Starting to question safety...

I was running my truck with only 2.5" of lift with stock control arms and it used to wander all over the road. You'll be surprised what more caster will do for the way it drives. My caster is now at about 3* and it tracks straight and can be driven with one finger and this is with 285/75/16 tires. I know what you are talking about because it's probably what my truck used to feel like. The only bad thing that can happen is if you wander out of your lane lol.
You can get away with stock UCA's but you're getting close to it being out of alignment spec or closer to the bad end of the spec.

 

Already at the bad end...

I'm at 1.6 and it wanders with 265s and the offset wheels. That's 2.5 lift on the stock UCAs. I hate to think how bad it is at 3 inches of lift.

 

By this, I meant stock take off wheels

 

I wanted to get an alignment but the guy at my garage basically told me it was useless because of our awful Quebec roads! One pot hole and itll be back to the way it is... i guess an alignment couldn't do any harm.
I just lowered all 4 tires to 45psi, i will see if it helps and if not, will start going through the other recommendations. Thanks a lot for all the help

 

Check your wheel bearings. Tighten them to spec and see if truck wanders after that. People start looking at everything else, but wierd wandering usually end up for me to be lose wheel bearings. If they bad they will completely go out on you after re tightening them.

 

Find a new garage!

 

That's a bunch of bullshit. I marked my alignment bolts to make sure they didn't move and they stayed put for a couple years now and several offroading trips. You need an alignment to figure out what your problem is. You'll get crappy tire wear with a crappy alignment.

 

You won't get proper alignment with 3" lift and stock UCAs. Just sayin'.

 

so youre saying i either just get used to it or i get new UCAs?

 

Yup, your caster will be too low with 3" of lift. So yeah, if you don't get UCA's that correct your caster then you will probably have to get used to the wandering. And you won't know how bad your alignment is until you get one.

 

yea for caster measurement if u run like 2.5 deg should be good .

 

Door Ding is 100% right

 

Yes. You or someone else could be killed or maimed.

 

That brings back memories doording. Back in the late 70s the State Patrol brought a similar 1960s film and slide show into our drivers ed class. The old films they showed in health class weren't much better

 

I'm not even going to watch that video because i know it'll play with my mind! haha
I called a new garage today, this guy seems to know more about lifted trucks.
he said i can bring it in early next week and hes gona check everything out for me.. Hopefully he can figure out the problem!
I lowered my tires to 45psi and i have to admit, it for sure helped!
But i do still find my steering wheel turns when i hit a bump. i dont swerve as much though... the ride is much smoother too.
At 65psi, the ride was pretty rough! My dad got in my truck for the first time in a while and he couldnt believe how rough it was.

 

65PSI

Even 45 seems high.

I run 32 psi in my 285/70R17 LT load range E tires.

The amount of air you need in the tires is determined by the weight of the truck, not the "maximum" pressure on the sidewall.

 

Take door ding's advice and have everything checked out. Then have it aligned. Shoot for 0 toe, 0 camber, and as high of caster as the shop can get. Then see how it feels, before blowing more money on UCAs.

 

Will take your advice!
Thanks

 

So you think i should go down even more?
By the way... how does tire pressure effect gas mileage? Would i of been burning more gas being at 65psi?

 

No, it just about matches what Toyota recommends. See below.

Your tire is a very different size from his. Load inflation tables differ significantly for different size tires.

For your tires, translating the recommended P265/70R16 TRD OR Rugged Fail placard information of 29 front and 32 rear we get recommended pressures for your LT285/70R17 of 33 and 35 PSI.

Translating the Baja/Pro LT265/70R16 placard information of 46 front and rear we get a recommended pressure for your tires of 37 PSI front and rear.

So you are running a bit low from what the placard would likely say if Toyota put your tires on from the factory. And in fact LT tires don't even have inflation tables below 35 PSI.

But that's fine really, you probably did a chalk test to come up with your pressure (I hope) and have checked your cold to hot pressure rise (I hope) and it wasn't much more than 4 PSI and you are happy with your ride. If that's all true then 32 PSI is the number for you. But it isn't the number for the OP who has a very different sized tire with a rather different load inflation table.

Last part definitely, first part yes and no. Indeed as you put more load on the tire you should put more air in it and it would be really unusual for that to come anywhere close to the maximum written on the sidewall. But the actual recommended inflation rarely matches the axle load on the load inflation table for the tire. Usually the recommended pressure puts the load for the tire quite a bit above what the actual load is. The manufacturer considers the tire inflation in the ride comfort and handling of the vehicle and accounts for likely loads and maximum driving speeds along with fuel efficiency and tread wear. So that doesn't really give one "correct" pressure but rather a range of pressures with different trade offs in all the parameters mentioned.

The recommendation for determining tire pressure for a different sized tire then is to take the tire pressure from the manufacturer (what is on the door placard) and look up what the rated load for that tire is at that pressure. Then go to the load pressure curve for the new tire size and find what pressure is required for that load. Again - this is a starting point and not gospel but it is a good sanity check for whether you are way over or under inflated. Adjust from there with chalk test, pressure rise test, handling and so forth.

You certainly could try that, but probably not down to the 32 PSI that bjmoose is running.

For your tire size of LT275/65R16 if we translate the TRD OR and TRD Pro door placards as I did above for bjmoose we get estimated pressures for you of 40 front and 43 rear if we use the TRD OR placard as a starting point and 45 front and rear if we use the TRD Pro placard as the starting point.

So feel free to go down to 40 psi and see what you think. Getting much lower and you are drifting pretty significantly from what the manufacturer recommends.

As a side note, why is your "correct" pressure so different from bjmoose's? Because your tire size is very different from his. Besides the difference in rim size bjmoose's tire is wider than yours which requires less pressure for a given load compared to narrower and his aspect is taller than yours which also requires less pressure for a given load.

Tire load inflation curves are kind of hard to come by as they are part of a standard that is sold for around $400 and copyright protected. But some tire manufacturers publish excerpts from that standard for some of their tire sizes. If you spend time looking at those you'll see that:

• Inflation tables for LT and P are very different, for the same size tire LT requires much higher pressures
• Larger tires require less pressure for a given load
• The differences between common sizes on this board of LT tires is over 5 psi
• The difference between P and LT can be more than 15 psi

So taking someone's recommend pressure isn't a good idea unless they are running the same type (LT or P) as you in a very close size.

In general the higher the tire pressure the better the gas mileage. Unlikely you were burning more gas at 65 psi, but you can burn more if significantly under inflated (so you probably were at 25 psi).