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Bushing Shift

- - - - - Rear UCA Bushing

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#1
ChrisA

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Has anyone had the control arms shift on the bushings? My Right Rear Upper Control Arm has slid forward to the point of touching the mounting brackets. The Left side has moved a slight bit from being centered. This has happened before, but not so sever and I pulled the arms and reentered them with a large C-clamp. Should I order new bushings, these are only a few years old? Or glue these in place with something like weather strip adhesive? 

Right Rear UCA

 

 


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#2
Tom Sager

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Has anyone had the control arms shift on the bushings? My Right Rear Upper Control Arm has slid forward to the point of touching the mounting brackets. The Left side has moved a slight bit from being centered. This has happened before, but not so sever and I pulled the arms and reentered them with a large C-clamp. Should I order new bushings, these are only a few years old? Or glue these in place with something like weather strip adhesive? 

 

 

 

 

I had the same thing on my car recently.  Bushings are probably worn out.  You could also have a bent spindle or bent upper or lower control arm which contributes to the shift.  Also check the upper knuckle bushing as that one seems to get sloppy more often.  A bent subframe could also contribute.  Sorry this doesn't narrow things down much but it would be wise to get the whole corner apart and have everything checked. 


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#3
Steve Scheifler

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Unfortunately, if they can move in the arm they may also rotate in the arm. Not rotate freely but “pop” under ubrupt max load then stick again. Same with the outer one before it gets really loose. I suspect this is one of the things contributing to inconsistent/changing cross weights and “settling” that people experience, especially if they are not originally tightened with the car loaded (or the arm held in that position) rather than in droop.

Keep in mind when looking at them closely or when removing/replacing them, with the rear set for toe-in using the lower arms, the upper bushings are all in a slight bind as a result. That may be mistaken for something bent when it isn’t, and can add to them moving a given direction when loose.
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#4
ChrisA

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The car is straight, no contact or offs to give me concern. I think these bushings are just not snug enough in the arms for some reason. When I adjusted them with the C-clamp it did not take much hand force to move them. I think I may just order another set of the rear upper bushings. I always make my practice to tighten all the suspension bolts with the car on hub stands. And I have had some issues chasing cross weight, perhaps these buggers were the culprit.


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#5
davew

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Change the bushings and you will be fine. These bushing seem to be the most prone to wear. I figure 2-3 year lifespan depending upon how often you race.

 

Dave


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#6
Guest_JNJ_*

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Pull the long bolt on the lower arm, if you can't easily slide it back in, the lower arm is bent.  A bent lower arm will make the upper arm be in a bind, as it move the bushing will shift.  Usually the bushing in the knuckle will not be centered but it isn't in the picture.  After you have seen it a few times, you can spot it by the clearance between the bush in the knuckle and the upper arm.



#7
Steve Scheifler

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Actually, at least as often as not, when the long bolt won’t slide in & out it is the bolt itself that has bent. If it gets hit hard you can see everything wobble as you rotate it slowly, changing toe and camber slightly.
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#8
davew

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I buy long bolts by the dozen from Mazda. We loosen the nut and rotate the bolt while watching the rotor. If it moves the bolt is bent, replace. We now have the complete set of jigs  https://www.advanced...igs-deluxe-kit 

 

to see if your suspension parts are bent.

 

The 8c0c bushings are the most common to go bad


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Building Championship winning cars since 1995

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#9
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Things get a little bit rough here out west, I wished I had saved the rear lower arrms that a new bolt won't slide through.  I really wished I had never had to replace one but that would take another thread.     They shift the upper arm bushing and the upper knuckle bushing.  I did miss the part about a new bolt even though I always rotate it, any they do bend more often than the lower arm the arms do bend.  If the new bolt won't go in the lower arm, it is bent.  The misalignment causes the knuckle to rotate while being viewed from the side.  This makes the upper arm to shift accordingly.  I am Chassis Engineer at a major OE and have a lot of SM experience and running up front.  We stock the long bolt and have given as many away at the races as I have used.  Most the time it is all that is needed.  BTW, I stock lower arms too.  Hope this helps resolving your issue.






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