Weight distribution questions

ember1205 · July 4, 2015

I'm aware of the physics, I'm wondering what the legality and capacities of these trucks are... If I only needed a WD hitch because if the stock hitch capacity then that's no longer an issue.

Sent from my SAMSUNG-SM-G920A using Tapatalk

Lots of folks aren't, so it might be useful to others.

The tongue weight rating is seldom because of the hitch - it's because of the way the truck needs to have the load distributed. Changing to a non-stock hitch might change the number slightly if the position of the tongue weight moves closer to the truck as a result. However, the published numbers from GM are what any police or lawyers are going to go by if there's a legal issue to contend with.

And, yes, if you are in an accident and your numbers are found to be off, and they can prove that you knowingly towed out of spec, your insurance can be voided and you wouldn't be covered. This is not the "Internet myth" that some folks here like to claim that it is. I'm not saying it happens all the time - I'm saying that it DOES happen, and it would suck to have it happen to you.

I had an '11 Tundra CrewMax that I pulled a well loaded 10k trailer with. The tongue weight on the truck was able to handle the tongue weight, I just needed the welded hitch mount to ALSO carry the weight (the screw on ball hitches are not rated to handle 10000/1000 lbs, only the welded ones are). With the weight properly distributed on the trailer to place the right tongue weight on the truck, it towed quite well and the truck rode pretty well while doing it.

ember1205 · July 4, 2015

If your to a point you have to use weight distribution to put weight on the steering axle you should really be looking into a bigger truck.

Wrong.

j-ten-ner · July 4, 2015

If your to a point you have to use weight distribution to put weight on the steering axle you should really be looking into a bigger truck.

I agree that a bigger truck can (should) handle the same trailer better than a smaller truck.

But in my case I think that I'm well within the specs of the towing capacity of the truck.

A 6000 lbs trailer (GVWR) is only 62.5% of the max trailer weight allowed for my truck.

I don't think that I'd need a bigger truck.

so long

j-ten-ner

BlackZ71Silverado · July 4, 2015

If your to a point you have to use weight distribution to put weight on the steering axle you should really be looking into a bigger truck.

That's incorrect.

A WDH is made to distribute the weight of the trailer which is obvious by the name. It helps balance the weights between the trailer tongue and the overall gross trailer weight. That allows you to stop, turn and steer the truck safely while carrying a heavy load. Without a WDH, the overall performance of the truck is changed due to the weight you are towing.

You can really tell a difference while towing if you have the truck set up properly and safely. The WDH not only help balance the weights, it keeps your vehicle safe and enables you to maintain a safe stopping distance and have better control of the truck. Without the WDH, stopping distance in increased greatly and the truck will be difficult to control.

You are not to the point of needing a bigger truck until the trailer you are towing exceeds the maximum weight rating of your 1500 series 1/2ton pickup.

Chevor · July 4, 2015

There's no point arguing with 1/2 a truckers they know everything.

Jon A · July 4, 2015

You didn't solve any problems with air bags - you masked it......Air bags don't do a THING to cause the weight to be carried differently by the truck, they merely reduce the squat.

This is all wrong. Airbags improve the capability of your suspension. They increase the suspension's ability to carry the weight. They directly address the cause of porpoising (lack of rear spring rate relative to the mass being carried). They will make the vehicle ride better, handle better, brake better and basically be safer in every way while carrying a heavy load or towing. No, they don't take the place of a WDH, what they are doing is different but in many ways just as useful.

WDH's also do something useful, but it's different. They improve the ride by introducing forces on the front and rear suspension "masking" the fact you have a large amount of mass on the rear suspension. The anti-sway attributes they can provide are also very usefull. Airbags alone will tend to reduce sway some by making the rear more solid, but in order to address it directly you need a WDH with a system built in.

they merely reduce the squat. Use a WDH and that squat will go away because you'll have your load distribution correct over both the front and rear axles of the truck.

That is over-using the WDH. It will make the vehicle less safe. It might ride and "feel better" on the road, but it will be less safe at the limits of handling. Much testing has been done in recent years and now GM advises to use only a 50% FALR with their 1/2 tons (if the front fender rises 2" when you hook up the trailer, tighten the bars until the front fenders come down only 1"). Ford now states to only use 25%. It has been found that the more weight you transfer with a WDH the less safe you are making the vehicle. If you crank it to the point the rear has "no squat" left, you have way over-done it and made the vehicle much more likely to jacknife.

If you over-do it, this can cause you problems in an emergency manuver because you haven't really moved any mass. All that mass is still over the rear tires, but if you lift up on the rear suspension hard enough with a WDH, the rear tires no longer have the traction required to handle that mass around a corner without skidding--at which point you jacknife.

I know it ticks people off to hear what they've been doing for years is wrong, but the facts are the facts. We simply have better information now. If you think cranking more weight to the front with a WDH than GM, Ford and the SAE recommend is somehow making you safer, you're fooling yourself.

The safest setup, of course, is both improving the suspension with a set of airbags and using a good WDH with sway control but only transfering a modest amount of weight per GM's guidelines (with airbags you can have a good ride without "overdoing it" with the WDH).

ember1205 · July 4, 2015

This is all wrong. Airbags improve the capability of your suspension. They increase the suspension's ability to carry the weight. They directly address the cause of porpoising (lack of rear spring rate relative to the mass being carried). They will make the vehicle ride better, handle better, brake better and basically be safer in every way while carrying a heavy load or towing. No, they don't take the place of a WDH, what they are doing is different but in many ways just as useful.

WDH's also do something useful, but it's different. They improve the ride by introducing forces on the front and rear suspension "masking" the fact you have a large amount of mass on the rear suspension. The anti-sway attributes they can provide are also very usefull. Airbags alone will tend to reduce sway some by making the rear more solid, but in order to address it directly you need a WDH with a system built in.

That is over-using the WDH. It will make the vehicle less safe. It might ride and "feel better" on the road, but it will be less safe at the limits of handling. Much testing has been done in recent years and now GM advises to use only a 50% FALR with their 1/2 tons (if the front fender rises 2" when you hook up the trailer, tighten the bars until the front fenders come down only 1"). Ford now states to only use 25%. It has been found that the more weight you transfer with a WDH the less safe you are making the vehicle. If you crank it to the point the rear has "no squat" left, you have way over-done it and made the vehicle much more likely to jacknife.

If you over-do it, this can cause you problems in an emergency manuver because you haven't really moved any mass. All that mass is still over the rear tires, but if you lift up on the rear suspension hard enough with a WDH, the rear tires no longer have the traction required to handle that mass around a corner without skidding--at which point you jacknife.

I know it ticks people off to hear what they've been doing for years is wrong, but the facts are the facts. We simply have better information now. If you think cranking more weight to the front with a WDH than GM, Ford and the SAE recommend is somehow making you safer, you're fooling yourself.

The safest setup, of course, is both improving the suspension with a set of airbags and using a good WDH with sway control but only transfering a modest amount of weight per GM's guidelines (with airbags you can have a good ride without "overdoing it" with the WDH).

Where did I say ANYTHING about transferring more weight than recommended? You completely mis-read my post as I was advocating for REDUCING the overloaded weight carrying at the rear (which directly LOWERS the weight carried up front - ever heard of a lever?) and transferring some of it to the front where it belongs.

When the load that the vehicle must carry directly is properly distributed over both axles, it WILL ride better. Drop 1500lbs of weight in your bed behind the axle and tell me how great your truck rides and handles... Load distribution makes the vehicle safe.

j-ten-ner · July 5, 2015

...That is over-using the WDH. It will make the vehicle less safe. It might ride and "feel better" on the road, but it will be less safe at the limits of handling...If you crank it to the point the rear has "no squat" left, you have way over-done it and made the vehicle much more likely to jacknife.

If you over-do it, this can cause you problems in an emergency manuver because you haven't really moved any mass. All that mass is still over the rear tires, but if you lift up on the rear suspension hard enough with a WDH, the rear tires no longer have the traction required to handle that mass around a corner without skidding--at which point you jacknife.

I know it ticks people off to hear what they've been doing for years is wrong, but the facts are the facts. We simply have better information now. If you think cranking more weight to the front with a WDH than GM, Ford and the SAE recommend is somehow making you safer, you're fooling yourself.

The safest setup, of course, is both improving the suspension with a set of airbags and using a good WDH with sway control but only transfering a modest amount of weight per GM's guidelines (with airbags you can have a good ride without "overdoing it" with the WDH).

I'm sure when there was so much testing done that it will be pointed out in the manual for the WDH and how to use it right.

And of course nobody is talking about "overdoing" it.

My understanding is that the WDH helps you to distribute/spread the load to the front of the tow vehicle and the rear of the trailer.

It is not meant to lift the rear wheels of the ground. I think we can agree on that.

Since the brake power is roughly split 80% front axle and 20% rear axle I'd rather have the WDH to take some of the load off the rear axle and "transfer" it to the front.

And there is also the proportioning valve what contributes to the brake power distribution in an emergency.

The only negative effect I can think of is that the whole trailer connection assembly is under tension. Kind of spring loaded so to speak. But there is no extra shock absorber. That means that the shocks on the truck and trailer have to work harder.

so long

j-ten-ner

Jon A · July 5, 2015

Where did I say ANYTHING about transferring more weight than recommended?

You said the WDH would make the "squat go away." If it does, you have transfered more weight to the front than you should. Any decent amount of tongue weight will make a 1/2 ton with the stock rear suspension squat a lot. The most a WDH should do is reduce this a little bit--not eliminate it or come anywhere close to doing that.

I was advocating for REDUCING the overloaded weight carrying at the rear (which directly LOWERS the weight carried up front - ever heard of a lever?) and transferring some of it to the front where it belongs.

Obviously that's what you were talking about. You need to understand transferring too much weight to the front causes a safety issue.

When the load that the vehicle must carry directly is properly distributed over both axles, it WILL ride better. Drop 1500lbs of weight in your bed behind the axle and tell me how great your truck rides and handles... Load distribution makes the vehicle safe.

It rides better....right until you crash. It's not safer. There is simply no way to put any of that 1500 lbs on the front wheels safely (besides a gooseneck a little bit ahead of the rear axle). The most a WDH should ever be used for is to restore some of the weight removed from the front tires--GM says restore 1/2 of it, Ford says restor 1/4 of it. If your front fender is lower with everything hooked up than it is when the truck is empty, you are putting some of that weight on the front tires in addition to restoring 100% of what was lifted off and it's a very unsafe condition.

Yes, it may ride more nicely. But you are increasing the likelyhood of a crash if you need to swerve/stop, etc, quickly in the case of an emergency.

Jon A · July 5, 2015

I'm sure when there was so much testing done that it will be pointed out in the manual for the WDH and how to use it right.

Not necessarily. They aren't the ones who did the testing. Most WDH manufacturers are small companies that don't have the resources or expertise for full scale instrumented testing the way GM, Ford, etc, do. Some have recently updated their manuals/instructions to take the new recommendations into account, but don't count on that.

And of course nobody is talking about "overdoing" it.

Lots of people do it all the time. See above. They don't know that's what they're doing, but they are and people do it every day. They may be re-stating exactly what the WDH manual written 10-15 years ago said to do. We have better information now. I recommend people use it.

Since the brake power is roughly split 80% front axle and 20% rear axle I'd rather have the WDH to take some of the load off the rear axle and "transfer" it to the front.

And there is also the proportioning valve what contributes to the brake power distribution in an emergency.

When the truck is empty, 80% (or even a bit more) can be done by the front in a full stop. But the front doing 80% when towing a trailer would be quite dangerous. Luckily for years now all the big three have been using Electronic Brakeforce Distribution in conjuction with the ABS system so this does not occur. The rear brakes will be doing a lot more work when towing as they should, so it's a non-issue.

Keep in mind, it's not that much weight that gets transfered (unless you're "overdoing it"). Depending upon your wheelbase, hitch distance, etc, a 800 lb tongue weight will lift around 300 lbs off the front tires. According to GM's latest recommendations, you should only use the WDH to transfer 150 lbs of that back to the front. According to Ford, only do 75 lbs. That's practically nothing in the big picture.

ember1205 · July 5, 2015

When the truck is empty, 80% (or even a bit more) can be done by the front in a full stop. But the front doing 80% when towing a trailer would be quite dangerous. Luckily for years now all the big three have been using Electronic Brakeforce Distribution in conjuction with the ABS system so this does not occur. The rear brakes will be doing a lot more work when towing as they should, so it's a non-issue.

Keep in mind, it's not that much weight that gets transfered (unless you're "overdoing it"). Depending upon your wheelbase, hitch distance, etc, a 800 lb tongue weight will lift around 300 lbs off the front tires. According to GM's latest recommendations, you should only use the WDH to transfer 150 lbs of that back to the front. According to Ford, only do 75 lbs. That's practically nothing in the big picture.

First of all, your assumptions about how much braking work is handled by the rear breaks when trailering is off. By adding load (downward force as in cargo or tongue weight) to a truck, you MIGHT increase the braking percentage that the rear wheels will handle from 20% to 40%. You will also get more braking from the front because the process of braking actually shifts weight to the front axle and naturally increases the braking ability that is available there. That still leaves at least 60% being handled at the front axle. I don't know about you, but I don't want to be limited to 40% of my braking capacity when towing because there's too much weight being carried by the rear axle and the load on the front axle has been reduced as a result.

Second of all, you completely left out the fact that trailers over 3000lbs GTWR are required to have THEIR OWN BRAKES in many states (all?). This is because the tow vehicle is simply incapable of braking for itself and a heavy trailer regardless of where the load is being carried. This drastically reduces the relevance of the portion of braking capacity that gets shifted to the rear of a tow vehicle because of tongue weight.

Thirdly, your math is WAY off on figuring how much weight is llfted from the front axle. A max tongue weight rating is based on how much downward force can be carried before it starts to lighten the load at the front. The point at which the tongue weight is carried is quite a bit closer to the rear axle than the weight at the front of the truck. So, it's only a portion of the tongue weight that is seen "coming off" of the front of the truck. And, when you transfer small amounts of weight back to the front axle, that multiplier comes back into play to offset a larger amount of actual tongue weight in terms of lightening the front end. Meaning: Ford says to transfer 75lbs to the front because that's what was "lost", and in doing so, it balances out a couple hundred pounds of tongue weight that bear down on the rear axle.

ember1205 · July 5, 2015

It rides better....right until you crash. It's not safer. There is simply no way to put any of that 1500 lbs on the front wheels safely (besides a gooseneck a little bit ahead of the rear axle). The most a WDH should ever be used for is to restore some of the weight removed from the front tires--GM says restore 1/2 of it, Ford says restor 1/4 of it. If your front fender is lower with everything hooked up than it is when the truck is empty, you are putting some of that weight on the front tires in addition to restoring 100% of what was lifted off and it's a very unsafe condition.

Yes, it may ride more nicely. But you are increasing the likelyhood of a crash if you need to swerve/stop, etc, quickly in the case of an emergency.

The gooseneck moves weight to the front axle precisely because of what you state - it literally sits in front of the rear axle. A WDH is a perfectly safe means to provide a similar amount of weight transfer to the front axle for bumper-pull trailers. I've never once advocating for "overdoing it" and moving too much weight. Follow the manufacturer directions for the trailer, the hitch, and the WDH and you will achieve a safe towing setup.

Your blanket statement about the front fender being lower when hitched being not safe is technically incorrect. If you use a WDH to transfer tongue weight to the front axle is per the directions and specifications, your front fender WILL be lower than when you started because you're carrying tow weight on the front axle.

Now, if your front fender height decreases and your rear fender height does not, THAT is an issue. And guess what? All you need to accomplish that ridiculously unsafe condition is to load the cargo on the trailer too far back.

Stop crying wolf that using a WDH will make you crash by over-sensationalizing what has been said here. A WDH is like a hitch, a receiver, a trailer, or a tow vehicle in that there is a proper way to use them. Stray outside of that, and you're creating a hazard. Use them correctly and you are improving safety for you and everyone else around you while you tow.

j-ten-ner · July 5, 2015

Ok, let's agree not to "over-do it".

ABS, proportioning valve and the trailer brakes are taking care of the stopping procedure.

We will take turns at a reasonable speed and load the cargo correctly.

What brand or kind of a WDH would you recommend?

so long

j-ten-ner

ember1205 · July 5, 2015

I have no specific recommendation for a product brand or type, but I would seek one out by:

A) Talking with local trailer dealers to see what they offer and WHY they offer the one(s) that they do

B) Inquiring with others that have similar trailers and/or tow vehicles to see what they have used, how it has held up, how easy it is to adjust, etc.

C) If you have any scales in your area, possibly try and get some input from the operators as to what they have seen come across the scales that work well

With "C", you're also potentially opening up the door to getting some assistance with the setup and adjustment - a few rolls across the scales to get you set with appropriate weights on both truck axles as well as the trailer, and you'll be in great shape for the long (or short) haul.