#21  
Old 01-15-2022, 12:51 PM
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If those coil overs attach to the same mounting point as the OEM shocks, I'd guess that the crossmember is broken and the shock is making it's way towards the trunk floor.

That mounting point was never engineered to hold up the weight of the car, only to dampen bounce that the shocks job is to stop. Since I've repaired a few shock mounts on A bodies broken from air shock usage, I've been curious how long coil overs would take to break that upper mount.

I'd be looking at that upper mount to see if the coil over has broken it. I hope that I'm wrong, because welding that mount back together after it's broken, while in the car, isn't a walk in the park.

I've seen some cars that the shock had broken the mount, and continued right through the trunk floor.

The coil over manufacturers didn't engineer their product very well if they expected the stock shock mount was going to hold the weight of the car on an A body. I have mentioned this previously on another thread, only to have my warning ignored.

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Last edited by Sirrotica; 01-15-2022 at 01:00 PM.
  #22  
Old 01-15-2022, 01:45 PM
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Also, are the effective spring rates going to be wonky if there is a 2.5" difference between where the lower spring perch is adjusted to on each side of the car?

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  #23  
Old 01-15-2022, 01:58 PM
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I just lift the rear of the car by the axle and the shock mounting point is very solid. The crossmember has no cracks and the gap between the back of the mounting point to the trunk floor is the same as when I installed the coilovers. I much appreciate the help and concerns and previously read about the possible problems it could cause. I decided to go with the coilovers to see what difference it makes. Being that a OEM rear coil is only 130LBS/IN tension and this car is just a mildly driven cruising car I decided to give it a try. If it was a high HP drag car I would not have done it. That being said, I hope I never regret doing it

Could it be the rear sway bar, being it's mounted to the lower control arms be holding the driver side to a fixed position in relation to the pass side since it was tightened with the unbalanced height? Or the lower control arm bolts too tight and polygraphite bushings fighting movement?

  #24  
Old 01-15-2022, 02:04 PM
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The spring rates are given as linear and the car drives great. I love the ability to adjust the shock stiffness as well. There is a particularly bad dip on my way to work where the one tire scrapes that I use as my testing point to determine if I've conquered this issue....... NO success yet.
Quote:
Originally Posted by ZeGermanHam View Post
Also, are the effective spring rates going to be wonky if there is a 2.5" difference between where the lower spring perch is adjusted to on each side of the car?

  #25  
Old 01-15-2022, 02:21 PM
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It can only be one thing then, the spring is badly tempered, and won't hold it's rate. It happens infrequently that the heat treat isn't adequate, and a spring will sag as it shows in your pictures.

If you had a spring tester, and compressed each spring, it would likely show the one has way less rate than the other.

The manufacturer should have some warranty on them, so I'd contact them, showing them your pictures of left, and right sides comparatively. If you have one of the back of the car showing it listing to one side, that would also be helpful.

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  #26  
Old 01-15-2022, 04:00 PM
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Quote:
Originally Posted by madtexan View Post
The rear axle is centered on the frame. Checked it this morning and measured from the inside of frame to center of upper side diff cover bolt and they were within 1/8th inch.

Every time I try to solve one of the issues with it, It fights back and says "Leave Me ALONE!!!" I love it and hate it at the same time

I'm also trying to lift this same side of the car to match pass side by adjusting the new rear coilovers. QA1 with 150lb springs. I started with a 1 inch lower difference on driver side (side that scrapes) at fender lip so I have tried to set the coilovers to raise it to reduce scrape. I set it to match pass side and every time I come back after test drive it settles back down to nearly same position. The difference between the sides is around 2 1/2 inches when measuring the amount of thread showing on the coilovers. I only wanted a 1 inch lift but that much diff at coilover seems excessive. Almost like something is locking into place and once it goes past that point, that is where it stays. I'm so frustrated!!


p.s. Had to temporarily remove tailpipes and will adjust location due to installing coilovers.
Maybe double check the measurement by measuring from the outside of the frame to the axle flange/drum where your wheel mounts to just to make sure the axle is really centered.

I am not liking the angle of those coil overs. It also looks like the way they are adjusted, that they will bottom out or coil bind. I think you might be better off with stock type coils. Also, the way the car sits is also affected by the front springs, so you might want to check those out too.

  #27  
Old 01-15-2022, 07:11 PM
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I checked more axle to frame measurements and the axle is centered in frame but the body to frame is not. maybe grind away a little more of the inner fender lip. I'm afraid to mess with the body mounts to shift over because of the possibilities or other things getting messed up.

As far as the coil overs spring settings being so different, I decided I can swap them from side to side to see if one of the springs is weak. I have nothing better to do this weekend. Football will be watched later tonight.

While the coil overs are out of the car I can put a floor jack under the rear pumpkin and make sure both sides move up and down equally. Am I right to expect both sides should move evenly when lifted up under the center? wheels/tires are off car. Any other suggestions to check out at this time?

BTW, the coilovers never bottom out and the front sits perfectly level side to side. I have seen a bracket that mounts on the rear axle and the the inside of the lower arm mount that brings the coil more inward to reduce the strut angle though I think it is highly overpriced.


Last edited by madtexan; 01-15-2022 at 07:33 PM.
  #28  
Old 01-15-2022, 07:37 PM
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When I worked the line at PMD in those years the repairmen would quite often get a repair ticket with "shift body right" or "shift body left" , they would loosen the body mount bolts and simply pry the body over and retighten, job done. This problem was not unusual but not that frequent either but did happen. I guess what I am saying is the body being to one side or the other is a real possibility but when the car was completely stock no one knew. I don't remember the big Pontiacs having this problem, only the A cars.

  #29  
Old 01-15-2022, 10:06 PM
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Bob6258, were these cars completed or rolling down the assembly line?

  #30  
Old 01-17-2022, 10:16 AM
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Those cars were on the line after all the front end sheet metal was installed, I don't know exactly what they knew to cause the needed body shift but 2 repairmen in the pits could do it in about 60 seconds.

  #31  
Old 01-18-2022, 01:49 PM
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Mine was originally like this too. When you looked at the car from the back the rear tires were clearly like an inch or so off from side to side. I did a leaf spring swap with all new bushings etc. Straightened everything out. I dont know why, but it definitely worked.

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  #32  
Old 01-25-2022, 06:12 PM
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I measured all my rear control arms to see if they are off center and they are not. My rear diff/axle is centered in the frame. It's the body that is not mounted square on the frame. I ground away more of the inner fender lip but not enough. I'm swapping coilovers from side to side to see if one coilover spring is soft but it appears they are not. Maybe just go to 245 width tires and issue goes away. (Band-aid fix)


I decide to put a UMI Performance upper reinforcement brace behind the upper coilover mounting points. I also plan to install some lower reinforcement brackets they have that mount bottom of coilovers to inside of lower control arms. Makes the strut more vertical instead of the sharp angle. Unfortunately the lower brackets are on long 2-3 month backorder.

https://www.umiperformance.com/home/...r-bracket-kit/

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