Different Lenght A Arms?

Discussion in 'Fox 5.0 Mustang Tech' started by Farrell5.0, Mar 30, 2014.


  1. Farrell5.0

    Farrell5.0 Not sure what "DP" means, but know's he likes it!

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    When I put a 9" wheel in the front, I noticed really bad rubbing on the driver's side. Under minimal turning, braking, etc. I checked the fender height between both sides and the driver's side was .25" lower so I put some rubber spacing under the spring so that both sides were even. I hadn't had any sort of rubbing at all on the passenger side, under full lock, hard turning or anything so I was surprised that .25" made that much of a difference. After adding some spacing, it still rubbed quite a bit, although not as bad. After closer examination, the driver side actually sticks out at least .25" further on the driver's side. I know its not the wheels because both are the same distance to the strut. Is it possible the stock A arm is longer on the one side? Or is this caused by alignment? I can't find anyone else with this issue. Any ideas?
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  2. tonydalrymple

    tonydalrymple Active Member

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    This is a tough one, since it'll take allot of exacting measurements to confirm the real problem. The easiest would be to take it to a chassis\frame shop with the latest laser pinpoint measuring capabilities. Comparing thier measurements to the factory manual; they could determine if the chassis, engine cross member, or something else is tweaked. The less costly method would be putting the car up as level as possible on four jack stands & taking allot of accurate measurements yourself. Enticing a friend with beer & pizza would be wise.... oh, & save the beer until after taking measurements.... ;)
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  3. 84Ttop

    84Ttop They make new pistons every day, so why worry? SN Certified Technician Mod Dude

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    It's doubtful that the stock control arms are different lengths. It is possible that something is bent or simply out of alignment. My first stop would be to the alignment shop and have them see where everything is. A good alignment shop will tell you if you're heading to the frame shop or have a bunch of twisted up parts.
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  4. Farrell5.0

    Farrell5.0 Not sure what "DP" means, but know's he likes it!

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    I suppose I'll have to take it to the alignment shop. It drives straight though and probably only has a couple thousand miles since the last alignment. The chassis only has 78k miles. It makes good power now but I have proper chassis stiffening and no drag launches. And even still it's only been making said power since a little after the last alignment.
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  5. MFE92

    MFE92 Active Member

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    Welcome to what passed for "precision" in the assembly of the foxbody mustang. Totally normal for these cars, it's just that most people never look close enough to notice. For ****s and giggles, find the exact center of the K-member by stringing an "X" between the A-arm pickup points, drop a plumb bob from the center of the X, and mark the floor. Drop the plumb bob under the center of each balljoint, and mark the floor there too. Measure the distance from center to balljoint on each side. That will eliminate any question about whether or not the A-arms are the same length. And they will be, because the various A-arms are more than 1/4 inch different in length.
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  6. Farrell5.0

    Farrell5.0 Not sure what "DP" means, but know's he likes it!

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    I figured it was a flaw in the super high tech chassis. I'll have to try this.
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  7. 7991LXnSHO

    7991LXnSHO Active Member

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    In an 87 Cougar, I hit a big pot hole while in traffic and a slush storm. It bent the rim AND messed things up badly enough that it took a good frame shop to fix the alignment. They moved the strut tower brace and gosh knows what below too.
    My point is, you may have the victim of a solid curb check.
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  8. revhead347

    revhead347 I have face herpes.

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    I hate to say it, but I'm with MFE. It's just not that much of a precision built car. Most Mustangs are a quarter inch off on the wheelbase from side to side too.

    Kurt
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