I am figuring out an issue where my car pulls left on acceleration and right on deceleration. Here’s what my mechanic believes to be the problem. I have core 4x4 control arms with Johnny joints on 1 end and rubber bushings on the other.
Is this normal?
- Thread starter Jwhite
- Start date
i don't see any side to side pulling from that video. I do see a bit of axle wrap as you accelerate and decelerate. The first thing i would do is make sure all 4 of your control arm bolts (uppers and lowers) are tight. It looks like there is play in that control arm which might be because the bolts are not tight or the bushing is worn out.
OP
Do I use stock torque specs? Control arms are a year old with less than 10k miles so hard to Believe they are broken already. I would imagine some play is normal because of the Johnny joints?
KennethS
TJ Enthusiast
Mine had a similar issue with pulling to the side during acceleration and deceleration. I found it was caused by the front axle, specifically the rubber bushings in the aftermarket adjustable lower control arms. The bushings were very sloppy and replacing them resolved the problem.
The johnny joints will give you rotational movement but should not move fore/aft in the control arm mount. In that video it looks like the control arm is moving due to a loose bolt. If your mechanic took that video or its at your mechanic just have them make sure all 16 of the control arm bolts on ALL of your uppers and lowers are tight then go drive the jeep and see if it helps.
OP
bolts are tight. I didn’t see and side movement with the axle only rotational so I wonder if his diagnosis is incorrect? Could it be something inside of the differential causing this?
The only thing i can think of that would cause that if your bolts are all good and tight is the rubber bushings. Are they push-in bushings that go in from the left and right with a steel sleeve or are the rubber bushings galvanized and hard molded to the end of the control arm?
Nothing inside the differential would cause that movement.
Nothing inside the differential would cause that movement.
OP
They have those metal sleeves. Let me rephrase my last question, could something inside my differential be causing a pull left on acceleration and right on deceleration? When I changed the fluid at 70k miles a glitterly glob of diff fluid came out first which I found concerning. It was much more than just some shavings on the magnet.
If something in the differential could cause that i have never had that problem so i can't speak intelligently to it. If you had lots of glitter that was more than shavings on the drain plug then maybe the cross shaft that goes through the spider gears might be wallered out. Loose ring gear bolts, shim problems...but i'd think if anything like that was going on you'd be able to hear a whining noise. Maybe some others can chime in with any potential issue with the diff that might cause the pulling but i doubt it. I'm still leaning towards rubber control arm bushings.
Make sure your Track Bar bolts are tight also.
Make sure your Track Bar bolts are tight also.
OP
Quick update I emailed back and forth with core 4x4 and they admitted they stopped using rubber bushings due to quality control issues. Now the question is do I replace them with polyurethane bushings or replace all the control arms with rockjocks?
You said that one end of your control arms are Johnny Joints and the other end is the rubber bushing. Its been my experience that if you want to go from rubber bushing to polyurethane that you have to literally torch the rubber bushing out of the end because its molded to that end of the joint. Then once you identified the ID of that end you could probably put in Poly Bushings. However, normally poly bushings push in from both sides with a sleeve and usually the control arm will have a grease zerk so you can keep the bushing lubricated. Since you don't have that it might be better just to replace the control arms altogether although at a highercost. Consult with Core 4x4 and see what they suggest. (This is assuming that your existing rubber bushings need replacing and are the actual cause of your current issue).
OP
KennethS
TJ Enthusiast
What steering setup do you have? Post a pic of your front axle. Left on accel, and right on decel makes the steering suspect… as Jeep accels, it lifts front pulling drag link to left. Decel pushes front down, pushing drag link right…
Yeah, you have bad bushings, but I thing you’re chasing the wrong rabbit for the steering issue…
Yeah, you have bad bushings, but I thing you’re chasing the wrong rabbit for the steering issue…
OP
I had stock steering and then upgraded to currie but I have the same issue with both. I have a 2.5 inch lift. I am not using any track bar relocation brackets or dropped pitman arms.
KennethS
TJ Enthusiast
If the axle shifts left or right, how can that not change the direction of travel?
OP
I’m 99 percent sure it’s unrelated to steering. Do you think having the control arms set to unequal lengths left to right is what likely killed those bushings? I had 2 shops screw up the 8 arm alignments and at one point the control arms were like 5 whole turns different from the other side. I obviously fixed that issue and now all control arms are set to where they need to be.
Having control arms at different lengths could absolutely kill your bushings. Its putting lateral stress on the rubber. The best way to get them the same is have both uppers or both lowers side by side and run a bolt through both ends to make sure they are the same length. At this point i would think that simply unbolting the rubber bushing end of the control arm and visually inspecting for cracks or rotting would be the next step. Hard to tell when its mounted where you can't see it.
OP
All control arms are equal now because I did a 10 arm alignment along with the technician. When I first got the lift installed by the Jeep dealer they set everything unequal. And after that a 4x4 shop screwed it up again. Do you think the video proves the bushing is shot? I really don’t want to remove that bolt twice. You can see that the bolt is moving around inside of the bushing.
Grab a tonka car (or any other that has solid axles) and shift the axles side to side... should not affect the travel direction at all. The only thing that will is either axle not perpendicular to the centerline of the vehicle, or the steering.
Now, maybe one or both of the OP's axles are shifting only on one side to steer the Jeep, but that would be the only option to steer it.
OP, once you get the bushings sorted, if it is still doing the same issue, do your steering tests (dry, under power, one side on ramp) to see what is causing the issue.