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Discussion Starter #1
Ok, I have had this problem since day one of the car (03 GT Auto stock) clunk coming from the rear. I was told by a repair shop it was the rear upper and lower control arms. So, I replaced them with UPR control arms. It was still doing it. Then was told it was the rear end. Had it rebuilt and then was told the transmission. So, I though I would take it to the experts, Ford. Ford said it was the rear end. I told them that it was just rebuilt. They still beleived it was the rear end. So, I let them look at it and $200 later they said it was fine every thing was tight and in specs. Then they said it was the tranny. I took to another place to have the tranny rebuilt and a new TC. Its was still doing it. Oh, and I also had the tranny mount, u-joints, and drive shaft replaced. The guy at the tranny shop (who I trust) said he knows a guy at ford who is really good with this and they went on a test drive and he said it was the after market control arms that I had put on. Now what is happening is that when I am accelerating normaly and get to 35-50 and then let off the gas it jerks foward then back and thats when you hear the clunk. My ? is can it be the computer thats causing the jerking or some kind of sensor?
 

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Head Unicorn
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No. Not at all. Computers don't cause clunks.

The bolt holes on the chassis side mount have probably become ovaled somewhat and are allowing the bolts to move slightly. Reinforce the bolt holes. Done.
 

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Discussion Starter #3
No. Not at all. Computers don't cause clunks.

The bolt holes on the chassis side mount have probably become ovaled somewhat and are allowing the bolts to move slightly. Reinforce the bolt holes. Done.
Yea, I know that the computers don't cause a clunk. I was wondering if the computer could be causing the jerking. So, where are these bolt holes and how do I reinforce them?
 

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Watch n learn
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Can a computer cause a jerking? Ya, but so could a TON of other things. The holes would be where the control arms mount to the frame. Could also be a torn torque box, **** I feel bad for ya dude, al, that money at a bunch of different shops and its the same. I'd be losing my damn mind.
 

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No. Not at all. Computers don't cause clunks.
They do if you drop them. :bubba:

When you replaced the arms, was the suspension loaded or hanging in the air when you torqued the control arm bolts? If the suspension was hanging free, the bushings are probably binding.

As far as the bolt holes being elongated, thats also a possibility. You will have to remove the control arms from the chassis side to look at the bolt holes. Take the bolts and see if they have any slop. Im not sure about the jerking. Maybe the fuel pump is going out or something with the trans? Could just need a simple tuneup.
 

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Discussion Starter #6
Can a computer cause a jerking? Ya, but so could a TON of other things. The holes would be where the control arms mount to the frame. Could also be a torn torque box, **** I feel bad for ya dude, al, that money at a bunch of different shops and its the same. I'd be losing my damn mind.
Yea, I am going nuts. My wife is really good about though she says lets just find and fix it and I am ready to blow it up.
 

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Discussion Starter #7
They do if you drop them. :bubba:

When you replaced the arms, was the suspension loaded or hanging in the air when you torqued the control arm bolts? If the suspension was hanging free, the bushings are probably binding.

As far as the bolt holes being elongated, thats also a possibility. You will have to remove the control arms from the chassis side to look at the bolt holes. Take the bolts and see if they have any slop. Im not sure about the jerking. Maybe the fuel pump is going out or something with the trans? Could just need a simple tuneup.
I think it was up on the lift when they did it.
 

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Head Unicorn
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With the car supported on its tires, raised off the ground (on an open center trailer, drive on lift or heavy duty ramps) lay under the rear end and have somebody forcefully rock the rear of the car left and right. If it's in the suspension mounting points you'll hear and see the movement and be able to easily identify the problem. If the holes have become elongated simply remove the arm from that point and weld a re-inforcement plate over that mounting point.
 

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Watch n learn
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Yea, I am going nuts. My wife is really good about though she says lets just find and fix it and I am ready to blow it up.
Have you had it at a suspension shop? Might be worthwhile as they'd specialize in this kind of thing. We often have cars come in for just this and it tough to find at home, need a drive on lift and at least one other strong person to simulate the conditions.
 
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