Bed stiffeners...yay or nay??

Sheet of steel here, got it

 

Hahahaha! Yup!


Or, good old Dukes of Hazzard.

 

A lot of this is the same issue with cowl shake on convertibles. The remedy is higher door sills, floor panel stiffening, or other methods.

Similarly, there is some mystery surrounding the low towing capacity of our Subaru Forester. Other markets, it is 2,000kg (4,400lb). Here, it is 1,500lb. One theory was tongue weights are higher here for similar GWs. The other theory is that the body is strategically stiffened in other markets.

Fun stuff!

 

NERDS Hahahah!

 

I love my AP bed stiffeners for peace of mind and extra tie down area

 

Thanks.

I would argue that the mass of the bedsides is negligible in my example above, as that is a fixed/set mass that the truck was originally designed around. Toyota's engineers are certainly familiar with the static to dynamic translation of forces I discussed above and would design around that. Though I do not doubt that you felt a difference after installing the stiffeners in your truck, I just don't think the factory included weight of the bedsides would ever present an issue that a stiffener would be needed for. Adding a bunch of weight to the bedsides with an RTT? You bet you need a stiffener.

I don't agree with your rationale for the undercut in the steel at the corner of the bed frame. A circular shape or transition between discontinuities (this is the shape that it looks like to me on my truck) is the shape that offers the lowest k value, as the k value is determined by the ratio of a and b (i.e. the length of the crack and the width of the crack). This is why people who have cracking dashes (very popular in the E30 world that I come from) are told to drill small holes at the ends of the crack to mitigate or completely stop crack propagation. This is because you take the worst case (a very thin and long crack) to the best case (a perfect circle) by manipulating the ratio of a and b from a very small number to unity. So Toyota's use of that undercut in their design gets a big thumbs up from me as it is the most intelligent solution that is easily incorporated into the truck.

^^ I reread your initial comment that spurred my comment above and agree with you. While that undercut is the best shape to use, I do agree that it can't be counted on to resist the added lateral forces caused by a RTT. My apologies about my confusion, but I figured I'd leave what I typed for educational purposes.

I agree with your last point based on my initial post above. Increase the distance and you are better off. Resolve moment forces into pure tension and shear and you are always better off.

Also, you are correct about the cross bracing aspect of attempting to reduce lateral forces in your sketch above. You must transfer the force from a distance above the neutral/resolving plane and place it co-linear with that plane to remove any moment forces. Monkeyevil incorrectly remedied the problem above in his image, unless of course his red line is meant to be a 'fixed' beam/tie (i.e. it can resolve moment forces at its ends) though this opens up another new set of forces to deal with and faces the distance aspect that I brought up before.

 

Some good anecdotal evidence in this thread that bed stiffeners are worth it

https://www.tacomaworld.com/threads/should-i-get-bed-stiffeners.633366/

 

You're welcome!

I agree with this but there is some discussion of cracking / spreading from heavy wheeling on unloaded beds. Like you said though, that is well outside of what Toyota would have designed for.

But, that is the location where the failures appear. Yes, a large undercut radius is stress relief, but it appears insufficient based on failures. IMHO, the design would require heavier gauge, a revised detail design, or other solution.

There is some discussion around drill stopping cracks. It certainly reduces the k value, but stop drilling has to be done carefully to no initiate another crack.

It has been a long time since that info was fresh though.



Good discussion.

 

I was merely talking about a somewhat non-obtrusive solution that stops this <----> from happening to the bedsides. Assuming the structure of the rack itself allows the legs to splay out under load. But as you stated correctly, that won't help for the rack going like this /.... /

Obviously I'm not an engineer, nor do I design products, we hire professionals for that

Edit: actually I take that back, I designed this highly stressed mount
https://www.victory4x4.com/product/VT3CB-BARE.html

 

Yeah, I modified my post above to italics after I re-read your post. My bad about my confusion. I agree with you that it is definitely insufficient for this truck use that Toyota did not design around.

Bed stiffeners are certainly much easier to use to remedy the problem than attempting to fix that undercut.

Cheers!

 

Ah yes, that tie will definitely do that. Though the much more detrimental effect is the /..../ followed by \....\ you noted above. This gets us into cyclic loading (oscillating, repeated, tension and compression of a specific amplitude and period) and S-N curves, which is a whole other bag of goodies.

If you ever need a second professional opinion let me know!

 

Some pros are questionable.

 

It is ALL good!

Above all, it is a problem with an easy and useful fix.

I got the stiffeners because of future plans that didn't pan out and just taking a look at the area in question. The potential problem was obvious, but like you noted initially, it is debated quite a lot.

 

I would like to add that i have seen a picture of a 3rd gen with bed stiffeners that cracked right above the stiffener on the inner bedside.

I think ATJ or rago...maybe ATH i cant remember makes front corner reinforcements too which i have been eying. I tend to toss the truck around and i dont want the shell or the bed to get messed up

 

Not to side track you're question but to add to your thinking look for some posts about the passenger side front bed bolt needing a spacer between the bed and the frame.

 

And, in the link that you posted, that crack in the upper part of the stanchion is pretty shocking.

Not raining on the parade, but some questions would be great for any failure. Stock or stiffened. Driving style, bed use, etc. Also, no material or installation is perfect. There could have been a flaw in that Taco or the installation? Just lots of variables that would be great to gather up.

 

Is this from wear over time or just leveling the bed? Of course, we have seen the Taco Lean, cab, bed, and bumper alignment fun.

There was some posts in the 2nd Gen forum about bed sleeve wear. I haven't seen much here?

 

Unfortunately, like most things, it is debated most ludicrously (through stories or by what they 'think' is going on) by those who do not know what they are talking about and more directly (i.e. a fully technical response without anecdote) by those who do.

 

Very true!

Thanks for that good post that will hopefully help folks down the road.