Bump Steer

I have a second Gen Taco where the wheel pulls left and right when I hit bumps in the road. All the steering is brand new, including the rack and pinion. Power steering fluid was changed. upper and lower ball joint are brand new. CV axle are brand new. Brand new swaybar, links, and swaybar bushings. I have Bilstein 5100 on the first setting. They were on the second setting. The bump steer got better after lowering the setting but still not perfect. Is this a result of the .85” lift? The tie rods have a slight angle but not too much. Is this normal for lifted Tacos?

 

I would start with an alignment, I have a 6" lift and zero bumpsteer.

 

I just got alignment less than a month ago. It was within factory specs. I’ll see if I can get a print out.

 

this means nothing

 

How so?

 

Could a weak power steering pump cause it?

 

Factory specs is a cop out used by turn and burn alignment and tire shops. If you are on the bad side of "factory specs" your alignment will be abysmal, if you're in the middle, still sucks.

If you have an alignment sheet, post it.

 

Right on. I’ll have to go to the shop. They’ll have it on file.

 

To elaborate. 2* of caster is typically right on the mark for "factory" but imo thats not enough. Couple that with any other sort of meh alignment numbers and ya my truck had bump steer too

 

And if I remember correctly, the caster was actually less than two is more like one and a half. Do I have to get upgraded control arms to increase the caster? I still have a factory control arms.

 

You say you have 5100s on the lowest setting?? What springs? A little more info on your suspension and maybe we can speculate a bit more accurately

Sounds like you are just experiencing really low caster. How to fix it depends on how much lift you are getting out of what springs.

 

I had my truck aligned twice and once by an 'off-road' shop. All any of them ever did was set the toe-in. Everything 'was in spec' but the truck wandered a little on the highway, and I wasn't satisfied with my tire wear.
Finally, I found a shop near where I work (in the not so pretty part of Louisville), who has a guy there who really knows his stuff. Before he aligned it, he looked at the tires, adjusted alignment cams, etc. It drives WAY better now and I've since taken my daughter's car to him as well.
It sucks that you have to hunt around for someone to do a GOOD alignment, but after you lift a vehicle, it can be a finicky.

 

Im using the springs that came with the truck. It had the 5100 on it and they were set to the second level. They look to be stock springs though.

 

I lowered the setting to the first level and got an alignment after recommendation from another mechanic. He said that if I wanted it set to the second level I should get new control arms to increase castor. But I just went to a 4*4 lifted truck shop told them about my issue and asked about new control arms and that guy sayid my tie rod angle is probably off? He didnt look at my truck)

 

Okay, so working with those assumptions, your truck being stock height... you should be able to get caster more than 2 deg, maybe quite a bit more. If a good alignment shop can't get those numbers, it's probably due to the eccentrics in the LCAs being seized such that they can't utilize all the adjustment range. At stock height there's really no reason to get UCAs, at least that's my understanding.

So either you aren't at stock ride height or your alignment is just off.

 

I’m going to have to find another shop I guess. It’s getting expensive though to keep being an alignment for nothing. Good riddance. Thanks for the advice.

 

alignment is not toe. Alignment is toe camber and caster. 0 toe with messed up caster and camber means you will have tire wear and bad steering characteristics.

 

Ok, update on my situation. As it goes, I have a 2013 4 x 4 Toyota Tacoma 2nd gen. I’ve got upgraded upper control arms on the front for a 2 to 4 inch lift. I’ve got brand new lower control arms on it. Brand new rack and pinion made from Edleman. Brand new outer tie rod from Moog. Brand new swaybar links, and swaybar bushings. Brand new CV axles. Brand new Bilstein 5100s set at the top setting (About 2”). Tires are 265/70/16 cooper discoverer at3. I’ve been having really bad bump steer on rough terrain. It was happening on even smaller stuff and little bumps in the road and wandering at high speeds but after installing the upper control arm and getting higher caster on my alignment, the wandering and small bump steer has seem to go away, but I’m still having bump steer with larger bumps. I have no idea what to do from here. Here are my alignment specs below. Any advice is appreciated. I see all sorts of forums here on this subject, but never any clear information on how to resolve or whether they are resolved other than just increasing the caster and upgraded control arms

 

What you are describing as bump steer may or may not meet the technical definition, but your new alignment looks good. You had too much negative toe on both sides, IMO, which could lean to twitchiness, but your before caster is respectable. Your after is even better, and with that much caster it should be pretty stable.

It seems like you've thrown a lot of money at the proper components. How many inches lift did you end up getting?

 

Ok the alignment specs before alignment above are after I installed new upper control arms. That’s why they are off. It’s lifted 2”. Whenever I run over uneven terrain the steering wheel pulls left and right. Can you post videos on here? I’ll record it.