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Discussion Starter · #1 ·
Is there an upper and lower end to a front coil on a 67 Bel air? I have a new set of Moog 6304's, and one end is tangential and one end is a hair less tangential, but not square cut either. Definitely different, but not by much. The wire is cut the same, but the coil is bent ever so slightly toward the next coil. Which end goes up? Thanks everybody.
 

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Coils that are not evenly spaced when free standing are a sign of a proportional spring rate instead of a constant rate spring. It is soft when empty but gets progressively stiffer as you load the vehicle.

As to which way is up I have no idea. I will wager if your existing stock spring has a tangential end on it now, then your new spring goes in the same way as you took out the original (tangential springs generally fit over a sheet metal cup or are clamped in place).

If your stock spring doesn't have a tangential end then they sold you the wrong springs for your car.

Big Dave
 

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Discussion Starter · #4 ·
More info

Further research shows: the one end is essentially square cut. It will stand on its own, though it leans a bit. It sits very nicely in the control arm groove while on the bench. Something else I've noticed, it will not allow for proper installation in its current configuration. With the bottom seated in the control arm, the top is no where near the inspection hole. I think I will cut about 2/3 to 3/4 off the top coil so it will align with the hole and seat properly in the arm. These are Moog 6304, original ride height, stock replacement springs for 1967 Bel air, 2dr, 396, no a/c. Of course they list many other applications as well. Guess one size does'nt fit all. Incidentally, the Moog application guide shows tangential on both ends.
 

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You should never cut anything but a full coil at a time.

The spring has to be physically identical in terms of whether the ends are pig tail, square end, or tangential to use Moog's description: though I call the pig tail a tangential, and the what Moog calls a Tangential I call a square cut; so I can see where the confusion is entering the conversation.

http://www.moogproblemsolver.com/moog/wp-content/uploads/2012/08/MOOG_Coil_Springs_Spec.pdf

Big Dave
 

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Discussion Starter · #6 ·
Interesting. Moog and Eaton apprear to have different views on what is tangential and square cut. No worries though. The end I plan to cut is the only end you can cut. And remember, I'm only cutting it so it will seat properly top and bottom. It's that or toss these and buy some new ones.

From Eaton's site:
Cutting Coil Springs

When it’s ok, and what NOT to do.


Every now and then the question comes up and customers want to know, “Can we cut coil springs to lower a vehicle?”
Our answer is, “The design of the end of the spring determines if it can be safely cut. If it has the right end, it is OK to cut it.”
Coil springs have 3 basic type of ends -
  • Tangential- where the end of the coil continues to twist off into space. A spring with a tangential end would fall over if you tried to stand it on its end.
  • Square – the last coil bends back down to touch the coil below it. This style end allows the spring to stand up when placed on this end
  • Pigtail – the last coil of the spring is the square type but has a much smaller diameter than the coils in the body of the spring.


The type of ends a coil spring has is determined by how the springs are mounted in the suspension. A coil spring can have 2 of the same ends or it can have 2 different ends.
The only Coil Spring Ends that can be safely cut are Tangential Ends.
Because Square ends and Pigtail ends are designed to make full contact with their mounting points, they would have to be re-shaped after they were cut. But in order to re-shape them the steel would have to be heated and heat is a spring’s worst enemy.
So, Coil springs with Square or Pigtail ends can not be safely cut.

A safe place to start is by measuring how much you want to lower the vehicle. Then cut 1/2 that measurement off the length of the springs and reinstall them. Then take her for a drive, and drive it like you stole it to get the springs well worked and seated properly.

Now check your ride height. If she’s still too high, repeat step 1 until you get the look you want.
Remember, you can always take more off, but you can never make them longer.
 
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