Truck difficult to control

I know this alignment spec is on my 02 DC Pre Runner but I had issues with bump steer after having Discount Tire do my alignment 2 years ago

Bump steer was so bad that any road imperfections like degraded road conditions ... bumps , road patches or even man hole covers would cause the truck to violently move to the right or left sometimes out of my lane

I had Firestone do my alignment a couple months ago and now it's much better and no more bump steer . I was told by the Firestone alignment tech that Discount tire didn't account for the suspension lift when they aligned it

Before (notice camber /caster readings)






After ......

 

I wanted to clarify; that only applies to standard load P-metric and euro-metric tires.

 

I thought the opposite was true. Tire shop filled mine to 50 psi once, kinda terrifying ride home. I dropped them to 35 and the truck felt much more controllable.

 

What kind of tires were you using? I used to fill my first Gen tires to 50 psi, they were KO2’s, and it always made my highway mileage so much better, then I would air down for off road.

I drive on and off road so often now that I keep them at around 35-40 psi on my current truck, it also helps with lessening the amount of wear on the suspension.

 

Lets see, Uniroyal Tiger Paws on the Rav4, Goodyear Wrangler Fortitude on my truck, Michelin MS2 on the 92, some other brands on other family members cars I cant cant remember. Anyways, all get 35 psi. All get good, if not great mileage for the type of vehicle they are. All have even tire wear. 50psi not only made my truck ride like a ping pong ball, but it made the brakes feel really weird. I cant really describe it, but it went back to normal after I dropped them down to 35.

 

Rotate tires and see if it goes away. If so it’s a bad or unbalanced tire since you aligned it.

Check the front shocks.

 

35psi is not low and 50 is overinflated. I'm talking about 20psi low

 

It all depends on the size of the tire, 35 is under inflated and 50 psi is not overinflated for some.

 

You mean rating. And on stock tacoma tires as OP has, 50 is overinflated

 

Well rating does have a lot to do with it, but the larger a tire, the less pressure it actually needs in order to be able to support the same load. If you increase the load, then you do have to increase the pressure as well. The rating has to do with how the tire is built and that does affect the pressure and load requirements.

 

my truck does the same, im lifted and have 33s so i always assumed that was it. i have new jba ucas sitting in my garage thinking the higher caster will help once i find some time to install. but basically on the interstate it follows any and all imperfections on the road making for a crazy ride sometimes. have a sweet passenger seat shake sometimes too. tires have been road force balanced.

 

Mine did this stock as well as now with a 1.75” lift and 255/85r16s. There is a lot of play in the wheel when going straight at higher speeds, which requires constant input. The truck seems to wander back and forth still. A gust of wind can put me close to the line of whatever lane I’m in, more so than any other vehicle I’ve driven. I’ve had it aligned after the new tires were added and after the lift. I mentioned the play in steering to the service department at my 10k service and was told that is a common complaint and that it can’t be tightened. 2018 DCLB OR.

 

Thanks, it's a good reference. Your after numbers are quite similar to what I had when the tech first hooked up the machine.

 

Yep. Did a rotation, no change. I checked all shocks and no noticeable leaks or anything lose.

 

Sounds like a typical dealer response. I don't seem to have play in my steering, but I get pulled around. We'll see if my dealer is any help. My appointment is next Thurs. I'll keep everyone updated on what I find out.

 

I would say that has more to do with the tire size you are running, that 255 85 has a lot of sidewall. More sidewall, more tire flex.
But, if I remember someone around here had a third gen with worn steering rack bushings according to the dealer they used. Might be worth a look.

 

I've been following this with some interest. I thought I was the only person experiencing this but a quick google search makes it seem like I'm not alone.

Some data points I've noticed.

On some roads it'll track really straight but on most roads due to ruts, crown, wind, passing another car, etc it drifts a bit and if I have to apply the slightest pressure to keep the wheel off center it begins to wander. I'm talking the top of the steering wheel rim being 1mm off center. And then it's begins to go all over the road.

On alignments...I had the dealer do an alignment, wasn't good, had them recheck and they had to make some tweak. I immediately noticed it wasn't good. Went to private alignment shop where that's all they do. All these places gave me the usual print out of before and after. And the after and before between alignments wasn't consistent - meaning right after the dealer did their first alignment I went back in a few days, the before numbers in the 2nd trip weren't even close to the after numbers in first alignment. Ditto again for the 3rd alignment. There must be some variability on how to attach the alignment things to the rims.

Anyway, some suggest the bushings that hold the steering rack in place have too much play and need to be replaced. I haven't heard any before/after testimonials for anybody that has tried.

 

These trucks have hydraulic steering assist. It’s not drive-by-wire.

 

Just subbed, hopefully op you'll find a resolution. I too have a similar issue. Going to get another alignment and see if the tech can max out the caster as much as possible to see if that helps. My truck at speed (hwy/fwy speed) stays pretty true and straight. I get sloppy and jerky steering at low speeds (I've had my lift for 4 months now and I can't remember if it was this way when it was stock, have heard tacomas have sloppy steering at lower speeds, is this true?) . I am lifted 2 inches on a TOYTEC lift with SPC UCA,also have brand new bfg ko2s.