Need some advise on beefing up the rear

I just picked up my first tundra and will using it to tow my 5th wheel 6700lbs with 1250 hitch weight. I've had bags on two of my old trucks and find them to work quite well while towing however I have had issues on both truck dealing with leaks tears and exhaust heat I end up having to replace both sets after some time. I wanna get your opinions on summo spring I like the idea install and forget but they do seem kinda gimmicky for towing heavier loads. With bags I can restore my ride height pushing that weight back onto the trailers axels, summo spring imo seem to just a act as a tall progressive bump stop? I don't really wanna add a leaf since I wont always be towing and not a fan of the stiff raised rear end hopping around without a load, been down that road on a Tacoma.

 

My trailer is a lot smaller than yours. Bumper pull, 500lbs tongue.
I run the lightest sumos. Unloaded they are stiffer, but ive come to tolerate it. I dont think i would want the HD ones unloaded. I have another set i cut down into bumpstops i swap in quickly if i want stock setup.

without the wdh, the trailer only sags me down an inch. They greatly increase stability while loaded. I brought home 3k lbs of DG and it wasnt even bottomed out.

Next load i did 1500lbs of DG and it felt controlled.

When loaded, i love them, they act like a sway bar too

 

Bags or an upgraded leaf pack would be advisable. I went with both... I've had bags on my truck for several years with zero issues in 100+ heat and -30F cold. As you noted, ride height can be restored using bags and they can be fine tuned for the load. That's exactly why I chose them over Sumo's or the like. I haul a similar weight in my bed most of the time. I also tow often with trailers of all weights and much prefer the flexibility and load handling with the airbags. Sorry to hear you had troubles with your last couple sets of airbags.

About a year ago, I upgraded my leaf pack with an Icon 3 leaf add a leaf; honestly, I would have chosen a different route had these not been touted as the bee's knees and I had them sitting in the garage unused for a couple of... ahem.. years... ahem. I think they would be great for a truck with a cap and a few accessories, but they could do better for heavy loads. They do better than the factory leaves, but leave some to be desired. But maybe that's a good compromise for you. I can't tell you how they ride with an unloaded truck because my truck hasn't been empty since I installed them. There are several other options for leaf springs like Icons, Dobinsons, ARB, etc but most produce 3" of lift. I wanted to stay to within an inch of stock which is also why I chose the 3 leaf add a leaf.

Alcan will build a custom back for your desired height and load characteristics for about $1200. I'm debating going that route. But for now, the bags and 3 leaf add a leaf are handling things very well. The only downside to airbags, IMO, is the very progressive nature of the air spring, which can limit up travel. But for hauling, they are great.

I've also added a TRD rear sway bar and E range tires for a stiffer ride.

 

@blenton whats your take on rear sway with bags?

now that i keep my sumos touching frame at ride height, the trd rear sway seems less important for cornering

 

https://activesuspension.com/products/toyota-tundra-1999-2020-hd

This with an upgraded spring pack would be my choice.

 

This is the real issue. Driver and the pin weight max out your payload and likely overload your rear axle.

 

Well, I ran a rear sway bar before I installed the bags. After I installed the bags, I pulled it and sold it to a buddy, thinking I didn't need it anymore. I plumbed my airbags independently so I can each side to offset any odd loading, as well as help mitigate sway; when the lines are plumbed to a single valve, cornering can force air from one bag to the other which doesn't do anything for sway. Well, after a few months I ended up ordering another sway bar. It has been installed ever since.

So I am a fan of both airbags and a sway bar.

Even though the air bags plumbed independently mitigate sway, I don't feel they are real replacement for a sway bar. A sway bar works by increasing the spring rate on the outside corner via the torsional force created or carried in the bar as it interacts with the chassis and axle that twist in when cornering. The spring rate increase from either airbags, stiffer leaf springs, Sumo's etc, is great for supporting the load, but in order to really counter the cornering force, they often need to be over sprung which can produce a rough ride no matter the load. The sway bar creates an variable spring rate that is essentially zero when traveling straight or when both wheels travel the same direction, but increases as the weight shifts from side to side. It also has the side effect of limiting down travel on the inside wheel since a larger difference in wheel-to-axle height creates a larger counteracting spring force on the outside wheel (the inside wheel extends down while the outside wheel gets compressed in to the wheel well in a corner). So it's kind of self regulating in a way, whereas stiffer springs on the axle ALWAYS pushing the axle down.

There is a particularly twisty road next to a reservoir that I frequent - sometimes with a trailer but almost always with a bed full of stuff. After re-installing the rear sway bar, there was a marked difference in handling on the corners, as well as the speed at which I could go around those corners in a controlled manner with minimal body roll.

So, again, my position is - these truck respond very well to a rear sway bar, even with airbags.

 

Unless I did the math wrong I think I’ll be just under maxed I hope that’s not overloading the tundras axle. Probably should clarify I do not do any sort of boondocking and the most I carry in the trailer is a case of water and some clothes always dump everything before leaving the camp ground.

 

Same. The cradles are great since they don't pull at the bag when the axle droops. They also make a monty-python-esqie 'clippity clop' when the bags leave the cradle then reengage which makes me spontaneously shout, 'Come along, Patsy!' to the befuddlement of any bystanders...

 

Toyota was nice and rated the rear axle to carry more than the full payload of the truck - usually 3 or 400 lbs more than payload rating.

 

I find that hard to believe. Payload on my truck is somewhere around 1275 lbs. You'll have a little more but remember that the 1250 lb pin weight doesn't include propane, batteries or anything else you put in a bone stock camper. Your payload also has to cover you and all passengers, all gear in the cab and bed of the truck, the pin weight of the trailer and the weight of the hitch itself.

 

I should be good then payload is 1,630lbs me the wife and dog are only 310lbs.

 

I Just looked into those cradles. Pretty cool design I think the cradles with the firestones are what I'll be going with.

 

If you’re gonna do bags, this is the setup you want. If you want it really nice, add an AirLift Wireless One compressor system. When I had that, I was able to mount the compressor and control box on the inner fender behind the air filter box.