Truck difficult to control

Sure seems like every person I've seen with my same complaint has been using the stock OR wheels too.

 

You definitely seem to know more about scrub than anyone I've come across before. Thank you for explaining all of this.

What about the above with a 1.5" lift?

 

Thanks for the update! This is very interesting. I haven't done much with mine in quite a while. Been driving my other car most of the time and procrastinating figuring out the truck. I have the stock OR wheels on mine, too. Now I need to decide if I want to buy new tires, spacers, or both... lol

 

Depends on SAI and caster.
Lose SAI, gain positive scrub.
Higher caster, lose positive scrub.

Imagine both your upper ball joints in front of you. Now imagine the lower ball joints at 12 degrees outboard and 3 degrees forward of the upper balljoints. The 12 degree angle is SAI; the 3 degree angle is caster. This compound angle headed to the ground, is the axis about which the spindle rotates.

SAI provides stability and negates the need for high caster for stability.

 

I'm shopping around for new summer wheels now...17x8 15mm offset.

 

Broken leaf spring(s)....

Sorry, I see this is an old thread and I am not about to read 9 pages, but I have had a similar issue and I discovered a broken leaf spring.... I have had an add a leaf break as well as a main leaf.... the broken main leaf made the truck goofy to drive when hitting bumps at highway speed...

 

What size tire?

 

Two yrs ago we bought a low miles Mustang convertible with the same symptoms,only much worse. It had worn Pirelli P-Zero tires on it.New Good Year Eagle Sports and a toe adjustment cured it totally.

 

265 65 17 or maybe 265 70 17.

 

My trd offroad used to wander all over the roads, I swapped out the stock bilstiens for trd pro fox shocks and its night and day, no longer is it like a broken shopping cart.

Im interested to see if spacers help you as I wouldnt mind adding them to my truck too.

 

Are folks in this community trying to do too much with these trucks. I fail to understand why someone would change caster just to get a huge tire to fit. Ya Know? Sounds like you've done a few alignments in your day. Right?
Zim

 

Looks like you answered your own question.

 

Nope.
Just a guy who got tired of 'bad alignments' and found it was a lot more complicated than "3, 0, 0".

 

Point being, if you're using 2 different tire/wheel packages with differing scrub radius, they're dynamic toe will differ along with dynamic camber.
The one with higher positive scrub will require more positive toe.

 

I make that same drive up over the Sierras going to Nevada Gold prospecting several times a yr from Calif, the cement road has wear, deep ruts up to 6" deep, from truckers 18 wheelers, and your tires just don't fit well in a worn track by 18 wheelers, I am all over the road towing my Side By Side up there. Dangerous for sure. Only way to avoid is stay in fast lane with hammer down. But thats not me I do it the hard way in the slow lane since towing SXS. I fight it all the way over. Every time. I have modified suspension with much larger dia shocks, nothing is gonna fix that wandering, the worn ruts from the semi's are wider than a Tacoma wheel width so your constantly correcting, sometime the deepest ruts will throw your vehicle radically sideways, no kidding those ruts are very deep in some areas on 80. No amount of alignment is gonna fix it. State of Calif is only one that can fix your problem, hehe.

 

Do you have the TRD Pro vs Stock OR offsets backwards? Shouldn't more offset should give you more track width?

 

That's true when talking about negative offsets. When talking about positive offsets the lower offset will have greater track.
Less track~25mm<15mm<0mm <-15mm<-25mm~More track

 

I'm still in the stock configuration. 16x7 25mm offset.

 

I would go 265/70/17; this adds only 6mm of positive scrub.
A 265/65/17 would add 10mm of positive scrub.
A 285/70/17, or similar overall diameter, would be perfect, as scrub radius would be unchanged.

 

i have something similar and I have a 17OR the truck easily beers to the left going highway speeds. It maybe because I have 36 in my tires BF KO2 or maybe I need an alignment. This only happens on the highway. Hope you find the problem