So I installed my 4" Procomp lift, rancho shocks, extended length end links, brand new rear shackles, new steering gear and pressure & return hose and the truck still drives like complete crap...

When I was getting the front back together I couldn't align the front axle properly and the springs are leaning slightly...

Bumpsteer is terrible, wobbly sounding clunk from front end and she's all over the road.

Do I need an adjustable track bar? I assume the track bar is what's causing my axle to be off center... can I just unbolt it, center axle and re-bolt it?

 

I think there is an excentric bolt you can get for it, I think Christina ran into that on her truck. Also; bump-steer only happens with coil springs.

 

No, it happens with any vehicle with a trac bar. The trac bar and the drag link need to be as parallel as possible to stop bump steer.




Did you put on a drop pitman arm? If yes, get drop brackets for your trac bar.

If not, lengthen your bar, buy a adjustable, or get the cam bolts to make the front axle sit in the right spot again.

You can run without the trac bar, but in my experience it makes the bump steer worse.


I lengthened my own. Slugged it and sleeved it.

 

Nope, that's roll steer;

Bump steer
From Wikipedia, the free encyclopedia

Bump steer or roll steer is the term for the tendency of the wheel of a car to steer as it moves upwards. It is typically measured in degrees of steer per metre of upwards motion or degrees per foot.

On modern cars the front of the tire moves outwards as the suspension is raised, a process known as the front wheels "toeing out". This gives roll understeer. The rear suspension is usually set up to minimise bump steer, where possible.

Typical values are from two to ten degrees per metre, for the front wheels.

Excessive bump steer increases tire wear and makes the vehicle more difficult to handle on rough roads.

Solid axles generally have zero bump steer, but still have roll steer, in most cases. That is, if the wheels move upwards by the same amount, they tend not to steer.

Basics of Bumpsteer As the front wheels move up and down, we want the front wheels to maintain a particular direction. It's most important for the wheels to have minimal bump when we are negotiating the turns. There are certain elements of the construction of the front end components that will make this happen.
The angles of the upper and lower control arms, meaning a line extending through the center of rotation of the ball joints and inner mounts of each arm, intersect at a point we call the instant center (IC). This is one of the components used to determine the moment center location. In order to have near zero bumpsteer, the intended goal, we need to have the tie rods on each side point toward the IC for its side. This is one of two criteria for near zero B/S.

Difference between Bump Steer and Roll Steer[edit]
In a bump steer, both wheels rise together. In roll steer, one wheel rises as the other falls. Typically this produces "toe in" on one wheel, and "toe out" on the other, thus producing a steering effect.

Roll steer is usually measured in degrees of toe per degree of roll, but can also be measured in degrees of toe per metre of wheel travel.

 

Ya ok...... Hit a bump the tires turn a bit. Who cares what it's called. He's trying to fix it, and you told him it doesn't exist with leaf springs, and I(and many others) know that it does bump steer(or what ever you want to call it).

 

I agree, you can call it whatever you want, just being technical.

 

I recently lifted the front almost 6 inches. No issues with bumps and steering. Springs don't lean. I did need to install a $99 Zone Offroad adjustable track bar. Didn't touch the pitman arm.

I could tell I needed the track bar just by eyeing the front diff. I measured it using a tape measure, measuring off a point on the frame to the wheels, not the fenders or tires.

The other obvious indicator was my steering wheel was off center due to the axle being off center. Really easy to adjust/straighten out the steering wheel after you get the diff centered with the adjustable track bar.

My advice:

1. measure the diff and see if its centered. If its not, get an adj tack bar.

2. I would loosen up (just loosen, don't remove) all you front suspension mounting points with the car on the ground, not jacked up. Loosen the front spring mounts, the rear shackles, and the four u-bolts. Then disconnect one of the track bar bolts. Let everything settle with the bolts loosened. Maybe even very carefully and slowly move the car back and forth a few feet.

Then tighten everything back up to torque specs, with the track bar disconnected, and see if your springs straighten out. You most likely won't be able to reconnect the track bar because it'll be too short. At this stage, you could jack up the car off the frame, let the front axle hang at droop and force the old track bar back in place but your diff will once again be off center.

 

Why can't he just adjust the track bar and put it on? Or get a dropped pitman?

 

Yes a 4 inch lift requires a trac bar drop bracket or what i did get the adjustable one, not that expensive, there all over e-bay, and I had to get a dropped pitman arm cause the steering was giving me the death wobble. After the pitman arm problem solved.

 

He needs to get an adjustable one.

But aside from that, I have a theory that he either torqued all the suspension bolts while the car was in the air (its supposed to under its own weight)

or

When he torqued everything down, something was out of alignment because of the short track bar.

Either way, disconnecting the track bar, loosening up all the suspension points, including the ubolts, settling it all out, and re-torqueing with the trackbar disconnected should straighten out his leaf springs and get everything in proper alignment.

 

I'm an idiot and tried to align everything in the air... when it wasn't lining up I used come alongs to get everything to line up and put all the bolts in. I then lowered it hoping it would get into place. It didn't but at that point I was sick of screwing around with it so I tightened everything down anyway and figured it might settle into place after a bit of driving.

Then I realized the problem and came here to confirm. Now I'll fix with adjustable track bar and drop pitman arm.

 

I know but what I am saying is why can't he just adjust it and put in on while it is down?

 

Adjust what?

 

Sounds like you have a handle on it. FWIW I didn't need the pitman arm. You might want to start with an adjustable track bar first and then get the pitman arm if you need to. I've read the pitman arms are a real bear.

BTW, I loosened my trackbar bolts with a socket and breaker bar and used a jack to force the bar up to break it free. I couldn't loosen them under my own power and its pretty hard to get any kind of long bar in there.

 

The adjustable track bar.