New motor - New towing capacity

[Big Miker C]

I just had a 6.7 installed in my 2004 4x4 Crewcab short bed. Also installed larger pump, injectors and turbo. How can I determine what my towing capacity will be? I'd like to tow a 5th wheel toy hauler.

 

[dhay13]

What was the factory tow capacity on it? That is still your legal tow capacity. Can't change it. It may be more capable of towing but it is still whatever it was from the factory

 

[2003F350]

What was the factory tow capacity on it? That is still your legal tow capacity. Can't change it. It may be more capable of towing but it is still whatever it was from the factory

This. You can't change your factory tow capacity, UNLESS you have it DOT inspected and certified to tow more. I would NOT go that route unless you also want to risk having to pay for commercial insurance, which is vastly more expensive.

No upgrade you can possibly do to your truck will increase its legal payload or towing capacity. It will only make it pull that legal amount better.

That said, there are VERY few 5th wheel toy haulers I would consider putting behind something that is NOT a dually. They are usually EXTREMELY heavy on the pin - my old 41' Cyclone had almost 3k for pin weight, and my FIL's 42' Spartan is in the same ballpark, when not loaded. There are some that are lighter and much shorter with smaller garages that you could consider, but not many.

 

[tron67j]

If your former engine was lighter, subtract the difference from door sticker, your payload has been decreased.

 

[dhay13]

Typically your towing is restricted by suspension and brakes, not power so either way you haven't changed your limits. And yes, you should weigh the truck now because if it weighs 200lbs more then you now have 200lbs less payload available

 

[engineering]

What the others have said.

This becomes a legal risk assessment decision on your part. A vehicle modified from the original factory is a target for scrutiny in the event of an accident. Even if the accident is not your fault - it can be made to be after asserting issues with your modifications that negatively impacted a particular performance expectation.

All of that is true if you are still properly loaded. If you load the vehicle outside of the original OEM specifications - you become a legal sitting duck even with what may appear to be a minor incident.

There are so many factors that are interleaved to determine the safe capacity of your vehicle to carry weight or pull a trailer. The frame, brakes, suspension, axles, wheels, transmission, weight distribution, etc, etc......are all complex on their own but even more so when you have to marry all these factors.

If you need more capacity - your only practical option is to get a new truck. There is really no scenario that an individual can re-design and re-characterize a truck in a legal way.

 

[Toddbigboytruck]

What was the factory tow capacity on it? That is still your legal tow capacity. Can't change it. It may be more capable of towing but it is still whatever it was from the factory

I was just speaking with a ministry of transportation officials an you can have any vehicle rating changed if you have done with the correct modifications and have it inspected and certified by a garage that is licensed you preform these inspections. Now that is in Ontario Canada but I was able to find a few articles that it may apply in the States as well. I keep reading on this forum about the sticker is a life or death matter, if you are 1 lbs over you will die and kill everyone within a 3 km radius Well it isn’t true. Also the door jam sticker in Canada or way different then the States. In Canada all ours states the maximum payload not Gvw etc. or any of that

 

[engineering]

I keep reading on this forum about the sticker is a life or death matter, if you are 1 lbs over you will die and kill everyone within a 3 km radius Well it isn’t true.

I think you are not interpreting this correctly. This is really a LEGAL matter and I have not heard anyone even hint that the vehicle will simply fall apart with 1lb over a stickered limit.

The dearest pastime here in the states is not baseball - it is suing people. The point is that going over weight is an easy way to be successfully sued even in a fairly minor accident. In a major accident (even if it is not your fault) you can have harsh legal exposure that can even go beyond your insurance coverage. For all I know, the insurance fine print may limit coverage if the vehicle has been modified.

Of course people take the risk all the time - some out of ignorance and some it is just a calculated move. I am not willing to risk it personally which is why I purchased a trailer that allows me to stay within all the factory stated limits.

I am adding a supercharger and airbags, so I could probably get away with a bigger trailer - but at a risk of legal problems that I don't want.

 

[Toddbigboytruck]

I think you are not interpreting this correctly. This is really a LEGAL matter and I have not heard anyone even hint that the vehicle will simply fall apart with 1lb over a stickered limit.

The dearest pastime here in the states is not baseball - it is suing people. The point is that going over weight is an easy way to be successfully sued even in a fairly minor accident. In a major accident (even if it is not your fault) you can have harsh legal exposure that can even go beyond your insurance coverage. For all I know, the insurance fine print may limit coverage if the vehicle has been modified.

Of course people take the risk all the time - some out of ignorance and some it is just a calculated move. I am not willing to risk it personally which is why I purchased a trailer that allows me to stay within all the factory stated limits.

I am adding a supercharger and airbags, so I could probably get away with a bigger trailer - but at a risk of legal problems that I don't want.

Yes but he swapped the engine for a larger one. So if he was to go to the correct garage he may be able to get a recertifications on payload and tow capability. As for the suing first get facts after we don’t have that in Canada hell some provinces have provincial car insurance coverage this way every one is equal and have insurance

 

[2003F350]

Yes but he swapped the engine for a larger one. So if he was to go to the correct garage he may be able to get a recertifications on payload and tow capability. As for the suing first get facts after we don’t have that in Canada hell some provinces have provincial car insurance coverage this way every one is equal and have insurance

It is likely that, if he went with a larger (and therefore heavier) engine, his payload will likely have gone DOWN, not UP. If he did no other modifications to brakes, suspension, frame, etc., then I can't think of any way that will positively affect his tow capability.

It IS possible to get your truck re-certified for something other than the factory ratings, but by just changing engines, that is highly unlikely.

Think of it this way: If you take a 6.4 Hemi, and throw a roots-type supercharger on it, you will drastically increase the torque and horsepower. However, without doing any other mods, you haven't really altered your payload or tow capability - you are still limited by your stopping power, handling, and axles.

 

[Toddbigboytruck]

I don’t know how you tow but I have the trailer stop for it self. My truck isn’t stopping the trailer

the point I was trying to get across was that the sticker isn’t law for ever and ever it can be recertificated

 

[tron67j]

It is likely that, if he went with a larger (and therefore heavier) engine, his payload will likely have gone DOWN, not UP. If he did no other modifications to brakes, suspension, frame, etc., then I can't think of any way that will positively affect his tow capability.

It IS possible to get your truck re-certified for something other than the factory ratings, but by just changing engines, that is highly unlikely.

Think of it this way: If you take a 6.4 Hemi, and throw a roots-type supercharger on it, you will drastically increase the torque and horsepower. However, without doing any other mods, you haven't really altered your payload or tow capability - you are still limited by your stopping power, handling, and axles.

^ This.

Foe general public, I think it is a safe statement that they will almost always run out of payload before they run out of towing capacity. And, as already stated, adding engine mods or heavier/more powerful engine may increase theoretical towing capability but at the same time will decrease payload capacity.

 

[Loudram]

The OP lives in AZ so only US laws are applicable to this thread. That being said here is a great article talking about this very topic. It's worth a read. It's not long.

https://fifthwheelst.com/altering_vehicle_weight_certification.html

 

[2003F350]

I don’t know how you tow but I have the trailer stop for it self. My truck isn’t stopping the trailer

the point I was trying to get across was that the sticker isn’t law for ever and ever it can be recertificated

Your trailer brakes and truck brakes should be set to be roughly equal, and your truck should be able to stop the entire load IN CASE THE TRAILER BRAKES FAIL, which is likely. You also don't want your trailer brakes dragging you to a stop under normal circumstances, as this leads to increased wear on your trailer brakes (which can cause premature and unexpected failure, putting you into the truck being all you have), as well as causing undesired and often unexpected reactions in your truck during emergency maneuvers.

In other words, if your trailer brakes are slowing you down, you're MORE likely to lose control and be involved in an accident. It's not safe, it's dangerous and could be deadly.

 

[Toddbigboytruck]

The OP lives in AZ so only US laws are applicable to this thread. That being said here is a great article talking about this very topic. It's worth a read. It's not long.

https://fifthwheelst.com/altering_vehicle_weight_certification.html

Thank you that was the point I wanted to say was that the sticker can be Nile and void is probably done so

To the rest yes he change the and that we all he stated he did. My comment was that you can change the rating. That was all. It can be done

 

[engineering]

I can't imagine what it would take to re-certify a vehicle in the USA.

 

[Loudram]

I can't imagine what it would take to re-certify a vehicle in the USA.

That article I posted talks about that. Private owners can't.

 

[Gregg kellogg]

What was the factory tow capacity on it? That is still your legal tow capacity. Can't change it. It may be more capable of towing but it is still whatever it was from the factory

 

[Gregg kellogg]

you can change the tow rating with gear ratio in the rear , if you take 2 identical trucks same engine, trans , one has 3:73 rears and the other 4:10 rears the tow rating will be approximately 3,000 lbs more with 4:10 , i know this for a fact, because i ran into this situation with my truck and 3:73 gears i spent alot of time on phone with ram techs , with 3:73 i could pull 19,000 lbs , and with 4:10 i could pull 22,000 lbs , i put 4:56 gears in it , i pull a 15,000 lbs toyhauler made a huge difference in pulling power , have 6.4 hemi, but if you want to be legal it needs to be recertified

 

[engineering]

..... but if you want to be legal it needs to be recertified

How do you do that in the USA? It seems impossible if you are not a large corporation with a lot of money.