How to keep a TRD Pro from squatting while towing?

Having trailer brakes wont have stop a loose load in a trailer from shifting forward. Air bags do not solve the weight issue. Air bags are like a cosmetic fix for squat, so to speak.

 

Not securing loose loads is a totally different discussion. Planes have the same problem from people that don't know what they are doing.
Nor does a hitch solve a weight issue.
Cosmetic ? That's funny. Tell that to Firestone engineers. They need a good laugh.

 

Don't forget that in that same hard braking maneuver the truck itself will tend to dive and lift the rear countering to some extent the weight shift onto the tongue. Air bags plus leaves increase the spring rate on the rear axle. I've only had them up to 60 psi for ~1200lb payload on the stock 5-lug leaf pack so they're pleny capable of handling tongue weight. If the trailer is loaded hill billy style then weight shift could definitely be a problem though(chances are if that's the case then the truck will also be at least as overloaded and all bets are off).

 

Air bags have zero effect on the axle load. That comes entirely from the weight of/in the bed. All the bags do is change the distance between the frame and the axle, same as a heavy duty leaf pack.

 

Airbags and weight distribution hitches are not the same. Yet every thread where I see the a WDH should be used people are singing the praises of airbags.

Wish everyone had seen that airbag vs WDH video someone posted ages ago. They put the truck and trailer on individual scales and then compared the airbags inflated to the WDH being installed. Since I care more about performance than how the truck looks it sold me on WDH.

 

WD hitches are the smarter choice for bumper pull tow vehicles. Trucks pulling 5th wheels benefit more from air bags since they are really the only option. WD hitches are proven to reduce squat and improve vehicle handling while towing. It's really simple, the WD hitch balances the weight placed on the tow vehicle axles. Putting weight on the rear is transferring weight away from the front axle which is reducing your steering and braking ability. Air bags are only lifting the rear of the truck up. The WD hitch is doing the same by equalizing the load on the tow vehicle axles and transferring some weight back to the trailer, relieving some of the burden on the truck. In an extreme scenario, stiff air bags that do not squat enough will cause a heavily loaded trailer to raise the whole front of the truck up when the rear suspension is unable to squat enough and the weight in the trailer shifts forward in a hard braking incident. Locking up the trailer brakes will cause this too. Or think of a truck with fully inflated bags and a 1000lb payload or tall object in the bed. The higher center of gravity puts this truck at greater risk of tipping then a truck without any sort of helper springs.

https://m.youtube.com/watch?v=XBZu39pQ8Gg

https://youtu.be/NNIWCQlRdaw

 

That equalizer video was the one I was thinking of.

 

Nice video. I completely agree that a WD hitch is best for towing heavy loads. I noticed that they exceeded proper tongue weight by ~ 100%. 4000lb gvw trailer should have 360-600lb tongue weight(9-15%), not 1000lb(25%) as they demonstrated. I somehow doubt there would be much to demonstrate otherwise.
The point was not that WD hitches aren't the right choice in certain circumstances but that it is erroneous to state that air bags cause axles to crack any more than a stiffer leaf pack would, quite the contrary since leaf packs have a fixed reponse. What does happen is that the stiffer the suspension is the more force it takes to induce wheel travel and absorb bumps/potholes. That force is transmitted through the axle bearings to the housing and on to the leaf pack/air bags but is still much less than that of the same impact with no springs at all. When lightly loaded a heavy duty leaf pack will impart more force on the axle than air bags that have been aired down to match the load because the air bags will allow more travel to absorb the impact.
A WD hitch is great when there's a trailer involved but doesn't help with ordinary bed loads.

" The higher center of gravity puts this truck at greater risk of tipping then a truck without any sort of helper springs."
I have to disagree, too soft springs will cause a load to sway much more than one with either the correct spring rate or even springs too stiff even with the few inches of regained ride height. The initial tipping from the soft springs allows the load lateral momentum it cannot get with a stiffer suspension. In the later case the truck will hop and lose traction but it won't tip more than one with a weak suspension. SUV's with coil springs meant to give a soft ride are a prominent example of how bad the combination of a high center of gravity with a soft suspension is.

Bottom line,
Avoid bottoming out, it's bad for the axle, bearings, leaf springs, and shocks.
Load the trailer properly to be in the correct tongue weight range.
Use a WD hitch when necessary to prevent rear axle overload.
If you never carry loads in the bed and only haul heavy trailers then don't bother with air bags.
If you only carry heavy loads then just beef up the spring packs.
If you carry varying loads and aren't concerned about ride with the truck empty then get heavy duty leaf packs.
If you carry varying loads and want the spring rate to match the load then get air bags.

 

^This. Good summary.

 

Sumosprings, cost nothing, do magic, they can be taken off easily if you don't need them all the time

 

The tech at the Toyota dealership is where I heard the story from: that over-inflated airbags place tremendous stress on the axle and cracking is a result. I cannot tell you the geometry involved. I want to just warn people that may think if 25 psi is good, 50 or more is better... As you can see by my chart, there is no advantage above 35 psi (unloaded).

 

Doing anything wrong usually has unfortunate consequences. You wouldn't go rock crawling with 18psi in the tires and then jump on the freeway without airing back up. Having something adjustable requires more attention but also offers more precise capability.

Yes, over inflated will be approaching no suspension at all so every bump is a hit on the axles at the bearings but bottoming out causes those same hits so for the sake of longevity it's a good idea to set up your suspension to utilize enough travel to absorb bumps without bottoming out. I use mine for a broad range since the stock base 5-lug leaf packs are too soft for just the cap but otherwise unloaded so my minimum is ~20 psi and fully loaded ~60-65psi. Generally I have enough in the way of tools in the back that 35 psi feels right. Ride is much more stable and front/rear compress more nearly equally. As with anything it's important to understand what you're doing and the consequences of any mods as well as their limitations.

 

Not sure about the 5-lug airbag specs, but the specs for the 6-lug indicate 1 psi for every 50 pounds of load. Some folks say to use 40. So unless you are overloading your truck, you should never have to go over 25 psi. That's about the max I have ever used when fully loaded with mulch from Home Depot, and it was plenty of help.

I am typically running around with about 250# (rack, RTT, bed mat, some bins and tools, hitch bike rack). Any more than about 8 psi and the ride gets too stiff, so I keep them between 5 and 8.

 

Do you rebuild/repair electric motors?

 

No we build electric linear actuators and these motors are burnt up mostly and no good so we scrap them.

 

lol. valving doesnt control height. Valving helps control speed on compression and rebound. Springs control height. Stiffer valving can help control wallow under load but no matter what you do short of locking the valving out entirely nothing is going to keep weight from squatting the rear short of support bags, bumpstops or massive leaf springs.

 

Just for fun, let's reference the Owners Manual, just to clear the air a bit.

I will be using my 2017 AC 4x4.
Pg 173
Gross trailer weight over 2000 lb requires sway control.
Gross trailer weight over 5000 lb requires weight distribution hitch.

Trailer weight over 1000 lb requires brakes.
Trailer weight over 3000 lb recommends 2 or more axles.

For standard hitch, tongue weight 9% to 11% of trailer weight.
For weight distribution hitch, return front axle to same weight as before trailer connection. (Or till front fender is at same height as before connection).

So some conclusions from this data...
The one video had a ridiculous excessive tongue weight, which doesnt help their credibility much.
Brakes are required for a pretty small trailer.
Weight distribution hitch isnt required until pretty big trailer (and is pretty rare for boats especially with surge brakes). They do exist, but rare...
When using a weight distribution hitch, per Toyota you will still squat... (front axle load stays same and rear axle carries more load than before.) Much less squat than without a WDH, but still squat.


But, if you put your load in the bed, fill your airbags until off the bump stops when applying more than 2000+ lb in the bed, it works perfect. Ok, that last one may not be in the manual... but it is how I do it

 

I'm thinking Firestone bags for my Pro. I haven't settled on Cradles yet (a whole lot of Baja with my former rigs and never tore a bag). Lot's of discussion about WD hitches. Those are great, unless your boat trailer has surge brakes like mine (well, for the most part I suppose. There are some WDs that claim they can be used with surge brakes, but I dunno).

 

Hey, I just saw your Pro for sale on Nomad???
I have Ride-Rite Air Bags (by Firestone) on my 2010 Tacoma and the same airbags were on my 2005 Tacoma. They are great, and Baja Proven!

 

Hey DK. Yup, I need to go with Plan B. Can't even list here as I'm only at 48 posts.