Cracked Pinch welds under bed (!!)

I have been chasing a rattle for some time and found the bed ripping apart just before my camping trip this weekend. I sent pics to @eccracer104 and he sent me this thread. I have a 2020 double cab with a SnugTop Super Sport shell and I mildly off road. The pics are of the driver side where I notice the bed moving more and where I heard the rattle, I’ll do a full inspection soon.

 

No cracked bed here.

 

Do you have a double cab?

 

Please consider joining this FB group I created and share your findings/pics.

 

This should have never happened; Toyota really pooped the bed on this one. I really feel for anyone suffering from this issue!

 

To add a little bit more detail into how the bed is constructed at these cross members - I recently completed a bed floor rust repair project on my 07 with a donor 2015 bed and investigated the layers a bit further. The frame/bed flexing design is definitely related to the bed floor rust issue as it opens up the metal between layers leading to relative motion between the bed floor and cross member layers, as well as exposure to the elements/salt to cause corrosion.

https://frugalfill.com/2nd-gen-toyota-tundra-bed-floor-rust-repair/

There are actually 3 layers of material at the 4 major (outer) bed bolt areas.
1.) the crossmember itself, a c-channel assembly with some welded thru bosses for the bed bolts to run through. 2 per bed fore and aft the wheel wells (blue)
2.) a flat plate that is slightly wider than part 1 and extends inboard past the frame but not fully across the bed. There are 4 of these per bed, 2 per major cross member. Presumably to help spread the load to the bed floor near the outer bolts (red)
3.) the corrugated bed floor (green)

These three layers are spot welded together sparingly, and seam sealed poorly. On both of my beds there was wild variation in the factory seam sealer application, as well as areas between layer 2 and 3 that were left wide open at the bed floor corrugations. I'm not surprised to see the seam sealer separating at the ends of the #2 "weight distribution plate" like this. The bed floor is floppy, the plate is rigidly attached to the cross member. Some flexing up and down of the bed rail would bend down the plate and tear the seam sealer.

The bed floor is constructed of three pieces: A bed wall including wheel well and the "outer" bed bolt areas shown here, a flat center bed floor section with "inner bolts", and the other bed wall. I'm not sure if this construction is good or bad for the bed support tearing issue, maybe bad since any bed rail weight is essentially trying to fold the bed side off of the center section that is inboard of the bed bolt? Or good since the bed bolt is holding the bed side more rigid (on the twerking frame...).

 

Definitely would get this looked at by Toyota. Only caveat is tire rub on the bed, it will push the bed up. Easy enough to see witness marks from contact if that’s the case.

Have seen double cab and crew cab beds crack exactly the same.

Quick check appears the on-road dynamic weight rating of your rack is 400 lbs.., does not list dynamic off-road weight for your bed cover equipped version, but the option without the bed cover is 1/2 of the on-road dynamic weight for off-road. Looks like the worst damage is directly under the storage compartment box, looks heavy, maybe too much weight on that corner? Rough math on what you have on the rack is definitely over 400 lbs., does the weight of the rack, cover, and accessories count towards the rack weight rating?

 

Crewmax

 

Literally just spot welded? Unbelievable! This is a really helpful breakdown of what's happening. To my eye the passenger side on my bed looks much better structured, and I'm struck by the fact all the problems reported so far have been driver's side.

I have an appointment to get my bed cracking looked at by SDHQ here in Phoenix on 2/2. Tell's you how much confidence I have the dealership will be of any help, but I'll probably have them look at it too. Has anybody else had any input from dealers or fab shops on fixes, other than frame boxing?

 

There’s no seam welding in modern vehicles that I am aware of. Pretty much everything is either glued or spot welded.

 

here's the spot welds that are under the "cracked" seam sealer in the original pics in this thread. If they aren't torn apart it might just be as easy as applying a new coat of seam sealer and reducing the bed rail weight and carry on.

 

I spoke with corporate. They advised that they can’t do anything since I am outside of warranty. They suggested I create a ticket with NHTSA. I urge everyone to do the same so there are multiple documented issues.

 

Like I need more of reason to backhalf my rig lol bye bye bed lol

 

Well this post made me look at mine. 2017 DC that always has my ARE CX cap on. The cap isn’t as heavy as a camper of course but it’s probably 200-250 lbs given it’s a more loaded model. 63k miles, no signs of any cracking/damage yet but I’m also not flexing the crap out of it off-roading or anything. The bed does get loaded somewhat heavily several times a year for camping trips and firewood hauling. I’ve also been spraying the bottom of the bed with woolwax the past few years to help prevent the bed rust issues. Oddly my bed sealant even prior to the woolwax is black and not white.

 

So, The Angry Camper (of the video I posted earlier) has done this as a bit of a fix — added some bracing from the frame up to and across the front of the bed. Curious what folks think of this as a fix. I’m wondering if that just transfers the torquing of the frame as it flexes even more to the front of the bed?

https://youtu.be/NK_ugEv6E8I?si=FoBZa8MKJkLIIcBn

 

@blackoutt covers this very well. It is the same problem that caused the rust issues on the earlier trucks.

 

where does he cover it?

 

Post #66.

 

Very weird.
I see post 65 and post 67. No post 66.

 

Overlarper problems.

If you havent bought a welder and learned how to use it i suggest doing that.

 

https://www.tundras.com/threads/flatbeds-are-possible-on-a-tundra.113052/

 

Wow after reading that thread it sure has me concerned about the bed rails supporting weight. Was fixing to mount a 1000lb 6 hole aluminum framed with stainless doors dog box on my 2018 long bed TRD.

I'm no engineer or mechanic, but I've been known "rig/macgyver" some things.. has anyone just filled this gap with a block/wedge or some sort and welded it in?
Seems like something can be mounted on the driver side front to help support it..I can't be the only one who thought about this when I saw and read this post?

Thanks, Jeff

 

Wow after reading that thread it sure has me concerned about the bed rails supporting weight. Was fixing to mount a 1000lb 6 hole aluminum framed with stainless doors dog box on my 2018 long bed TR
I'm no engineer or mechanic, but I've been known "rig/macgyver" some things.. has anyone just filled this gap with a block/wedge or some sort and welded it in?
Seems like something can be mounted on the driver side front to help support it..I can't be the only one who thought about this when I saw and read this post?

Thanks, Jeff

 

check this out for issues, and possible resolution

 

So, after thinking a lot and getting a lot of feedback, I managed to get a fix for the bed that I’m happy with and THINK will last, at least for quite a while. I took a two week trip with a lot of highway, and a significant amount of unpaved roads, some with off camber and washboard run at higher speeds, more significant off camber and some small ledgy stuff. About 60 miles of the latter. The fix has held up well so far, so thought I’d post what I did.

Essentially, I sandwiched the bulge and the cross brace together and through bolted. I used 3/16 5052 aluminum (best strength plus flex with cracking resistance according to Industrial Metals) with some details I’ll mention with the pictures. I had 4 sources look this and this was their consensus, which aligned with my initial idea, but with some helpful suggestions. The sources were: SDHQ, a good local body shop that does a lot of Tundras, my usual mechanic, who was a Toyota master mechanic, and a neighbor/friend who happens to be a structural engineer.

First of all, no one wanted any part of actually fixing this. I could have talked SDHQ into it, but it was $3 to $4K and they would have had to remove my camper and bed, which, right now is a deal breaker. They also really thought it didn’t make sense vs putting the money to a flat bed. They suggested a 3/16 aluminum sandwich.

Everybody agreed that a) the bed would continue to flex, b) I needed to allow for some movement, but control it, and c) part of the cause was that the bed stiffeners in the rear, the bedrail mounted camper rigidity (NOT weight as it’s 400 lbs) and some of how I built some internal structure that stiffened the passenger forward corner more than the driver side forward corner all created more movement on the D-side forward corner, where the bulge is and the spot welds ripped.

This is the damage I found inside once I pulled up my Bedrug. It was dustier before cleaning, but only through the ripped spot welds. The internal bed had not ripped . . . yet. I was fortunate to find it sort of early. You can also see how off the spot welding was. This is part of the problem — the outer two most spot welds are right on the edge of the cross brace underneath making it easier for them to rip.


This is bottom piece of the sandwich that goes underneath. To allow for some controlled flex, this is longer than the internal top piece and goes from the main cross brace to a minor stiffener brace almost at the front of the bed. You’re seeing this as if you’re looking down through the bed.
The notch on the right (which is P-side) is to clear another weird little stiffener brace underneath



This is the whole sandwich as it’s going to be stacked in the bed, with the steel bed between the bottom piece and the top two pieces. The small rectangular piece at the bottom is the backer plate for the tailgate or “South” side of the cross brace. The main top piece with the “prongs” had to be fit around the bed corrugations and was a PITA to fit. The holes you see are NOT bolt holes, but rather match the spot welds so I could see how to align things for drilling the bolt holes. The short angle upright on the left is through bolted with flat head 1/4 20 SS bolts and then VHB’d to the side of the bed underneath for some lateral strengthening.


Here’s the bolted in place result. You’ll see that I added a second top piece. I wanted to rigidify the area over the bed cross brace underneath, which is the strongest support, but I wanted to allow for some flex closer to the front of the bed. My concept was make it a little like a progressive leaf spring. I also chose to use the bed bolt to anchor things further as it’s the strongest connection to the frame.

I made a temporary screw jack with some T-nuts, a hardwood block and threaded rod to push up the bedrail (which the 2x1” 8020 is bolted into as part of my original camper interior build. This was the support for a bench going across the front of the bed). Early on I had used a bottle jack very gently to push up the bed rail just to see how much sag I had and to compress the bulge. It moved enough (maybe an inch or so) that I realized I needed to push the bed rail up and bulge of the interior bed down, but the bottle jack was too big of a foot print. I know the plates look crooked, but that’s just wide angle lens distortion. All the 8020 you see was already there before the bed issues, but others could also push up on the internal Toyota bed rail system.



Unfortunately I was trying to leave town after I finished this and didn’t think to take pics of from the bottom of the bed. Based on the body shop recommendations and a lot of noodling, the bottom piece has a same shape piece of 1/4’ high durometer, HD neoprene through bolted between it and the bed to facilitate the flex. It’s not really squishy at all. Very firm, but will allow a slight bit of movement. In a similar vein, the internal bed top plates are VHB’d to the bed (and each other) with 3M 5952 with really good surface prep. This both bonds the top pieces and allows for some slight cushioning/movement, but barely. All the bolts are 1/4 -20 SS, with SS nylocks and SS washers top and bottom. They are 1 1/4” long, which is too long, but I wasn’t sure how much I could compress things. Turns out it flattened out great. I also used some JB Weld gasket grade auto RTV to seal all the cracks underneath after cleaning off the dirt and the damn Toyota weld sealant, which was the hardest part of this.

Neither I or my engineer friend thought the front of the bed overhang was supported enough so I added some internal struts. Maybe overkill? This more or less mirrors a vertical strut on the P-side that is part of cabinet structure, and hopefully equalizes the side to side rigidity.

The bottom of this is an industrial swivel foot sourced from McMaster-Carr which is rated for a 1000 lb load. I tapped the center hole of the 8020 and epoxied a Weld-nut into it turning it into an HD screw jack that I can tension for both upward support and front of the bed support. It’s very stout. I chose not to try an angled side support to allow for slight movement with the side to side frame flex.

Prior to the fix, I could grab the top edge of my camper and rock it up and down about an inch. I can’t do that now. I could also watch the bed side from my Drivers mirror and the thing definitely moved more than I wanted, especially off camber, including going in and out of my driveway. Now it moves slightly with the frame flex, but it’s the same as the passenger side.

We’ll see how it does over time, but I’m pretty satisfied with it. Hope this is some help to others dealing with this.

 

That’s amazing; great job

 

Thanks. It took a long time, but mostly to sort out the options and go down a couple of blinds paths in cardboard aided design and false starts with choosing the right materials. Once I knew for sure what I wanted to do it didnt take that long for fabrication and install.

 

Davidinphx I direct messaged you about your build!

 

Happy to answer any questions, but you probably should repeat the DM as nothing has shown up in my messages since you posted.

 

Interested in this thread. I was rear ended and having most of my bed replaced. Guess when my truck is ready I should climb under and look at those pinch welds real close….insurance may have some more $$ to dish out. Damn tailgaters….