Air bag and tire pressure

[billharr]

I would recomend that you separate the bags first.
that will probably make the biggest difference.
They should never be hooked together, because as air is pushed out of one it gets pushed into the other magnifying the effect.

This and raise the tire pressure. I have a 2005 Tundra, E tires, and Hellwig sway bar. Run 70 psi on the tires and 40 psi and 45 psi on the bags, cabinet side higher.

Running 40 psi on a tire rated for 80 psi will cause side wall flex and HEAT. Heat will cause tire failure. 10 ply tires will build much more heat than a 1 or two ply radial car tire.

 

[Vic Harder]

This and raise the tire pressure. I have a 2005 Tundra, E tires, and Hellwig sway bar. Run 70 psi on the tires and 40 psi and 45 psi on the bags, cabinet side higher.

Running 60 psi on a tire rated for 80 psi will cause side wall flex and HEAT. Heat will cause tire failure. 10 ply tires will build much more heat than a 1 or two ply radial car tire.

Bill, I'm not sure about that. My E rated tires are max 80 psi as well, and I run them at 60F, 55R (front of the truck is still heavier than the rear, even with the camper mounted!). This is based on contact patch shape and even contact all the way across the tires.

Vic

 

[billharr]

Bill, I'm not sure about that. My E rated tires are max 80 psi as well, and I run them at 60F, 55R (front of the truck is still heavier than the rear, even with the camper mounted!). This is based on contact patch shape and even contact all the way across the tires.

Vic

Vic I had a typo (corrected). OP said he was running 40 psi (1/2 of rated pressure) which might cause heat at speed.

 

[rando]

This and raise the tire pressure. I have a 2005 Tundra, E tires, and Hellwig sway bar. Run 70 psi on the tires and 40 psi and 45 psi on the bags, cabinet side higher.

Running 40 psi on a tire rated for 80 psi will cause side wall flex and HEAT. Heat will cause tire failure. 10 ply tires will build much more heat than a 1 or two ply radial car tire.

Just to be clear - what you are calling the 'rated pressure' is actually the maximum pressure for the tire. If you are running at the max load for the tire, you would want to inflate to this pressure, however you are not running at the maximum load so you don't want to be inflated to the maximum pressure as it will cause uneven wear and a harsh ride.

I am assuming these are not the stock tires for your Tundra, so figuring out the correct inflation pressure is not entirely straight forward - but Vic's advice on figuring out the correct pressure based on contact patch is good advice. Another way to calculate the correct pressure is to use a load/inflation table such as this one from Toyo:
https://toyo-arhxo0vh6d1oh9i0c.stackpathdns.com/media/2125/application_of_load_inflation_tables_20170203.pdf

This will give you an idea of what your pressure should be based on the tire size/rating and the weight of your truck.

 

[pvstoy]

Find a clean flat surface that is straight. Place chalk line across the tread on all 4 tires. Drive straight forward a short distance and stop. Look at the chalk and see where it is wearing off the tread. Wearing off middle than over inflated. Wearing off edges than under. Adjust tire pressure until you see a even wear across the tread. Now you have a good contact patch. Should do this when loaded and watch the tire temperature as you could be plus or minus with PSI. Check pressure when cold and note this as your cold tire pressure for your new tire size/type/rating as a starting point and adjust as needed. Just another method...

 

[rando]

To give a quick example of this - my Tacoma has a GVWR of 5600lb. Let's assume a worst case where I am over this by 1400lb, giving a total weight of 7000lb, 60% of which is on the rear axel. This means each rear tire has a load of 7000*.6*.5 = 2100lb. I have LT235/85R16 tires. Based on the load tables, I need to run a pressure of at least 50PSI for this worst case load, which would give me 2205 lb of load per tire. This means a load range 'C' or above tire. I am significantly under 7000lb and I usually run 50 - 55 PSI in the rear tires which gives a nice flat contact patch and a reasonable ride quality. But it is nice to verify that the my pressure agrees with the load tables.

 

[Squatch]

Best way to do this is to get your rig weighed. Total weight and each axle. Local feed store did mine. Contact your tire maker and give them the tires and size you are running. And then give them the axle weights and a description of the truck and camper. Ask them what pressure to run.

I did that with the Cooper STMAXX E rated tires on my '06 Tundra. For my load Cooper recommended 45+ front and 55 rear. I've been running that for 10k miles now and all is good. Tires are quieter on the road as well. I feel them at gas stops on long trips. All seem the same slightly warm temp. Even on hot days. Bulge is the same in all 4 corners as well.

You have a bigger truck and camper than mine.

For the airbags I measured the truck at all 4 wheel wells to the ground. I did this when truck was empty and no camper. Normal ride height. I then loaded the camper and set the airbags to come up to this normal level. About 2+" in my case. Between 28-30 psi in the airbags depending on load. It drives just like empty only heavier.

 

[pollux]

Rando: will this Old Man Emu D29XL Leaf Spring fits 2016 Tacoma 4x4?

 

[rando]

Rando: will this Old Man Emu D29XL Leaf Spring fits 2016 Tacoma 4x4?

Yes, if you already have a Old Man Emu CS047 leaf spring pack. This is an extra OME leaf designed to work with OME packs only, you can't add it to the stock Toyota leaf pack.

 

[Ronin]

On my '14 Tundra/Hawk rig I'm running 70 psi rear, 60 psi front on E rated tires. My Firestone Ride Rites are at 30 psi. My local tire pro says running at 40 lbs with a load will overheat the tires. On a recent trip total weight for my Tundra, Hawk, supplies, and myself was 7920 lbs.
Rando, thanks for the load/inflation table - one of these days I'm going to work mine out.

 

[ottorogers]

Same here...loaded '16 Hawk on '05 AC Cab Tundra...currently "D" tires at 50 psi and 32 psi left air bag and 28 right air bag....I equalized [air pressures for height and load] height until the top of each fender well is 35"...I do have an anti-sway bar on rear which greatly reduced any sway..

50PSI front and rear???

 

[Stalking Light]

I run 50 in the front and 55 in the rear on my Tacoma, but I have an ARB frint bumper/winch and an Aluminess rear bumper w/deluxe box and spare mount so that changes the dynamics.

 

[Wallowa]

50PSI front and rear???

Yes..50 psi is the max pressure/max load pressure on the Toyo ATII D-rated tires...

Again....I first make certain the tire pressure is correct for the weight carried and yes I have weighed the front/rear and total vehicle fully loaded for a trip..

Next I use the air bags to level all four corners of the Tundra, as I stated at 50 psi and using the air bags @ 34/28 psi I raise the back of the Tundra so that the top of wheel wells are 35 " off the shop floor and the same as the front wheel wells @ 35".

The air bag leveling and anti-sway bar have made a huge difference in on road and off road stability...much, much less side to side movement [tipping] on road or off road and rear stability in two wheel drive on road....

I am also carrying a Warn multi-mount Zeno 8 winch on the front, 100 lbs, and no added weight to rear with only solar on roof.

Works for me....will go to "E" tires when "D"s wear out since our travel is mostly off road..

Phil

 

[So Cal Adventurer]

Out of curiosity... Are you guys airing down offroad??

I have a Tundra DC 4x4 with E rated tires and just a leer shell (FWC on the way) and run at 40psi front and 45psi rear. Which by reading the info here I should raise that to 55/50.

When offroad I air down to 25psi all around.

I run 35" Nitto Terra Grapplers and spend a lot time offroad. The last set lasted me almost 50k

 

[Wallowa]

Out of curiosity... Are you guys airing down offroad??

I have a Tundra DC 4x4 with E rated tires and just a leer shell (FWC on the way) and run at 40psi front and 45psi rear. Which by reading the info here I should raise that to 55/50.

When offroad I air down to 25psi all around.

I run 35" Nitto Terra Grapplers and spend a lot time offroad. The last set lasted me almost 50k

Just me...'05 Tundra '16 Hawk...but i only air down when it is required to get traction to get me out or through low traction surfaces..then air right back up..as a side note: Airing down lengthens the contact patch, not widen it as i first thought, but the sidewalls become distended [less on your "E" tires than my "D"s] and vulnerable to sidewall damage...

Slow speed goes with airing down thus excessive carcass heat [more chance failure and punctures as rubber heats up] from lower pressure and more flexing does not become an issue...even less with your "E"s...

Back on higher speed roads, back to correct weight load pressures..

Just me and I could be wrong!

Phil

 

[ottorogers]

Yes..50 psi is the max pressure/max load pressure on the Toyo ATII D-rated tires...

Again....I first make certain the tire pressure is correct for the weight carried and yes I have weighed the front/rear and total vehicle fully loaded for a trip..

Next I use the air bags to level all four corners of the Tundra, as I stated at 50 psi and using the air bags @ 34/28 psi I raise the back of the Tundra so that the top of wheel wells are 35 " off the shop floor and the same as the front wheel wells @ 35".

The air bag leveling and anti-sway bar have made a huge difference in on road and off road stability...much, much less side to side movement [tipping] on road or off road and rear stability in two wheel drive on road....

I am also carrying a Warn multi-mount Zeno 8 winch on the front, 100 lbs, and no added weight to rear with only solar on roof.

Works for me....will go to "E" tires when "D"s wear out since our travel is mostly off road..

Phil

thanks Phil, I’m at 55 psi in airbags, tried 50 psi in rear tires, still getting away, I’ll try 70 in airbags, then I give up

 

[ottorogers]

Out of curiosity... Are you guys airing down offroad??

I have a Tundra DC 4x4 with E rated tires and just a leer shell (FWC on the way) and run at 40psi front and 45psi rear. Which by reading the info here I should raise that to 55/50.

When offroad I air down to 25psi all around.

I run 35" Nitto Terra Grapplers and spend a lot time offroad. The last set lasted me almost 50k

wow 50k wear is very good, I just got General Grabber X3’s and so far they are great

 

[Wallowa]

thanks Phil, I’m at 55 psi in airbags, tried 50 psi in rear tires, still getting away, I’ll try 70 in airbags, then I give up

Otto,

I am no expert...and mainly learn empirically by doing...but perhaps the swaying is induced by the height of your combination...10 ply tires may do two things...raise the CG [if dia. is increased] and not flex to compensate for the side loading at higher pressures...I would experiment with tire pressures that will just carry the load you have with the rating of those tires and then try to equalize the fore and aft height at the fender wells as I described using the air bags...intuitively less pressure in tires or air bags while leveling out the rig may allow a more compliant ride and not a stiff roll...also my Hellwig sway bar has settings that allow fine tuning the torsional effects...so in the end, if you do not have a lot of load on the roof to greatly raise the CG.... I would juggle the tire pressures, air bag pressures and anti-sway bar settings one at a time to try and find the best setting..there most probably is a "sweet spot".

Good luck!

Phil

 

[So Cal Adventurer]

wow 50k wear is very good, I just got General Grabber X3’s and so far they are great

Yeah, I was VERY impressed with their performance AND their longevity. So much so I bought another set

 

[So Cal Adventurer]

thanks Phil, I’m at 55 psi in airbags, tried 50 psi in rear tires, still getting away, I’ll try 70 in airbags, then I give up

What are you running for springs???

My current setup is close to the weight of a FWC in my Tundra and almost zero sway.