Wobble diagnostics
06-22-2016, 06:49 PM
#1
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Wobble diagnostics
I"ve been getting a some front end wobble and started running PlanMan's Death Wobble checklist to try to check things out. I've posted some images and videos in the hope of getting some feedback as to whether anyone thinks the results are significant (e.g. yep, that bushing is bad). Any feedback would be appreciated.
When I rotated the steering wheel back and forth quickly I felt a bit of motion on the trackbar (it's a RockKrawler adjustable, part of my 2.5" RK lift). Sorry no video of it. But I pulled the trackbar off to examine the mount holes. The two pictures below are of the axle mount hole and the chassis mount hole. They don't appear to be wallowed out but I'd be interested in a second opinion.
Next I tested the drag link bushing and the tie rod bushings by compressing them vertically with a pair of channel locks. I definitely saw some vertical motion (about 1-2 mm) on both. I'm not sure whether this is significant or normal. I've included two videos, one compressing the drag link bushing and then the tie rod bushing, the second is a better shot of the tie rod. My apologies in advance for the sideways view and shakiness!
https://youtu.be/r_cP8i5kd5w https://youtu.be/pwi0zBuceEs I plan on running the rest of the checklist tomorrow, but wanted to get some feedback on these results. Thanks!
When I rotated the steering wheel back and forth quickly I felt a bit of motion on the trackbar (it's a RockKrawler adjustable, part of my 2.5" RK lift). Sorry no video of it. But I pulled the trackbar off to examine the mount holes. The two pictures below are of the axle mount hole and the chassis mount hole. They don't appear to be wallowed out but I'd be interested in a second opinion.
Next I tested the drag link bushing and the tie rod bushings by compressing them vertically with a pair of channel locks. I definitely saw some vertical motion (about 1-2 mm) on both. I'm not sure whether this is significant or normal. I've included two videos, one compressing the drag link bushing and then the tie rod bushing, the second is a better shot of the tie rod. My apologies in advance for the sideways view and shakiness!
https://youtu.be/r_cP8i5kd5w https://youtu.be/pwi0zBuceEs I plan on running the rest of the checklist tomorrow, but wanted to get some feedback on these results. Thanks!
06-23-2016, 11:05 AM
#3
JK Jedi
06-23-2016, 09:49 PM
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Heim joint seems ok. No play in it. I think I'm going to have to reattach the track bar and do the steering wheel test again to duplicate the motion that I saw on it.
Any thoughts on the drag link and tie rod bushings? Is the vertical motion I'm seeing a "normal" amount? I may have to bring my channel locks to work and crawl under my buddy's newer jeep to figure out what "normal" is.
Any thoughts on the drag link and tie rod bushings? Is the vertical motion I'm seeing a "normal" amount? I may have to bring my channel locks to work and crawl under my buddy's newer jeep to figure out what "normal" is.
06-24-2016, 02:17 AM
#6
Super Moderator
I"ve been getting a some front end wobble and started running PlanMan's Death Wobble checklist to try to check things out. I've posted some images and videos in the hope of getting some feedback as to whether anyone thinks the results are significant (e.g. yep, that bushing is bad). Any feedback would be appreciated. When I rotated the steering wheel back and forth quickly I felt a bit of motion on the trackbar (it's a RockKrawler adjustable, part of my 2.5" RK lift). Sorry no video of it. But I pulled the trackbar off to examine the mount holes. The two pictures below are of the axle mount hole and the chassis mount hole. They don't appear to be wallowed out but I'd be interested in a second opinion. <img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=650446"/><img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=650447"/> Next I tested the drag link bushing and the tie rod bushings by compressing them vertically with a pair of channel locks. I definitely saw some vertical motion (about 1-2 mm) on both. I'm not sure whether this is significant or normal. I've included two videos, one compressing the drag link bushing and then the tie rod bushing, the second is a better shot of the tie rod. My apologies in advance for the sideways view and shakiness! Video Link: https://youtu.be/r_cP8i5kd5w Video Link: https://youtu.be/pwi0zBuceEs I plan on running the rest of the checklist tomorrow, but wanted to get some feedback on these results. Thanks!
First - does the wobble come and how with speed changes? There is a difference between bump steer and DW. When my stock steering stabilizer finally gave up the would feel every little bump in the road rand would feel it in the steering wheel.
Second - have you recently been off-road or in the mud? I ask because you could have thrown a wheel weight or have some mud caked on the inside of the wheels.
Third - I had the RK affront track bar and the axle heim joint had the slightest play and it was caused my case of DW. I hit a change in pavement height and had a case of DW as bad that I had to stop Andy regroup and eventually change my shorts. If you are in doubt about the RK heim change it. That is one less thing towery about.
9 times out of 10 DW is caused by the front track bar.
Good luck
R/
Will
06-24-2016, 03:27 AM
#7
JK Junkie
Make sure that bolt is a 9/16" as well.
Putting the slightly larger bolt was the difference for me. Had wobbles about 40 mph and was consistent. Removed both bolts and replaced, not an issue since, been awhile too.
Also, maybe just me being full of hate, but heim joints suck. They are noisy, cheap, and usually on the axle end which is taking a good amount of deflection and force. My first track bar had the same problem. You could watch the joint move on the bolt.
Putting the slightly larger bolt was the difference for me. Had wobbles about 40 mph and was consistent. Removed both bolts and replaced, not an issue since, been awhile too.
Also, maybe just me being full of hate, but heim joints suck. They are noisy, cheap, and usually on the axle end which is taking a good amount of deflection and force. My first track bar had the same problem. You could watch the joint move on the bolt.
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06-24-2016, 05:48 AM
#8
JK Jedi
Make sure that bolt is a 9/16" as well.
Putting the slightly larger bolt was the difference for me. Had wobbles about 40 mph and was consistent. Removed both bolts and replaced, not an issue since, been awhile too.
Also, maybe just me being full of hate, but heim joints suck. They are noisy, cheap, and usually on the axle end which is taking a good amount of deflection and force. My first track bar had the same problem. You could watch the joint move on the bolt.
Putting the slightly larger bolt was the difference for me. Had wobbles about 40 mph and was consistent. Removed both bolts and replaced, not an issue since, been awhile too.
Also, maybe just me being full of hate, but heim joints suck. They are noisy, cheap, and usually on the axle end which is taking a good amount of deflection and force. My first track bar had the same problem. You could watch the joint move on the bolt.
06-24-2016, 06:29 AM
#10
JK Jedi