrakeDust
Thanks for sharing!

 

Great idea for sure. I've pondered doing this before. The link to the "Steam pans" doesnt work, so could you supply some dimensions? Thanx. Im going to do this for the extra storage under the seats.

 

Thanks for sharing, I’m going to try this

 

Anybody know what that tube is?
Anybody have a pic of the smart key antenna wire to see if this mod is possible before I start cutting.

 

I went with the ESP. Total time spent 40 minutes. Would have gone quicker but I was so worried about the wiring for the smart key that I just kept creeping up on it with the knife. Very happy with it, much more expensive than the OP design I’m sure..

 

If you are cutting the middle section, the sensor is in the front right corner if you are staring straight down at the hole. Remove 6-7 inches from the left and start working your way towards the drivers side.