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Discussion Starter #1
From the factory, my front camber was an even almost -2 degrees up front and -0.5/-2 in the rear. I've replaced the front control arms with SPC adjustable arms set to -1 deg and have had no issues. In the rear I went with BMR UCA112 (on-car adjustable control arms) set to -0.5 deg. Everything was fine for a few thousand miles but I started hearing a creaking/squeaking/crunching type of noise when pulling in and out of my driveway. The solution from BMR was to put in adjustable upper trailing arms (UTA112) for fear that the factory bushings may be binding up. After installing the UTAs, I noticed when the rear suspension rebounds the rear end lurches to the right. Think of an overpass transition where the pavement isn't completely level, or maybe a dip where a drainage culvert runs under the road. The front compresses and rebounds straight, but the rear compresses straight and the rebound kicks the rear to the side. At high speed (80+) the effect is significant enough to make your stomach get that weird 'floating' feeling. I felt that if I were to hit a similar bump at very high speed I might end up losing control all together. Thinking that there may be a problem with the UTAs, I pulled them off and put the stock arms back on. The sideways motion on rebound is DRAMATICALLY reduced, but not completely gone. BMR says they've never heard of this problem before and their arms are designed to eliminate the flex that causes this type of motion. Does anyone have an idea what might be causing this?
 

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Discussion Starter #3
Would the BMR arms amplify that? The stated rebound difference between stock and BMR is remarkable.
 

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Your rear end should be rock solid with it all aligned. Maybe check to make sure nothing moved out of place.
 

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Discussion Starter #5
I've been under there quite a bit recently. Any advice on particular places to look or common issues? Suggestions for narrowing down the search?
 

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What I experienced in my car was I could feel the cradle moving around ( swaying??) Once I put the BMR cradle lock out kit in I don't notice it or feel it any more . It's definitely "firmer" back there .
I'm wondering in your case if the stiffer arms with stiffer bushings is transferring more load/movement to the stock rubber cradle bushings. Like I said they have a lot of movement in them . I'm just throwing out some ideas .

Sent from my BBF100-2 using Tapatalk
 

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I just put the exact same BMR set up on my Chager. I've had it aligned three times in the last month as the jam nuts were coming loose causing the alignment to be thrown off. Now that it is all aligned again I can notice the passenger rear tire sticking out from the quarter panel while the driver's side rear looks tucked in the rear quarter panel. I was just guessing and thinking maybe my cradle was some how off center. Following this thread
 

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Discussion Starter #8
I just put the exact same BMR set up on my Chager. I've had it aligned three times in the last month as the jam nuts were coming loose causing the alignment to be thrown off. Now that it is all aligned again I can notice the passenger rear tire sticking out from the quarter panel while the driver's side rear looks tucked in the rear quarter panel. I was just guessing and thinking maybe my cradle was some how off center. Following this thread
Yeah, I don't think the alignment techs really torque those nuts down. I always do it myself when I get home from an alignment. Did you do the control arms and upper trailing arms or just control arms? Do you have any weird side-to-side movement on rebound at highway speeds?
 

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I have both the upper trailing and control. I haven't noticed any side-to-side yet but I haven't really driven it too hard since putting the arms on due to the jam nut issue. I will go out here when the rain stops and see if I don't feel it. Do you notice it more in any particular suspension mode or does that seem to matter?
 

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Discussion Starter #10
It's less prevalent in Track mode, I think. It's hard to say for sure because the overall ride is so harsh in Track.
 

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Discussion Starter #13
I've been rolling around in Sport for a while now and it seems to have eliminated the waggle. The stock trailing arms are still in place though. I'll swap back to the BMR arms on my next day off and see what it does.
 

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Discussion Starter #14
I figured it out, for anyone still hunting answers. I got the car realigned again with the stock arms and there was no change in behavior. This time, the shop gave me a few printouts the machine provided. One was describing the installation of substitute Mopar control arms that are 1mm longer or shorter to adjust rear camber and that they would change camber by 0.4-0.7 degrees. Why this was interesting is that the BMR trailing arms were nearly 5/8in different in length from each other. That's almost 16mm! I believe during one of the alignments, the tech mistakenly dialed the trailing arm for camber instead of the control arm and then maxed out the toe bolt. This caused the static numbers on the alignment rack to be green, but when compressed the two wheel hubs would travel in different radius arcs thereby introducing the radial motion in the chassis. I set the trailing arms to the stock arm length, gave the shop specific instructions to NOT adjust them and put in -1 degree using the control arms exclusively. What do you know? All the radial wiggling is gone. Straight up, straight down. All better.
 
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