Double-Hinged Seat Back Storage Access Mod

BrianZBrianZ Member Posts: 1,763
edited November 2023 in Modifications & Upgrades
Well, I have wanted to do this for a long time, but the examples I had seen were either for a different seat hinge, or the method looked questionable to me or short on details.  There have been at least a couple of discussions here..
Then I saw this video by an engineer, Mark, whose design looked pretty solid to me.  It required welding, but I was willing to pay a shop to do that..
So, I just finished, and here is my result - easy access to that rear storage area - just grab under the middle of the seat back & pull up!..

The seat back raises up from the 40° position to as far as the cabinets above permit, which is enough to rotate our table underneath to hold it up.  Our hinged wire shelves over the floor storage bins can still be raised, either before or after lifting the seat back.
Below is the sheet I printed & gave to a local welding shop showing the parts & how they were to be assembled.  

I bought two 3-ft flat 3/16 x 1-1/4" steel bars at Lowes, plus two 3" hinges (~$25); and cut them with a hack saw to make two 15-1/2" plus two 7" long pieces, as specified in the video.  I used a 1/4" drill bit for steel to make the 6 screw holes in the short pieces, lining up 3 of them with those in the hinges.
Here is the completed welding job with right & left hinge assemblies, which I spray-painted with a metallic silver rustoleum..

I think they did a great job - ready the same day and took 1-1/2 hrs, for which I paid $80 (more than I expected, but worth the cost IMO).
Here's a closer view of the nice welding job they did..

The only thing they could have done better was lining up the holes with those in the hinges, but close enough - only had to redrill a couple of them just to enlarge a bit.
I was all set to install them, but next was the only "gotcha" that I hadn't expected - the same hinges wouldn't fit back into the same space where they were previously mounted, because the new angle of approach was going to be 90 degrees to the old mounting and there was a wood ledge on the frame in the way, which needed to be removed.  See the before & after below..

This became the most time consuming part, because I had to remove many staples from the entire side of the frame in order to retract the  upholstery enough to cut the wood.  See below..

Before & after trimming wood to leave a notch at the corner of the frame.  I used a plunge-cut oscillating multitool to make cuts without damaging upholstery, but one could use a small hand saw, dremel tool, or chisel, and drill out the corner first.
Below shows how the fastened new hinge assembly fits into the newly notched corner of the passenger side seat back after the upholstery had been replaced..

I was also able to use the original screw holes to remount the hinges into the T@B.
Below is the remounted new double hinge in action..

The seat back is only attached at the top.  It works great, and is quite solid.
This view shows more what the view is like while actually using it.  Easy access now - Hallelujah!

The last time that I looked everywhere else for something that I eventually found in here, it was because this was the last place that I wanted to even try to look.  Now, there's nothing stopping me.  :)
Below are some of the special tools that were either necessary or handy to make the job easier..

The 3" wire wheel brush used on the electric drill was handy for cleaning up the steel bars prior to welding & painting.  I forget if that screw-driver looking tool with a claw at the end has a name, but it's very handy for pulling up staples. (staple remover thingy?)
[Edit:  Home depot calls it a "Tack Puller".]
I also gave a couple of taps with a hammer to each of the new 3/8" stainless staples after shooting them in.  You may also need to have either a vice or pair of screw clamps & work bench to hold the steel bars while cutting, filing, & drilling.  Cutting & drilling was easier than I expected, but you need a drill bit made for steel.
I recall reading Dale Helman's ratings of this project's difficulty three different times as either 3, 4, or 5 out of 5.  If you're handy with tools, have the patience, and don't mind the cost or can weld it yourself, then I expect this mod will be well worth the effort.  I just wish I could have done it sooner.

-Brian in Chester, Virginia
TV: 2005 Toyota Sienna LE (3.3L V6)
RV: 2018 T@B 320S, >100 mods 

Comments

  • jimrjjimrj Member Posts: 56
    @BrianZ.  Nice job!  NuCamp should adopt for 2023 models. 
    Jim and Robin / 2021 320S / 2015 Jeep Cherokee Trailhawk / Oregon
  • tybladesmithtybladesmith Member Posts: 178
    @BrianZ great writeup. I did this mod and also split the seatback with a set of hinges from Amazon that have a lower profile than the NuCamp hinges.
    I bought an electric stapler for this job. Totally worth it!
    Kay and Tom - SW Wisconsin - Silver T@bernacle - 2018 T@B 320S Boondock Silver/Black trim TV, 2018 Chevy Colorado, Silver/Black trim, Duramax, TowHaul, IntelliHaul
  • BrianZBrianZ Member Posts: 1,763
    That's great, @tybladesmith - the ultimate fix!  Which hinges did you use?  And did you need to alter the seat bottoms to fit the middle hinges of the seatbacks?  Did you or will you post here with photos showing how you did it?
    -Brian in Chester, Virginia
    TV: 2005 Toyota Sienna LE (3.3L V6)
    RV: 2018 T@B 320S, >100 mods 
  • BrianZBrianZ Member Posts: 1,763
    Thanks, @Sharon_is_SAM.  I have seen that, but it's not a split seat back, just double hinged with full back.
    -Brian in Chester, Virginia
    TV: 2005 Toyota Sienna LE (3.3L V6)
    RV: 2018 T@B 320S, >100 mods 
  • tybladesmithtybladesmith Member Posts: 178
    edited September 2021
    @BrianZ, You are right the above thread only addresses the outside hinges. 
    Amazon.com: Lheng A Pair Color Zinc Sofa Bed Bedding Furniture Adjustable 3-Position Angle Mechanism Hinge Hardware : Everything Else
    These hinges were used for the middle of each back cushion half. They are a lower profile than the 2018 320S hinges so don't poke up as high as the side hinges. Note: the split back cushions as well as the adjoining seat bottoms like over the Alde also need to be modified for clearance of all four hinges. Hundreds and hundreds of staples need to be removed. That is eight places where the upholstery is unstapled and wood removed for hinge clearance. An electric stapler is your friend. I also bought upholstery and backing from Dan - Weaver Upholstery - (name on cushion tag). Dan contacted NuCamp for fabric color match, before shipping. Splitting/sawing the back cushion in two required adding an additional board to the cushion frame with Krieg screws and glue. Extra fabric is required to wrap around the second back for stapling. Plan ahead - measure twice cut once! A @Dalehelman 5 project rating, and more than an all day job. I am not sure the split back was worth the effort.  This is why I did not post the split seatback mod. 
    But the double hinged single back seat is a great mod for access to the abyss. Maybe leave the split back for NuCamp or they make both mods as a standard feature. 
    Again @BrianZ a great mod and write up. Well done!


    Kay and Tom - SW Wisconsin - Silver T@bernacle - 2018 T@B 320S Boondock Silver/Black trim TV, 2018 Chevy Colorado, Silver/Black trim, Duramax, TowHaul, IntelliHaul
  • BrianZBrianZ Member Posts: 1,763
    edited September 2021
    Thank you, @tybladesmith, for your explanation & honest appraisal of the process.  I do have the Krieg drilling jig and pocket hole screws, but guess I'll have to mull this over.  I tend to agree that it may be of limited value for the added work & expense.  I have to admit, I can only think of maybe one time over the last 4 years when one of us was ready to sleep while the other wanted the seat back up to read.  On the other hand, if we had it, I'm pretty sure we'd make good use of it.
    Congrats to you though - that is a lot of work. But if you enjoy the satisfaction of figuring it all out, the challenge of doing the work, and get good use out of it, then maybe it is worth doing.  Thanks again, and for the new photo too.
    PS:  "the Abyss",  haha, that's a good one!  =)
    -Brian in Chester, Virginia
    TV: 2005 Toyota Sienna LE (3.3L V6)
    RV: 2018 T@B 320S, >100 mods 
  • fstop32fstop32 Member Posts: 361
    Good job @BrianZ and @tybladesmith!  You've been busy!  I've gone from trying to figure out how to get my T@b into the garage to selling the house and building on another piece of our property so I can have an 8' garage door and plenty of clearance.  I think it will get the nod for the most expensive T@b mod ever!  =):anguished:    But once done I can get back to real mods done out of the weather, assuming I'm not confined to a rubber room.
    DaveR middleTN - 2015 320S  /  TV 2003 Tundra 4x4
  • FreespiritFreespirit Member Posts: 131
    After months of procrastination, decided to undertake this mod. This mod is likely my favorite and adds functionality to the TAB that was missing. As @BrianZ noted is his documentation, I did have to cut the notch to make the modification work, and removed a total of 120 staples (total both sides) to expose the wood. My only other “gotcha” was a hidden nail in the board I found when cutting the second notch. Had to resort to a hacksaw to finish the job. 
    On a functionality scale I would rate this mod a 10 out of 10. 



    2020 TAB 320 U
    TV 2022 Highlander
  • Basil48192Basil48192 Member Posts: 255
    Nice work.  I considered it....but my 2021 has the split backrest...so it does make the storage area a little more accessible.  Thanks for sharing!
  • bjn2bjn2 Member Posts: 77
    Nice work.  I considered it....but my 2021 has the split backrest...so it does make the storage area a little more accessible.  Thanks for sharing!
    Our 2023 also has the split, but I'm doing the mod for both sides. It's still a pain to try and reach down into the storage bay over the backrests. Our hinges will require me to notch the cushion's corners in four locations, but we have upholstery staplers and other tools to make that job fairly easy. I may rationalize getting a basic wirefeed welder for this project as an alternative to renting or hiring the work out. 
    Utah-based
    2023 T@B 320 S Boondock
  • Yoshi_TABYoshi_TAB Member Posts: 365
    edited November 2023
    Hi @bjn2

    For your consideration...I did the mod on a split seat  w/o doing any welding or notching the seat.  Took only a few hours.  Works real well and a great mod.  

    You can see it at the link below  about 5 posts back and the attached short video.

    What do you consider to be your "Most Valuable" trailer mod? - Page 5 (vanillacommunity.com)

    https://youtu.be/gout5r-O3xU
    2021 TAB 320 BD
    2021 Jeep Grand Cherokee
    Southern Maryland
  • bjn2bjn2 Member Posts: 77
    @Yoshi_TAB, interesting! My cushions had the frame routed out to accommodate the the hinge point bracket that nests into the side of the cushion. The wood they left (to accept hinge screws) keys the cushion and would have prevented it from opening (or fully closing depending on the order of assembly). I made the necessary notches in our seatbacks tonight and got the upholstery restapled.

    I'll consider tee-nuts or perhaps rivets depending on how big a project the welding looks to be. I have some other welding projects I'd like to do, so picking up a cheap MIG welder is an option on the table. Looking at Black Friday deals.

    I was wondering about the wire shelving I saw in one of the retrofits. It looks like an interesting way to segregate the storage below from the space behind the seatbacks. But I'm not sure if that's something we'll need. Bedding and our awning are what we're putting there now.
    Utah-based
    2023 T@B 320 S Boondock
  • WayneWWayneW Member Posts: 187
    I took the same approach as @Yoshi_TAB for the mod but drilled and tapped the metal bar rather than use t-nuts. It takes some contortions to get things marked but overall it’s a relatively easy mod, and well worth it. 

    I combined this with the outdoor shower quick disconnect mod in order to eliminate that pesky hose that you have to snake into that area on the driver’s side if you stay with the stock setup. Now both sides have useable and accessible storage. 
    2021 320S BD
    2006 F-150
    Coeur d'Alene, Idaho
  • bjn2bjn2 Member Posts: 77
    @WayneW, our 2023's Nautilus has a shower quick connect and a coiled hose/sprayer that stores in the compartment. I just looked up the old style and can see why you'd go for that mod.
    Utah-based
    2023 T@B 320 S Boondock
  • Dame_plumeDame_plume Member Posts: 75
    @BrianZ We will definitely do that one!  My ribs get so bruised trying to squeeze behind that seat that people are starting to think that Mike beats me up  :)
    Sylvie and Mike, Ontario, Canada / 2020 Tab 320S (Charlie) / 2021 Chevrolet Colorado LT (V6) Enhanced Towing Package
    "The only place where you start at the top is when you dig a hole"
  • BrianZBrianZ Member Posts: 1,763
    edited November 2023
    @bjn2
    You were wondering about the wire shelving installed behind/below the rear seat back.  I first learned of it in 2018 where multiple people before me had done this mod, and I  subsequently documented all my details, based on the method of @Hymie for the hinges.  See here..
    https://tab-rv.vanillacommunity.com/discussion/comment/94576/#Comment_94576
    These shelves work great along with the double hinged seat back, as we normally roll up our bedding, lift up the seat back from the bottom & just roll it back there on top of the wire shelving.  That keeps it separate from the various things we store under there (which tend to be things we don't use as often).
    -Brian in Chester, Virginia
    TV: 2005 Toyota Sienna LE (3.3L V6)
    RV: 2018 T@B 320S, >100 mods 
  • bjn2bjn2 Member Posts: 77
    Thanks @BrianZ ! Your write-up and photos are excellent. I did some practice welding yesterday and I'm waiting on the steel I ordered to build our double hinges. Once we have that part of the project done, we'll look at how we'll use the storage space and think about the wire shelving option.
    Utah-based
    2023 T@B 320 S Boondock
  • vshumatevshumate Member Posts: 6
    It is my understanding that the storage behind the seat back can't be used for dense items because the heat is sent through that area.  We put small milk crates upside-down so there is airflow and put items on top of milk crates
  • elbolilloelbolillo Member Posts: 270
    @vshumate No reason those areas cannot be used for storage of dense items. The radiators for the alde are behind the lift up storage area and the heat flows up from the gap behind that.
    _____________________________________________________
    Ken / 2023 Tab 400 “La Bolita” (15,000+ miles) / 2021 Honda Pilot
    2024 - 1 Trip - 20 nights - 3 National Parks, 2 National Forests
  • vshumatevshumate Member Posts: 6
    elbolillo said:
    @vshumate No reason those areas cannot be used for storage of dense items. The radiators for the alde are behind the lift up storage area and the heat flows up from the gap behind that.
    Hum, we were told this by the dealer.  There is a need for air exchanges. 
  • AnOldURAnOldUR Member Posts: 1,272
    elbolillo said:
    The radiators for the alde are behind the lift up storage area and the heat flows up from the gap behind that.
    True, but you have to be careful not to block air from entering. The convection heat relies on good air flow both in and out.

    Stockton, New Jersey
    2020 nuCamp T@B 320S * Jeep Wrangler

  • elbolilloelbolillo Member Posts: 270
    @vshumate @anoldur You would have to seriously pack in a ton of material to restrict the airflow. Unless you pack in a bunch of material that absolutely restricts all airflow, you will be fine.
    _____________________________________________________
    Ken / 2023 Tab 400 “La Bolita” (15,000+ miles) / 2021 Honda Pilot
    2024 - 1 Trip - 20 nights - 3 National Parks, 2 National Forests
  • AnOldURAnOldUR Member Posts: 1,272
    A winter project was adding a fan under the bed to help the flow of air through the rear gap. Haven't had the chance for a camping test, but pretty confident that it's going to be a noticeable improvement.
    Stockton, New Jersey
    2020 nuCamp T@B 320S * Jeep Wrangler

  • MobeanMobean Member Posts: 50
    To avoid compromising airflow, you can also create a simple false bottom with thin plywood or melamine in both areas under the seatbacks.  Hot gluing stiff support material prevents collapse of the false bottom.  I have the quick connect set up for the outside shower so no need for the hose storage space.


    2021 320S BD
    2020 V6 Chevy Colorado
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