Engineering And Mechanical Failures Off-Road 

You know your vehicle is having fun when it's toes curl.

There is a fourth way and my favorite way to calculate buckling. Have the DOD pay for material and just simply do destructive analysis. Makes the presentation very easy basically "too long, make it thicker because...this" "ooooh, how much thicke?" "thickerrr.....i can find out exactly how much more down to the gram so you can maximize strength, lower weight, and mathematically significantly lower cost. But that might be about 2 years of R&D with a 10mil budget....faster with more money...with what we currently know"

I’ve gone through an evolution with my off-road damage response. It started with “oh fuck oh god I’m so fucked, this tire is fucked, my spare is inadequate, I don’t have the proper tools” but eventually developed to “ok, so my tires are perpendicular, I’m gonna have to hitch to town to get parts, this is gonna suck, but the victory beer I drink after getting this fixed will be the best I ever tasted”

great story and lessons learned as always. that thin section definitely appears to be an engineered "failure" point to protect the rack to me , why else would Toyota spec out the time and cost to turn that section down with the lathe? Someone smarter than me probably knows.

I used to offroad in a jeep cherokee 2001. That thing had limped off the trail flooded, oil/coolant spewing out, on a donut, in FWD with the rear taken apart. The best part was you could goto pull a part a get basically OEM spares of anything out of the street queen 2wd cherokees. Plus it was a very light car with all kinds of upgrades you could literally pull out of other cars.

I've had the same issue with buying parts off of Amazon - guessing you got a "return" where someone subbed a cheaper part for the return. I found RockAuto to be good for actually getting the right part. But they are slightly more expensive and don't have free shipping last time I checked.

This channel is the perfect amount of geeky, no shouty hyper youtuber personality, and features little snippets of great music. Easy sub 👌

Love the video! Hope to see you do the Land Cruiser 200 steering rack swap. Although you probably don’t want to add more to your list…

Super cool to see how you are able to apply your understanding of engineering to real world problems. Keep it up 👍👍👍

What about making a tierod out if a two-way suspension rod? Automatic fuses are better than replaceble ones, but automatic overload protection is even better. I call it the Thomrod.

That’s one of those parts where close enough is good enough due the variability of off-road terrain. Just make sure the weakest link is the easiest to replace. I’m looking at you, gsxr cam chain tensioner.

Great video man! Pronghorn is a fun hill. Stay safe out there. Hope to see ya out on the trails one dsy

Thumbnail gives me "When you need a oil change but you are shy " Vibes

Maybe you can retrofit tie rods from a tundra they are huge. Also I will be referring to your early microsquirt videos, I installed a honda L15 (out of a fit) into a wildcat 1000 4 seat utv and purchased the microsquirt ecu to manage it, thanks for the videos.

Nice video presentesion i agree with you that thus is an expensive hobby... Hello from Off Road Adventures Greece 🇬🇷

Did you go a whole video without plugging SendCutSend? Inconceivable!

If you don't want to not learn with this, there is a simple way: carry two spare tie-rod ends when off-roading. Treat it as the fuse it is.

is it worth carrying a tierod or two in future trips? i think the hypothesis of it purposefully being the weakest link is strong, and also i feel like a very toyota thing to do.

Glad you survived. We need as many of us named Matt in the world as possible :-D

"F*ck off, I'm full" - thanks for the 😂 reference

Was laughing most of the video, you crack me up! Stay safe Matt 😎👍💪✌️

Yeah those steering rack replacements are a turd. The workaround i found was lock the rack to one end, the shortened end of the tie rod will just clear the frame. Lock it to the other end and it'll clear the other side. Alignment's a bit of a hassle, but it beats pulling the engine.

This is the best superfast matt video in quite some time, and I appreciate you for creating this content for me to consume for free. Thanks, Matt

I just loveee your videos! Amazing, and I am glad you didnt die, good job 👍🏼

What a fun coincidence my professors just had a lecture on buckling last week lol.

Always have spare suspension and steering parts. I switched out my old tie rods and kept them.... 1st trip out the new one broke 😂

The Yak must always be shaved. There is no avoiding it.

"If I could stick a knife in my heart Suicide right on stage" I don’t REEEAAllly want to see you 'Death by Misadventure', but if "Suicide Because I Ignored the Math" is on the table... I WILL appreciate the self inflicted irony.

The stronger the rig, the further it goes before it fails.

Great stuff. Love it. Congrats on not dying too.😂😂😂

What's the bolt pattern on the jaguar, it needs better wheels . Something that fits the body lines .

I'm stripping the paint off my jeep hood today, previous owner left it under a tree and its got more sap on it than a Lifetime movie special.

Absolutely need a spare tire rod now.

I Love your Channel!

MORE 4RUNNER CONTENT Also congrats on not dying

Good stuff and a really good video, thanks for sharing 👍.

8:01 Here , observant viewers will note the shadow of a vulture that is really on the ball. The early vulture gets the 4wd idiot

I just see future Matt shaking his head!!!!!!!

"New 4Runner" zone lmaoooo

The raptor shadow is way cool

New 007 Movie ! TO DIE ANOTHER DAY dun dan dannah !

Upvoted for the diving mask 🙂

The Actual truth of project cars that are used as a daily too..

Congratulations on passing the tilt test... Again.

The car “👉👈”

As always : seriously very funny :)

A lighter car would be reducing the mechanical molasses - right ? The size of cars that you guys take off-road seems err huge ?!

Now you have a spare inner and outer tie rod to bring along

All hail the algorithm!

Toyotas having weak drivelines is something every nissan owner knows

Y'all didn't have a single rope or winch that could have kept your truck upright?

I wonder if your former boss got his money's worth out of the work you did.

Real engineers always use lookups.

Would a car with a live front axle survive this?

Love the 4x4 vids; It's only fun if you break something! Your vids shit all over all over what is offered in the trending section to more traditional local knuckle heads here lol

Next time, put your biggest "friend" on the hood to add some counterweight.

"Engineering didnt answer any questions. It helped in no way. And I have learned nothing. But I didn't die..." greatest quote of all time.

I was designing an extremely long hydraulic cylinder and I found out there's at least three buckling equations, the johnson, cosine and eulers with eulers being the only one they teach in school. Each equation is suitable for a particular slenderness ratio and investigating each one can save you from an overly optimistic result

I work in the rack and pinion rebuilding business , they put those necked down sections as a "fuse" to control what fails.

When I almost broke my neck in 2nd grade, the whole class made "get well soon" cards for me, and one has stuck with me through the years. It said, "Dear A.J. Please Don't Die". So this is my message to you... Dear Matt, Please Don't Die.

Catastrophic Buckling was the first, and hardest, graduate course I took and our book was last published in the 1930s I'm pretty sure because no PhD ever wanted to dedicate their lives to such a difficult subject ever again. Because the tie rod end doesn't apply a load at the exact center of the tie rod axis it decreases the force needed to buckle significantly (there are some kind of maths on this) since it induces a small bending load.

“There it is!” That was genuinely funny. Glad you didn’t die. We would all be very sad.

Even though I'm not an engineer of any measure, it feels like you might be way too comfortable with the phrase "it's probably fine" than you should be as an engineer.

That 45 degree angle was tough to watch. I could have sworn it was going to roll over

I hope you ordered a spare tie rod or two. If you intend a part to act as a fuse then you should carry a spare fuse.

@8:00, vultures instinctively begin circling in.

I agree with your strategy of using the tie rods as your steering fuse. I've replaced a few sets over the years and it's for sure easier than replacing the steering rack. How do I know? I was the one that wrote that steering rack replacement article you referenced. It's not a fun job. I always carry a spare inner and outer tie rod with me when I'm heading onto the trail. Swapping them out is super easy trail side.

The mechanical fuse concept often gets lost in the mission of making a machine tougher, but I am a big fan of making sure the weakest part is either easy to replace or cheaper than the other links in the chain. An old example was PTO winches with bronze sher pins in the drive. From factory they would have a spare pin for when it failed, that would get used and owners would get the shots with replacing them when they abused the winch, so it wasn't uncommon for owners to put in hardened pins. Not a good long-term idea.

I appreciate that you didn't stiffen the control arm. Keeping the failure point there instead of pushing it further up the chain is certainly much easier. Unless of course you're planning on doing more and more aggressive 4x4 trails, but it doesn't seem like that's the case. One thing to note is with the heading back down part and getting fairly, uh, tippy.... If you HAD started to roll, the human reflex to hit the brakes is the WORST thing to do, so instead try to just "let it go". Or even better, hit the gas hard while you're in reverse. That should keep you from rolling in the end, although it would make it a harder landing too... I'm not sure what frame of mind you were in at that point, but it's worth considering for future reference if you weren't already aware of that.

Please don't die. Its kinda hard to find youtubers who make funny engineering content about vehicle slaughter.

All the new Bronco folks out there installing tie rod sleeves are going to start learning about rack replacement soon. I always thought of the TRE as a mechanical fuse and would way rather that bend out on a trail, can hobble it together or replace it right there.

Thumbnail is just the 4Runner saying 😳👉👈

I sent a new viewer to your channel for landspeed streamliner content. Any idea when you'll pick that back up? Hopefully the salt dries out this year.

Back in the day we took tobacco advertising money. I am glad that Soylent green is giving you money.

Matt, you have steel bars on the sides, when the car leaned to the left, someone should be standing on the right side to balance it (ofc it's dangerous, but in europe quite popular in offroading)

This video had everything. It's like distilled essence of Superfast Matt. Ambitious, skillful yet sketchy and the "near enough is good enough" attitude. Amazinf.

It’s often a small oversight in my experience in college of designing things to fail in a specific way. It’s clever of them to have the cheap parts fail as a sacrificial layer to protect the expensive parts, hence the idea of a shear pin. Not only is the tie-rod relatively cheap, but it’s also easy to observe and easy to access should a failure occur. I remember in Mechanical Design class, my professor told us to design a nut and bolt assembly with specific dimensions. It was easy as we can get the factor of safety to like 30+ when under axial load. But then he told us to modify it to where you had to get that factor of safety down to 2.0, and it noticeably got a lot more difficult.

Maths nerd here - I’m not interested in doing the difficult math either, I’ll just trust your method

Order 2 identical tie rods and get 2 different ones in identical boxes... let me guess, Rock Auto? Been there done that!

You should consider doing a thorough check of your steering rack after that bump. The aluminum mounting points on those aren't very fatigue prone, but offroading like you do is a bit outside Toyota engineers design envelope. It would really suck if your steering rack desided to stop being mounted to your frame next time you stressed it.

I'm a new subscriber. I love the engineering prowess, and wicked dry sense of humor you bring to the table. Please keep the videos coming. Thank you.

Screw it, I'll still buy it if you sell

Carry spare CV axles and tie rods, Offroading IFS 101. Keep your old tie rods when you change them out as they can save you in a pinch like this. Takes less than 10min to replace a tie rod on the trail. Also if you can afford it, avoid Moog like the plague.. Get some Sankei 555 stuff or OEM.

Man you need an off-road toy that is not your daily driver... You should build an off-road viper!

Yeah, the 100 series Land Cruiser / LX470 has an 8 inch reverse cut ring and pinion in the front axle; it's a know weak point. (especially if going in reverse, as you wind up running on the coast side of the gear)

At least he has the old (unbent) one to take along as a spare. This will prevent the new ones from ever failing, because the law of spare parts works that way.

Your maintenance intervals on your 4Runner are kinda like my maintenance intervals on my FJ. I'll worry about it whenever it breaks. I carry 4 sets of tie rods because I know if I bend one I'll bend more immediately after.

Replacing the windscreen will cross cleaning it off the list at the same time. Efficiency.

Glad you didn't die and thanks for sharing your stories. Have fun, be safe, stay dangerous :-) PS - did you keep the old tie rod for just in case? Also the title should end with "So Far" as you are putting together an off road Viper LOL

you know its gonna be bad when matt uploads a video named "sketchy...."

Hey two steps forward and one step backwards is still three steps as far as the fitness tracker cares.

Looks like the tie rod is the same for both sides. If it's a fuse in the system, carry a spare. I carry spare U joints in my Old Bronco. Same deal.

Proper off-road mechanical fuse replacement procedure: 1. Identify the mechanical fuse through properly neglecting the spotter and finding a rock the hard way (as Matt did.) 2. Use a very sketchy method to return the vehicle to 90% of safe operation at the trail head. Possible methods include: ratchet straps, welding using jumper cables, two batteries and 10 year old muddy welding rods, nearby forest lumber, etc. 3. Buy and replace both right and left fuses despite only breaking one. 4. Throw old un-blown fuse into spare parts box in the back of the off-road vehicle 5. Go find new ways to come close to soiling your underwear off-road, knowing you're fully prepared in case of another blown fuse!

Too many of us are living vicariously thru your questionable decisions. Therefore we, forbid you death or any significant injury that stops you from posting your projects. Keep drinking that healthy green stuff, as we watch your vids drinking beer...

I wonder if it's possible to make the tie rod weaker but also self repairable, i.e. with some kind of spring/damper loaded to 7000lbs to stop the impulse and absorb the impact. If you experience these loads in an emergency stop then you are probably dead anyway.

If I learned anything in my decades of Toyota 4x ownership it’s: buy OEM parts! The important ones anyway. Never install reman or aftermarket, particularly steering rack and related items.

I just came back from a fun weekend. One buddy cracked the frame on his pathfinder, I smashed my skid plate into my t case oil pan into the gears inside, and buddy #2 tried an obstacle, blew up one CV in his pathfinder, figured it’s already broken tried again and grenaded the other side. Then packing camp anti-theft tried to lock him out. All around a good time and many obstacles were conquered. Now time for “maintenance”

Pro tip: Carry a few extra tie rods (inner and outer) in your 4runner, you can get them brand new online for less than $10. Literally everybody does that...I even have 2 in my 4runner for this reason. The tie rod was specifically designed to fail by Toyota in that exact circumstance and be easily replaced on the trail with minimal tools by one person in under 20 minutes.

I studied granular buckling, for which we have no equations. Just DEM and fingers crossed. :(

Every windshield failure I have had was from hauling lumber. $60 in free wood has cost nearly $1200 in windshields.