Weird vibration when accelerating from a stop

[eljefe]

Hey all. I've had my Bilstein lift for a few years now and run some 35/12.50/18 AT tires with roughly 15k miles on them, and I really never paid attention to it since I used the most reliable offroad installer in a wide swath of our area. I've noticed over the past 3 to 4 months that when I'm turning under acceleration, either right or left, from a dead stop it feels like the truck is in all wheel drive. The tires give a vibration through the steering wheel like the outside bites on my AT tires are gripping the road. The truck has 78k miles, mostly road but some beach driving.

Two pics each with questions.
1) the one with my finger pointing is it common for the from sway bar to look like it adjust from side to side? The bushings don't look dry rotted, breaking apart, or too squished.
2) Drawing a blank on what the part is called that is circled in yellow. I know it's not appropriate for the boot to be squished/crushed like that. Recommendations on how to upgrade that part and any other OEM you think is required to make my front end safer?

Thanks in advance.

 

[heckcat9]

The part you circled in yellow is the sway bar endlink. You should consider extended links if the front end is lifted.

My sway bar has a little less lateral play but I also bought this truck used a month ago so I'm not sure how much lateral movement in the bushings is normal for these trucks lol. Looking forward to seeing what others say... I'm going to replace my bushings and endlinks now anyway though.

Is the vibration only while turning under acceleration or does it occur while turning without throttle as well?

 

[kurek]

The sway bar end link angle is pretty normal, not like the geometry there can change much anyway unless you've lifted the front using spacers.

Sway bar movement side to side a tiny bit is normal.

Neither of those things would make the vehicle crab walk.

Improper caster could easily produce funky enough steering geometry for you to feel it when you're cornering. If you have the Bilsteins at 2.8" and stock control arms it might be that the shop traded a little caster in order to get acceptable camber within the range available since both of those measures are adjusted using the same two cams on either lower control arm. Solution would be lower it to 2.1" or 1.4" and get it realigned or install lift specific upper control arms that are corrected for the raised ride height and then get it realigned.

If you post up photos of your alignment cams (both sides, front and back of lower control arm where it joins the frame) it might be possible to infer whether that's likely.

 

[eljefe]

The sway bar end link angle is pretty normal, not like the geometry there can change much anyway unless you've lifted the front using spacers.

Sway bar movement side to side a tiny bit is normal.

Neither of those things would make the vehicle crab walk.

Improper caster could easily produce funky enough steering geometry for you to feel it when you're cornering. If you have the Bilsteins at 2.8" and stock control arms it might be that the shop traded a little caster in order to get acceptable camber within the range available since both of those measures are adjusted using the same two cams on either lower control arm. Solution would be lower it to 2.1" or 1.4" and get it realigned or install lift specific upper control arms that are corrected for the raised ride height and then get it realigned.

If you post up photos of your alignment cams (both sides, front and back of lower control arm where it joins the frame) it might be possible to infer whether that's likely.

 

[eljefe]

Now that I see these camber pics it looke like tire rub? It only makes the noise turning under acceleration.

 

[heckcat9]

12.5 wide tires on wheels with factory backspacing do get close to the upper arms... Definitely looks like yours are occasionaly rubbing. Do they touch the control arms at full steering lock?

The alignment cams kurek wanted to see are on the lower control arms where they mount to the frame.

 

[kurek]

Those are the upper ball joints. That distance is fine you'd see scarring on the tire if it was rubbing.

These are the alignment cams:




Basically if any of them are horizontal (the fat part of the cam is horizontal to the bolt) that means its range has been fully used up and the alignment tech probably had to make a compromise somewhere.

 

[eljefe]

Here are mine. So it appears they are used up. How do I get nee ones?

 

[eljefe]

Wouldn’t the cams affect the steering vice what I’m experiencing?

 

[kurek]

. How do I get nee ones?

You don't get new ones, you lower the lift enough that the control arm geometry is within range to achieve correct caster, camber, offset and toe or else you get lift specific control arms that allow correct geometry at your lifted ride height.

My guess is if you had a print out of the alignment for this truck it's probably sitting on too little caster and that's what is giving you that pushing feeling when you steer tightly.

 

[Quick_Shifter]

Wouldn’t the cams affect the steering vice what I’m experiencing?

Rotate you tires and get an alignment. Ask the shop if they can test drive and replicate your feeling. The transfer case may have your truck in all wheel drive too. Sometimes it’s the simple stuff that is over looked

 

[eljefe]

Looks like I’ll start looking for new control arms. Thanks for all the input! Really appreciate it