Progress Thread "12th Owner": My '93 Notchback Progress Thread

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Habu135

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I'm out of ideas as to why my car sits 3/4" higher in the right rear as compared to the left rear so I've decided to bring it to a local collision center for a visual inspection and possibly a frame straightening. This is the logical next step before dropping $5k on paint and body. More to follow.......
 

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Davedacarpainter

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I'm out of ideas as to why my car sits 3/4" higher in the right rear as compared to the left rear so I've decided to bring it to a local collision center for a visual inspection and possibly a frame straightening. This is the logical next step before dropping $5k on paint and body. More to follow.......
Yeah, i bet your frame is twisted a bit. It’s remarkably easy with our mustangs.
 

Mustang5L5

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For what it’s worth, I had a conversation with MM that basically stated that it’s rare to see any fox sit perfectly level on all 4 corners. One corner will always be off.

However, yours seems way off. Have you tried rotating the springs slightly. Front opposite corner spring may be off slightly

That’s why they recommend welding the SFCs with weight in the tires, vs a 4-pt lift.

Also...I’m liking 17” pony wheels more and more these days
 
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Habu135

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Ya, the 17" Ponys are nice.

Regarding the height, all my suspension is new to include the LCAs and UCAs. The height difference is consistent with a full tank or not. I removed the spring isolators and have ensured the spring pig tails are correct and that the shocks are correct. Everything seems complete so the only remaining thing is to bring it to a collision shop to test and measure the frame.
 

Habu135

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Yes, handles the same left to right. No obvious body panel gaps and the car tracks straight. I even went so far as to triple check the MM panhard bar installation as it sits high on the right. I realize that that may not be related to a bent frame, but it's evidence of something.
Screenshot_20190910-193320_Gallery.jpg
 

Habu135

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So I brought my car to a local collision center today and they advised me that my car's frame is not twisted. They suggested that the side to side height imbalance may be from the suspension components. So I'll be taking the rear springs and shocks out this weekend and comparing them to each other. I've never heard of this, but suspect one loaded spring or loaded shock could be different in height than the other. This seems highly unlikely, but possible. Any thoughts?
 

Rdub6

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I could be way off, but if you think it’s suspension, I would try to get their length while loaded on the car. Maybe one is “softer” having wore out faster, causing it to compress further. I would think they will likely return to original, similar lengths unweighted.
 

Habu135

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It looks more and more that the springs are to blame for the height imbalance issue. I have both installed with the pig tails at 6 o'clock, but now MM is advising me that the springs should be pointed to the left. Does anyone have any experience with this or even adjusting the height by turning/installing one spring differently then the other?
 

Habu135

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I'm still trying to chase down my suspension bug (why the right rear sits higher than the left rear). Here is Maximum Motorsports' advise to me:

I would jack the car up, loosen both locknuts at the end of the PHB rod. Remember, the one with notches machined on the OD is a left hand thread nut. Back both nuts off several turns. Put the car on level ground. Spin the PHB rod by hand CW then CCW, until you find the place where it turns the easiest. This is the point at which the rod’s length is correctly set to match the geometry of the rear suspension. Jack the car up and torque the locknuts. These will eliminate any possibility of the PHB jacking one side of the car up. It can do this, but only if there is a lot of preload on it.

For any of the control arms which have rubber bushings installed in them, you do need to make sure that the bolts were tightened when the suspension was at ride height. You can do this in the rear by putting jack stands under the rear axle. The FCA bolts need to be down with the car on a drive on lift. If you tighten these bolts with the suspension not at ride height, the rubber bushings will either raise or lower the ride height at that corner of the car as they are torsional springs.

For the rear springs, the end of the coils should point to the left. This is the same things as saying that the end of the coils should be located in the 6 o’clock position when viewed from the top.

To reduce the ride height, you could try clocking the rear springs to the 9 o’clock position. Do not try to cut the rear springs. If you do this, they will no longer fit properly. You can clock the springs differently from side to side.

When you pull the springs out to compare them, remove all isolators, put the springs with the ground end (top) down and set them side by side so that the open end (bottom) of the springs are nearest to each other. That will make it easy to very accurately compare their free lengths.

When you put the springs back in the car, I would swap them from side to side.

On one car, I have seen the box which is above the rear upper spring perch was collapsed. This caused the ride height on one side to be reduced. If this is happening on your car, it would be the LR upper spring perch.