Increase towing capacity by upgrading rear suspension and brakes?

Beefier springs can help with rear end squat. But won't help with payload at all.

 

Supercharger and rear suspension you can tow that. But then if you get in an accident the insurance adjuster looks at the trailers weight and could find you 100% liable. Ive towed lots of different weights and up to 5k is barely noticeable, 7.5k you notice but not a big deal, 10k you are more white knuckling due to brakes/sway/etc, more than that you can definitely do just gets exponentially unfun at highway speeds. Whereas a 1 ton truck is 2000lbs higher curb weight and 700+ torque with brake’s to stop it. “Ultralight” 24ft travel trailers are where it’s at for Tundras for peak enjoyment. I do appreciate a dedicated RVs bathroom to be able to use while moving, I call it the “spousal approval unit”.

 

I hope you know it’s more than just tire, axle, payload, and other ratings. It’s also the actual design of the vehicle when it comes to the frame, body mounts, suspension mounts, etc. There are actual material/structural design considerations amongst other parameters that form the foundation of where these rating numbers are derived from.
I’ll give you a real world example, that I witnessed first hand when a vehicle payload was arbitrarily increased without due design and test considerations. I was involved with the purchase of militarized Mercedes-Benz G-Wagons for the Canadian Army back in the early 2000s. I was one of the systems engineers working on the project on the government/military side. The specifications called for a payload capacity of 1,500 kgs (3,300 lbs). This was a massive increase over the stk rating of the commercial G-Wagon. This payload requirement was due in part to the vehicle being able to be up armoured with ballistic glass and plate. Mercedes said no problem. Well, it turned out to be a massive problem. They did perform some changes to the vehicle in anticipation of the much heavier payload requirements like adding a middle member to the boxed steel frame, heavier springs, heavier shocks, stronger axles, and a second stamping(s) to the floor. As part of the contract requirements we performed an exhaustive Reliability, Availability, Maintainability, and Dependability (RAMD) as well as vehicle performance trials down at the USA Military’s Aberdeen Proving Grounds. This took almost two years to complete. In those two years of brutal on the road testing which included gravel, secondary, and off-road courses, the test vehicles experienced a myriad of failures due to the excessive weight. Vehicles were weighted down to simulate “combat load” or maximum payload including installation of the armour kit. Part of the trials also included towing a small trailer loaded to 850 kg (1,870 lbs).
Failures included broken front axle panhard brackets, failed trailer pintle bracket, and cracked body/ body mounts. In total, there were over 150 design changes made to vehicle as a result of the testing we did.
So, what I’m saying is one should not think that they can simply change a few things, and expect to exceed the manufacturers ratings without possible serious consequences. Nowadays, with modern CAD and modelling software, manufactures rarely “over design” items like they used too in the days before CAD. As an example of how sophisticated modelling is (at least back then), to address the issue of body/body mount cracks, Mercedes had to redesign the firewall, front body mounts, and the C and D pillar reinforcements. To do so, they took empirical data gathered from testing, and ran computer simulations to model the loads experienced on the vehicle with the new design. They used a super computer to do so, and it took a solid two months to run the simulation. The simulation was successful, and changes were made to the vehicles that were both already manufactured (i.e. they had to be retrofitted = $$$), and those still yet to be produced.
Hope this sheds some light on what goes on behind the scenes when it comes to vehicle design and vehicle ratings.

 

This camper you speak of is way too small to accommodate your enormous balls!

 

No

 

Brakes, axles, frame, entire suspension system including shocks and leaf springs, possibly wheels and tires, no one even knows what else because none of us were involved in designing the Tundra and thus don't know what all goes into the GVWR and GCWR of the truck. And none of that will officially or legally increase your capacities. At that point, just buy a 3500 and be done with it.

 

I'll chime in here because I don't think anyone has mentioned this yet, but the Tundra doesn't weigh enough to handle that kind of weight. Even with upgraded brakes/springs/bags or whatever that load will absolutely push you around on the road. I tow daily with my tundra for work and have definitely pushed the limits of its towing capacities.....not fun at all. Not to mention with a trailer that large and heavy I would hate to be towing that dude in a 40mph cross wind, that trailer will have you all over the road. Not sure on what kind of savings you're getting with the trailer, but minimum you'd need to upgrade everything you mentioned plus regear to 5.29 and at that point I can't imagine you'd be saving any money. I'd just fix the broken spring on your truck and look for a lighter trailer if it was me. Good luck

 

While I agree that he should not pull a 13k+ 5th wheel with ANY Tundra, this insurance claim denial idea is 100% false.

Insurance exists to protect people against their negligence. Even if you cause an accident knowingly doing something wrong or illegal (speeding, texting, driving while intoxicated, pulling too big a load, etc), they will pay the claim. Insurance MUST pay for claims UNLESS they can prove you caused an accident on purpose in order to collect insurance money. That would be insurance fraud, and they don't have to pay when it comes to insurance fraud.

Now, will you get dropped after the fact, or will your premiums go way up? Yes, those are possibilities.

Remember the guy with the Ram 3500 who overloaded his truck with a gigantic truck camper which broke his frame? It was insured, and his insurance paid for it.

 

I agree, however I believe that in the event that damages exceed the insurance coverage, civil litigation becomes the next step.

 

I forgot to mention, welcome to the site Valhalla!

Don't let the bad news run you off, it's a pretty great resource.

 

Changes to suspension can increase load handling ability. Changes to gearing can improve getting power to the ground. Changes to brakes can improve braking.

Can you haul that beast of a trailer with your Tundra? Absolutely.

Is it a good idea? Probably not... Is it legal? Probably not... No matter how many mods you make to the vehicle the sticker on the door states the limits as set by the manufacturer, now those limits are pretty damn arbitrary and Toyota is much more conservative than the other manufacturers but if you exceed what's on that sticker it could get you jammed up if something happened.

At one point I had a 14k bumper pull toyhauler with a WDH cranked tight that I relocated a couple of times short distances using a 2003 Chevy 2500HD extended cab long bed. I was over limit and it was a bad idea, and handled like it was a bad idea. Towing at a trucks posted limit is a legal thing, but most are in truth BADLY over loaded when at the limit the manufacturer has set IMHO.

 

Everything I came across on the net suggests your policy could be void if you overload your vehicle. If you knowingly overload your vehicle, it would not be considered negligence. In any case, as others have suggested you could be facing both criminal and civil litigation as well for causing an accident while driving an overloaded vehicle because of violating the law.
Suggest if the OP is still seriously considering going ahead, they should contact their insurance company to see what their policy specifically says.

https://www.continentaltoyota.com/b...ce/overloading-your-vehicle-can-be-dangerous/

https://www.kbb.com/car-advice/towing-capacity-guide/

https://www.wagnerlaw.com/overloaded-cars-trucks-dangers-put/

 

Something tells me OP is long gone.

Didn't get the answers he wanted here, so probably went elsewhere.

There's a Tundra and Trailers FB page where I see people posting and boasting about some ridiculously large trailers behind their Tundras, maybe they'd be more forthcoming with the answer which he seeks.

 

First link is a dealership, which is nowhere near an actual authority on insurance law.
Second link says you can increase towing capacity by having an RV shop install new axles in your tow vehicle.
Third link is lawyer speak.

If overloading is illegal and insurance companies can get out of paying, why did this guy's insurance fix his truck? It is clearly broken due to being overloaded:
https://www.truckcamperadventure.co...-pavels-overloaded-and-broken-ram-3500-frame/

Insurance exists to pay for your illegal and negligent acts. Why does insurance cover DUI accidents or every other situation where a driver knowingly broke the law (driving 85 in a 55, for example)? Insurance pays up to your policy's coverage limits. But if you caused more damage than your policy covers, good luck!

 

I have the ironman 4x4 overland springs and am very happy with them. these trucks handle heavy loads really well and shouldn't be an issue. the wind resistance is the real issue. keep it 70 or below and that will help. frame and suspension will handle it no problem.

 

Yeah, I think OP is gone…

IMHO, I’ve done about as much as I can to make my truck a better tow pig, short of a blower.

Good leaf packs from a reputable manufacturer, like Deaver or Alcan.
Huge brakes from Alcon.
ADS shocks
5.29 gearing with a LSD rear.
Engine tuning on dyno and trans tuning that works well with my towing.
LRE tires on the truck and trailer.
WDH set up with measurements and scale.


What I’m doing wrong?
35” tires…. Those aren’t killing me, but certainly don’t help.
My truck is heavy. I am absolutely over GVW when I tow. Doesn’t feel like it, but facts are facts.


I wouldn’t dream of towing a trailer like OP described. That’s just stupid. You can’t make a Tundra into a wan-tawn.

 

No, No and No
Always the same discussion over and over, geez!
1 - GCWR, GAWR, TW and PAYLOAD will never change whatever you do or change in your truck.
2 - DOT and Insurance don't care about your upgrades , they'll go by the sticker!

My 2 cents:
17,000 miles towing my travel trailer in 2023
- Dry 4200, max 6000lbs, 60% of TWR which is recommended rule of thumb for 1/2 ton truck
- 25ft long, trailer length under 28ft recommended rule of thumb for 1/2 ton truck, those who have experienced strong gusts of wind know what I'm talking about.

 

Almost true! You can decrease your vehicle weight and increase your payload that way. Ditch the spare tire. Take the rear seats out. Get a lithium battery. Get rid of the bed and put a lightweight aluminum flatbed on. All these things that decrease vehicle weight make more room between curb weight and GVWR which equals higher payload.

 

Here’s a letter from an Utah state trooper with state law cited. Thought it was relevant to this discussion. It would be nice if we could get all 50 states’ regulations in one place.

 

I wouldn’t put much faith in that letter from a state trooper about the legalities of exceeding the vehicles’ GVWR. In his opening statement he makes reference to the manufacturer’s GVWR as it relates to the maximum weight a vehicle can operate SAFELY. Lol! All the traffic laws are all about operating a vehicle SAFELY. What a backwards statement.

As an example, many years ago, a co-worker told a story of how her and her husband were towing a large 5th wheel travel trailer though the desert in the US mid-west. She was driving and passing an 18-wheeler coming down a slight grade. There was a cross-wind, and as soon as her pickup (F250) and the trailer cleared the semi-truck, she felt the trailer get “sucked” in by the air vortex between the semi-truck and trailer. She ultimately lost control and flipped both her F250 and trailer into the median. She and her husband were very lucky, and only sustained minor injuries, and fortunately only their vehicle was involved in the accident. So, due to some unusual but common set of circumstances, we had the tail wagging the dog. Did she break any laws? I do not know the specifics, but they went out and got another pick-up and trailer from the insurance.

 

Buzzkill







JK. Great post.

 

Umm, ok…He’s saying that the state of Utah does not base legality of a load on the manufacturer’s recommended GVWR limits. “No crime is committed when a vehicle is operated in excess of its GVWR.” Rather, when one is in excess of axle, tire, and/or wheel limits—that’s when the state of Utah says there’s a problem. It’s really not that hard to understand, and at no point does he contradict himself.

 

We have regulations, laws, etc. to ensure our safety and the safety of others. Vehicle manufacturers establish GVWR with road safety in mind, and identify such on each and every vehicle IAW FMVSS regulations. Saying it is not a crime in the state of Utah to exceed the manufacturers stated GVWR in accordance with FMVSS regulations is an oxymoron. Why then even go to the trouble of identifying the GVWR on each and every vehicle sold on the USA in the first place IAW FMVSS if exceeding it is of no criminal consequence?

 

It’s not an oxymoron because the door jamb number is not a legal standard recognized by the state of Utah (or any other state that I’m aware of) such that they would write a law criminalizing the exceeding of it. Is there a federal statute that criminalizes exceeding those numbers? Pretty sure nope. Those numbers appear first and foremost to be a CYA for the manufacturer. Better safe than sorry in our highly litigious society.

I’m not sure why this is surprising. Maybe you live in a different country, but in the US recreational towing by private vehicles is hardly regulated at all. RV dealers sell people way too much trailer for their truck all the time. Overland outfitters often bolt way too much crap to someone’s overland build that puts their truck overweight before anyone even gets in it. There are builds on this forum that exceed GVWR by 1800lb + with no one in the truck.

In countries where this world actually is highly regulated like Australia for example, you can put heavier springs and skids on your 200 series Land Cruiser and get a certified GVWR upgrade to 9200+ lb. I’ve looked at the pages where outfitters offer this govt certified upgrade; it doesn’t look like they consult Toyota engineers at all before certifying those rigs for an extra TON of weight.

 

Trailer tongue weight also counts against GVWR.

 

So, let me ask a question…

Four years ago, I had a new PJ flatbed trailer built to my specifications. It’s got (2) 5,200# axles and 235/80-16 tires that have a load capacity of 3,520# per. Worth noting, I always bump my trailer tires up a range or two so I’m never riding on the edge of tire capacity.

At dealer request via the customer, PJ will derate the trailer listed GVW to 8,000# to reduce registration costs. I won’t say which way I went.

How much can my trailer safely weigh?

 

We are talking in circles. The GVWR/FMVSS sticker is a federal requirement. No vehicle in the USA/Canada can be sold without the vehicle being certified by FMVSS/CMVSS and having such sticker affixed to the vehicle. It is not a CYA dreamed up by the manufacturer. In one of my previous posts, I linked to several sources indicating liability from being over one’s GVWR.
What we’re both saying, but in different ways, is that even though Utah state law might not make it a “criminal” offence to load a vehicle beyond it’s FMVSS compliant GVWR, it is nonetheless unsafe to do so, and one could still be held civilly liable for doing so in a court of law.
Getting into RVs is a whole other matter, as the regulations/laws are lax to say the least, because an entire industry would be wiped out if they “cleaned” up the driver requirements to drive such beasts as well as the shoddy design/manufacturing standards. This is a clear example of $$$ before safety.
Being a Land Cruiser owner and a fan of Aussie off-roading, I’m somewhat familiar with the regulations down under. First of all, as you suggest, they have very strict laws regarding what can be done to vehicles for off-roading/expedition purposes. Obviously anything done to increase the vehicle manufacturer’s GVWR would automatically void the vehicle’s warranty. As you suggest, they have outfitters who are government/state certified to increase the vehicles GVWR, but only they are legally permitted to alter the vehicle to increase its’ GVWR which often includes stretching the frame to accommodate the “tray” systems they use exclusively there. Actual engineers perform the inspection and certification process. How the government/state determines what modifications are safe, and the method in which they are carried out, I have no idea, but like I posted about my experience with Mercedes and their militarized G-Wagon, one cannot just simply say the vehicle can carry an extra ton of weight with bigger springs and tires. If my G-Wagon example hasn’t convinced you, I don’t know what would.
Here in NA, or at least in the USA, from what I’ve seen on TV, it seems almost anything goes went it comes to home built/modded vehicles. Does it make it right or safe? Likely not, but here in Quebec where I live, they actually have fairly strict laws for “off-roading” modifications and any other vehicle mods. Do I see lots of vehicles modded in a way that breaks those laws - yes. Do the cops bother them - not for the most part. If you get into an accident with an illegally modded vehicle, will the insurance company void your policy - yes. In fact, it is very difficulty to even get a kit car certified here in Quebec.
All this is now way way off-topic. The point being is that by exceeding the vehicles various weight and payload ratings your are making it unsafe for yourself and others on the road. Hope you can at least agree on that point.