Cab mount chop ..

Can you do a cab mount chop without welding in a cover plate ???any reason you need to weld in the cover piece ??? Or can you just run it without???

 

Why not weld the plate in? Stronger and cleaner.

 

Def will he stronger and perfect the cab mount itself. I have seen folks run without for some time and weld later. Will it work yes but I would say good to add one later unless you replace with poly bushings etc.

 

There’s also the large hole into the frame at the mount. If left exposed it’s a great entrance for all sorts of crap into a frame that wants to rust from the inside out at the drop of a hat. If you live somewhere that gets road salt it’s certainly a concern.

 

Exactly the first 2 posts and I'll add that it looks like shit without.

 

It collects debris and grime, the bushing inside will rot and wear faster.

I would never run one open for longer than a month.

 

I got a new frame in 2019 and had to cut cab mount to put my tires on. Didnt weld anything back on. Have i had issues since? No. Does it look bad? Probably, but its not a show truck. Does welding a plate in reinforce anything? Questionable according to me (random guy on the internet)..

 

I don't own a welder or know much about welding ...if I could just cut it out would be diy and cheap ..so I wanted to here from others on the subject

 

Thanks this the type of insight I hoping to gain . Thanks for your input

 

The cab mounts are what keeps your wheel and also whatever you hit/hits you from smashing through the wheel well and into the cab (and your legs) in a frontal or quartering collision.

Chopping them absolutely affects crash safety. Welding in a plate restores an unknown but nonzero and nontrivial amount of the impact-worthiness sacrificed by chopping. How much exactly? I don't know, but consider 1) how close to the line Toyota rides on design and spec to keep costs down, and 2) how much by simple mass of the cab mount you remove when chopping, and that the reduction in impact resistance is likely higher than that due to the loss of geometry. In other words, you're dropping (let's say) 20% of the mass of the mount, but because you're losing an entire face of the structure, you're losing far more than 20% of the strength (stiffness, resistance to deformation) of the structure.

If you're doing a CMC to fit wheels and tires that already cost a fortune, don't cheap out on a couple hundred bucks on a one-time purchase to buy a CMC plate kit and have a decent welder put them in.

 

Thanks for your input I am also considering a cab relocation as well ..just want to hear what other 's in the tacoma community thoughts are

 

Weld it up IMO.

You're effectively removing a significant portion of the load bearing structure of the mount if you leave it empty. The stress in the mount will likely be an order of magnitude higher (i.e., 10X) with a non-capped CMC, compared to the stock mount as you're removing one of the major members of structure. Instead of having 2 members primarily in bending (top and bottom plates) and two members primarily in shear (front and back side plates) (under normal, static loading conditions), we now only have one member primarily in shear. And with expected loading conditions, this asymmetric structure will also induce twist—so instead of having 2 members primarily in bending and 2 primarily in shear, the remaining 3 members now also have to resist torsion as well, which drastically reduces the overall strength of the structure.

Is the material/structure still within the safety margin Toyota built these trucks to? Probably, these trucks are pretty stout. Is it creating far more stress in the material/structure without it capped? Absolutely. And even if it does stand up to static loading (if we pretend vibration and dynamic loading are not an issue), fatigue is also a concern. Will it survive 10^2 load cycles? 10^3? 10^4? 10^5? Without testing we don't know exactly, but we can say that the structure is far more susceptible to fatigue than it was before.

As @deanosaurus mentioned, if you need the CMC, you're likely already spending a bunch of $$$ for whatever you're trying to fit in there. Spend the extra few hundred to get someone to weld a plate in and do it right, in my opinion.

 

Thank you for your input I appreciate it.. I am only fitting 33"'s...I am getting rubb when going downhill stuffed in a turn after adding a wedge camper . I also have
135lb..bumper
70lb winch
67lb agm battery
15 lb compressor
Added weight/force from cab over wedge camper

Do I have money for raco bell NO but I do have ...

 

Just buy the relocate kit and do it right the first time.

 

That large hole is gonna be there anyway (I plugged mine with a custom plastic plug) and the cab mount is gonna be open at the bottom anyway, where most of the tire roost will come from… not much is gained in term of keeping crud out by welding it back up.

that said, there’s really no need to buy/cut up a new plate. You can cut out a slice of the mount instead, bang it over with a hammer, and then stitch weld it. Achieves the same, and is cheaper. Still requires welding tho

 

Wide open versus semi shielded makes a difference is all I’m saying. I’ve traditionally plugged mine as well. OP can just yank the body mount cover from under the carpet and plug the hole if cheap is what they are after. No need for a custom plug.

 

Just get some big tubes of JB weld and smear it in. Just as good as welding it.