Pulling right and left during acceleration and deceleration
Thread Starter
JK Freak
Joined: Sep 2011
Posts: 518
Likes: 1
From: Katy, TX
Originally Posted by hneiper
Sounds logical. And I do run a short arm lift so it would tend to lift and settle during ac(de)celeration. But I think they are parallel. Here are a few pics. But I guess maybe you mean when looking at them from the front they should be at same height i.e. same plane At the frame side they start on the same plane but on the axle side the draglink does attach at a lower plane than the track bar.
<img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=383217"/><img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=383219"/><img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=383220"/><img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=383218"/>
I need to take a better picture obviously.
Also, I did some research on what you were saying. And it doesn't have as much to do with how the bars look parallel but rather whether the center of the joints are parallel when measuring them both. Also, it seems important that the length of the track bar and the drag link are as close to matching as possible so that both of the move in the same arc when the suspension is cycling.
And fwiw, I do also have bumpsteer. So it's obvious that they are not exactly parallel and don't move on same axis when suspension cycles.
Thread Starter
JK Freak
Joined: Sep 2011
Posts: 518
Likes: 1
From: Katy, TX
Well, put the arms on yesterday. Seems to have taken care of both the pulling issue and the bump steer (is that even possible?). Anyhow, glad I did it - much better than what I had! Thanks for everyone's suggestions.
JK Enthusiast
Joined: Dec 2011
Posts: 135
Likes: 0
From: Stillwater, MN
This is interesting, as I have the same problem. I'm running evo arms in the front, and all other joints are new in the front end.
Did you replace the rear arms or the front, and any other feedback for me?
TIA!
Sent from my iPad using JK-Forum
Did you replace the rear arms or the front, and any other feedback for me?
TIA!
Sent from my iPad using JK-Forum
JK Enthusiast
Joined: Feb 2015
Posts: 131
Likes: 35
From: United States
When I had the symptoms a couple of months ago it was my rear flanges bent due to heavy 37s. Replaced them and all was better.
Here's a couple of videos of what mine was doing.
http://vid101.photobucket.com/albums/m78/idiutbox/Forum/56A389F9-F8EF-4601-B3B8-1B2BD5589527_zpsy6kcpipr.mp4 http://vid101.photobucket.com/albums/m78/idiutbox/Forum/65A539CB-8822-48D6-AF74-6C5B98B6B63C_zps1niarre0.mp4
Here's a couple of videos of what mine was doing.
http://vid101.photobucket.com/albums/m78/idiutbox/Forum/56A389F9-F8EF-4601-B3B8-1B2BD5589527_zpsy6kcpipr.mp4 http://vid101.photobucket.com/albums/m78/idiutbox/Forum/65A539CB-8822-48D6-AF74-6C5B98B6B63C_zps1niarre0.mp4
JK Newbie
Joined: Oct 2014
Posts: 32
Likes: 0
From: Reno, NV
For folks searching similar issues: I had control arm joint issues 2 times on an LJ I owned. Joints were aftermarket. Both times the control arm joints failed off road, the highway drive home was almost terrifying. I literally could steer the Jeep using only gas and braking. Jeep was all over the road. It was an obvious sudden failure issue and not a long term wear issue.
The first time it happened the lift was less than 1 year old on a weekend warrior vehicle. I spent a lot of time looking, narrowing down, and finally finding the problem. I started removing 1 control arm at a time to find the broken joint. It is very difficult to check joint condition when they are mounted.
I prefer bushings rather than joints.
The first time it happened the lift was less than 1 year old on a weekend warrior vehicle. I spent a lot of time looking, narrowing down, and finally finding the problem. I started removing 1 control arm at a time to find the broken joint. It is very difficult to check joint condition when they are mounted.
I prefer bushings rather than joints.
JK Jedi
Joined: Oct 2010
Posts: 6,222
Likes: 376
From: Southwest Reno, NV
Axle shift during articulation can cause the pulling to one side. When you accelerate it causes a weight shift from the front of the vehicle to the rear (squat) that is absorbed into the arms or is transferred to the coils. The location of the mounts on the axle and frame will dictate the amount of force applied to the coils and some will use the term anti squat given as a percentage of force being applied.
That being said, the coils will compress in the rear and cause a rise in the front coils as they unload the weight to the rear. When the rear coils compress and the front extend the track bars will pull the axles to one side, this case being the right, it will cause a pull in the steering. At 4" of lift and keeping the stock mounting locations on the track bar you will amplify this movement in the axle. By doing a drag link flip and raising the rear bracket to get the rear track bar as flat as possible will nearly eliminate this pulling affect due to acceleration and will eliminate the bump steer. You will also raise the roll center of the jeep making it more stable in off camber situations and in high speed cornering. The opposite effect can be had during braking as you reverse the weight shift back to the front and the jeep will pull in the other direction.
Of course the stiffness of your coils and the compression rates of your shocks will affect the amount of compression the coils will take.
Hope this is understandable and helps.
That being said, the coils will compress in the rear and cause a rise in the front coils as they unload the weight to the rear. When the rear coils compress and the front extend the track bars will pull the axles to one side, this case being the right, it will cause a pull in the steering. At 4" of lift and keeping the stock mounting locations on the track bar you will amplify this movement in the axle. By doing a drag link flip and raising the rear bracket to get the rear track bar as flat as possible will nearly eliminate this pulling affect due to acceleration and will eliminate the bump steer. You will also raise the roll center of the jeep making it more stable in off camber situations and in high speed cornering. The opposite effect can be had during braking as you reverse the weight shift back to the front and the jeep will pull in the other direction.
Of course the stiffness of your coils and the compression rates of your shocks will affect the amount of compression the coils will take.
Hope this is understandable and helps.
