Front Coil Springs

[mark69sportsroof 31]

Hi Everyone,

 

I am finishing the restoration on my 69 Sporstroof.  I changed out the 351W for a FE 390.  I have stock suspension and steering with KYB shocks.  I have the 428 springs.  All new parts across the board.  I did the 1" Shelby drop.  I noticed that when the car is on the ground both springs are bowed in the middle.  Any suggestions on the cause and the fix.

 

Thanks  Mark

[Opentracker 4]

Is the bow inward or outward?

[mark69sportsroof 31]

I will check in the morning.  The car in at a local automotive shop.  Thanks

[mark69sportsroof 31]

With the tires on the ground, the front coil springs  bow out toward the tires.  The shocks are right against the other side of the coil springs.  Everything is stock except for the 1" Shelby drop.

 

Thanks  

[1969_Mach1 333]

I don't know if it makes a difference, but are the lower spring perches installed correctly?  The 1" Shelby drop wouldn't effect it.

[mark69sportsroof 31]

I believe the spring perches are installed correctly.  I didn't do that part of it.  How would I tell if they are?

 

Thanks Mark

[det0326 179]

I believe the spring perches are installed correctly.  I didn't do that part of it.  How would I tell if they are?

 

Thanks Mark

The stock perches has a radius cut on one side to clear the hump on top of the UCA where the ball joint mounts. The other way to tell is the tang or stop on the perch that the end of the last coil goes against should be toward engine bay. I just ran into this myself as to which way they are installed a few weeks back.

 

Dave

[Rsanter 152]

The only time I have seen the condition you describe is when someone had heated the springs with a torch to lower a car.

They do,it,to allow the springs to sag a bit. The problem is that they remove the temper from the springs and they will continue to sag until they get to where you describe.

 

Bob

[mark69sportsroof 31]

I did have the springs powder coated. I know he bakes it for 45 mins or so at 400 degrees.  Could this be the problem?

[1969_Mach1 333]

Do you know for certain the lower perches are installed correctly?  I still wonder about that.  Those temps to cure the powder coating are less than half of the annealing temps.  My front springs were powder coated from the manufacturer without any issues.  I wouldn't think so, but I guess it is possible if those springs were cold rolled that 400 deg for 45 minutes could have relieved some residual stresses from forming, now causing them to bow.  I would still double check that they are installed correctly.  Were they straight before they were installed?

[timsmustang 12]

The spring perch is most likely installed 180 out.  The tang should be towards the engine compartment as mentioned above...otherwise the springs will not sit correctly.

[1969_Mach1 333]

I hope they double check the spring perches before condemning the springs.

[mark69sportsroof 31]

I took the tire and shock off today.  Here are some pics of the springs and perch.

[1969_Mach1 333]

Now that I see it, it almost looks like the top of the spring is not seated correctly.  Is the motor in car?  If so, does it sit at the correct ride height when on the ground?

[det0326 179]

It seems the last coil at the perch is clocked a little past the stop and the stop looks bent down. May just be my eyes, hard to tell from the pic's.

[mark69sportsroof 31]

The motor is installed.  Best I can tell the perch and the stop are correct.  How do I tell if the top of the spring is positioned correctly?  It looked a little off centered. It's hard to get pics because of the flash.  The ride height is OK.  I thought it was about 1" to tall with the Shelby drop.  I will get pics of the spring top and download tomorrow.  Thanks for all the good info.

 

Mark

[1969_Mach1 333]

It seems the last coil at the perch is clocked a little past the stop and the stop looks bent down. May just be my eyes, hard to tell from the pic's.

After a second look, I also don't see the stop that should be against the end of the coil.  Cannot tell what happened to it from the picture.  Also, the upper still looks like its not seated or something.

[MikeStang 247]

Perches are installed correctly and spring is in right on the bottom, just check to be sure they are seated on the top good, and that's about it.

They may look a little bowed until you get the weight on the springs and compress everything.

Also I have noticed that sometimes for whatever reason if you install the spring into the perch and rock it back to try to install it in the top it will actually lock the perch back into an odd position but it doesn't appear that yours is too far back and it all looks right.

[Opentracker 4]

It looks like the perch is pointed at the shock tower cover, not the center of the upper spring seat ( hole the shock goes through). To bow a spring, the top or the bottom has to be at an odd angle. With the car sitting like it is in the bottom photo, try and rotate the perch to see if you can get the bow out of the spring. 

[mark69sportsroof 31]

Thanks everyone.  I noticed today the top part of the spring is off center about 3/8".  It is closer to the tire side then the engine compartment.   I will try and move it to the center of the top of the shock tower opening tomorrow. 

 

Mark

[mark69sportsroof 31]

I tighten down the coil springs and tapped the top of the spring about 1/2" and it aligned the springs.  Thanks to all for the input.

 

Mark 

[1969_Mach1 333]

That's good news!  It was hard to be certain from the pictures, but the top of the springs didn't look quite right.