Centering Axle By Adjusting Control Arms

[XCRN]

I vaguely remember reading something about using adjustable control arms to help center the axle and I got to thinking every time I need to remove the trackbars, it is a huge PITA to re-install them. So I am wondering if my control arms are adjusted in a manner that is causing a bind when centered with the track bar at ride height. Every time I go to install I need to use a lot of force, especially the rear where I have broken a few 1in wide ratchet straps and got a 3in wide ratchet strap specifically to center the rear. I usually need to pull the front about 3/8" and the rear 1-1/4". Is there something to using the adjustability of my control arms to help center the axle so installing the track bar is easier and causing less bind when at ride height? I have double adjustable control arms all around and adjustable trackbars front and rear that are adjusted to center.

 

[mjonesjr84]

Nothing in your control arms will center the axle. That is the sole purpose of the trackbar. The easiest way to center up the axles is to have the vehicle on its own weight, then use the ratchet strap. I use a 1.5" strap Everytime with ease.

 

[MutantNinjaTJ]

You are asking about an adjustable track bar not adjustable control arms.

 

[freedom_in_4low]

I vaguely remember reading something about using adjustable control arms to help center the axle and I got to thinking every time I need to remove the trackbars, it is a huge PITA to re-install them. So I am wondering if my control arms are adjusted in a manner that is causing a bind when centered with the track bar at ride height. Every time I go to install I need to use a lot of force, especially the rear where I have broken a few 1in wide ratchet straps and got a 3in wide ratchet strap specifically to center the rear. I usually need to pull the front about 3/8" and the rear 1-1/4". Is there something to using the adjustability of my control arms to help center the axle so installing the track bar is easier and causing less bind when at ride height? I have double adjustable control arms all around and adjustable trackbars front and rear that are adjusted to center.

You are correct. The upper control arms have enough triangulation that they will locate the axle side to side when static. You can lengthen one while shortening the other to bring the chassis over and line up your track bar bolt so it slips in. I like to keep an angle finder stuck to the pumpkin so I can see the pinion angle, because if you lengthen one faster or slower than the one you're shortening, it will raise or lower the pinion.

Anybody using ratchet straps to get their TB installed is driving around with their links in a bind.

 

[srimes]

I vaguely remember reading something about using adjustable control arms to help center the axle and I got to thinking every time I need to remove the trackbars, it is a huge PITA to re-install them. So I am wondering if my control arms are adjusted in a manner that is causing a bind when centered with the track bar at ride height. Every time I go to install I need to use a lot of force, especially the rear where I have broken a few 1in wide ratchet straps and got a 3in wide ratchet strap specifically to center the rear. I usually need to pull the front about 3/8" and the rear 1-1/4". Is there something to using the adjustability of my control arms to help center the axle so installing the track bar is easier and causing less bind when at ride height? I have double adjustable control arms all around and adjustable trackbars front and rear that are adjusted to center.

Yes, the control arms have a little bit of triangulation that tries to center the axle and will fight the track bar. The track bar wins as that's it's job.

Part of getting the control arms dialed in is minimizing bind at ride-height. One of the advantages of the savvy aluminum arms is how easy they are to adjust and minimize bind.

When reinstalling the track bar I found it helps to jack the axle up and down to help get it lined up.

 

[Rickyd]

You are correct. The upper control arms have enough triangulation that they will locate the axle side to side when static. You can lengthen one while shortening the other to bring the chassis over and line up your track bar bolt so it slips in. I like to keep an angle finder stuck to the pumpkin so I can see the pinion angle, because if you lengthen one faster or slower than the one you're shortening, it will raise or lower the pinion.

Anybody using ratchet straps to get their TB installed is driving around with their links in a bind.

While that is true I'd add that you want to have the axle centered in reference to the frame,then set trackbar to hold it there and last adjust the arms to not be bound up and make the axles perpendicular to the centerline

 

[freedom_in_4low]

Nothing in your control arms will center the axle. That is the sole purpose of the trackbar. The easiest way to center up the axles is to have the vehicle on its own weight, then use the ratchet strap. I use a 1.5" strap Everytime with ease.

You need to refresh your geometry.

 

[mjonesjr84]

You need to refresh your geometry.

The control arms themselves will not center the axle to dead center. Your axle should get centered and then adjust your arms to match where the axle location is.

 

[freedom_in_4low]

While that is true I'd add that you want to have the axle centered in reference to the frame,then set trackbar to hold it there and last adjust the arms to not be bound up

What I do is use the UCAs to center the frame over the axle and then set my track bar so the bolt slips in. My first post was on the assumption that the OPs track bar is already set to center the axle and he's just removing and installing for other reasons. He could just remove a UCA, connect the bar and then adjust the removed UCA until its bolt slips in but his pinion angle may drift a bit.

 

[XCRN]

What I do is use the UCAs to center the frame over the axle and then set my track bar so the bolt slips in. My first post was on the assumption that the OPs track bar is already set to center the axle and he's just removing and installing for other reasons. He could just remove a UCA, connect the bar and then adjust the removed UCA until its bolt slips in but his pinion angle may drift a bit.

Thats what I was having to do to install the track bar in the rear was removing control arms and unadjusting them until they fit then readjust back to length. So I should leave the LCA alone assuming they are squared correctly and adjust UCA small increments at a time until my pre-set track bar can be installed without force?

 

[jjvw]

Thats what I was having to do to install the track bar in the rear was removing control arms and unadjusting them until they fit then readjust back to length. So I should leave the LCA alone assuming they are squared correctly and adjust UCA small increments at a time until my pre-set track bar can be installed without force?

At the end of the day at ride height, none of the adjustable control arms or the adjustable track bar are in bind when the lengths are correct. Each bolt can be removed by hand after loosening.

 

[XCRN]

At the end of the day at ride height, none of the adjustable control arms or the adjustable track bar are in bind when the lengths are correct. Each bolt can be removed by hand after loosening.

Makes sense. Ill probably over the winter re-adjust it all to where the bolts slide in.

 

[jrfuda]

This thread was super helpful to me yesterday. I've been swapping out the pieces of the RC 4" lift the PO installed 3-4 years ago (I'm replacing everything but the springs since they've not sagged at all). I was having trouble getting the rear axle centered after replacing the shocks, non-adjustable trackbar, and control arms with new shocks, an adjustable trackbar, and double adjustable control arms. My ratchet strap had done all it could do. I started adjusting the upper control arms until I had the axle centered with none of the components in a bind. I kept an angle finder on the diff all the while to ensure the pinion angle stayed constant while I did all this. I do not think I would have ever gotten the axle centered without adjusting the upper control arms.

I'll be doing this all again over the next week or so, working for about 90 minutes each morning before work (I'm really slow too), as my Savvy UA is finally getting delivered tomorrow and I'll have to tweak everything again when I set pinion angle (and will have to wait for my DCDS to be delivered). BL and MML already complete.

I've owned the LJ since October. I think the PO's lift really messed with the alignment of the rear end. The current spare used to be the DS rear tire, and it is completely bald whereas the other tires still have about 50% of their tread (well, except the current DS rear which was the former spare and was apparently never rotated as it is brand new).

 

[mjonesjr84]

after replacing the non-adjustable trackbar

I think the PO's lift really messed with the alignment of the rear end.

The first statement there is the reason for the second one.

 

[AndyG]

Once you get one dialed you will notice the planted, smooth feel. For lack of a of a better word vehicle will feel very coordinated.