Im going to cut the factory rear coil springs on my 63 chevy impala, any advice from those who have done it before? I don't know how much I want to cut off but figure I'll cut a little at a time and re-install till I'm happy with the rear stance.
Try a half coil at a time. I did a full coil the first time I cut my springs, and it dropped me too low.
Some GM cars have coil springs that cannot be cut because of the way the coils are wound. You may need to invest in "lowering springs" to do the job right. Jamco is one source, but I'm sure there are others. Just tell 'em how much drop you want and they'll make you the right springs.
barrel wound springs, those that decrease in diameter at top and bottom: if you cut, there's no place to seat the spring anymore otherwise on a straight wound spring, where the diameter is the same: cut away. start with 1/2 coil at a time. an abrasive wheel makes short work of it. keep in mind, the shorter the spring the stiffer the spring rate becomes. as a generic example: take a 250lb/in coil with 8 winds... cut one off and it may now be a 280lb/in coil. gets stiffer as it gets shorter.
DON'T do one side til you're happy and then start doing the other side. BOTH sides will then be way too low. BTW-you didn't say how much you want to lwr it
If it's a 64-72 GM intermediate (Chevelle/Skylark/Lemans/Cutl***) there's actually an impression in the frame that will contain the upper part of the coil after the pigtail is cut off. I do it all the time. I also run a section of heater hose on the upper 1st coil after cutting for squeak control
I'm going to get under there later to make sure I have the type that are able to be cut. Also I'm getting 1 1/2" lowering coils for the front so I want the tail end to sit just a little bit higher. I might be better off waiting till I get those and installed before cutting the rears.
mine weren't progressive, but I went the opposite route, and put Cargo control springs on my El Camino to raise the rear. Honestly though, buy the new springs. They can be had for less than $100 and the ride quality is much better than a worn out 50 year old spring. beware though, just a stock spring will raise the rear, so plan your drop accordingly. Mine went up 2 inches.
On another thread someone once advised submersing them under water while cutting to keep from over tempering them.
I'd imagine that would give you a nasty shock from the cutoff tool. In all seriousness, I have done a few hundred, over 30+ years. Used to use a torch to cut, not I just use a cutoff disc on a 4-1/2" grinder. Don't over-think it.
At most with a cut off wheel cutting the spring you "might: change the structure of the metal for maybe a quarter or half inch at the max. As Gimpyshotrods said above don't over think it. Another option may be sorting through a spring catalog and finding a pair of springs with a similar rating and diameter that are a bit shorter. Myself, I'd cut both old coils a half turn at a time and by trial and error get it were I wanted it to be and done. If you want new ones later Amazon has a good price on a pair. They also show all of the specs on them which is nice to have in the car file. http://www.amazon.com/Moog-6033-Constant-Rate-Spring/dp/B000COMSIQ
Go to moogs web site and look around they have a whole chart of all of their springs with all the ratings and lengths there. -Pat
Ok guys I decided to do it right and order some already made for lowering. I bought some american made 2" lowering rear springs. I rebuilt my rear suspension years back so I know replacing them isn't all that difficult but what I am wondering is do I need to get different shocks? I know the ones in there now are old air shocks and still seem to be holding up well.
i think you did the right thing by buying new lowered springs if you need new shocks you might want to stay with air shocks that way if you need a little height you can raise it up. i have air shocks on my 51 merc and i have a very small coleman air compressor 12 volt if i need to raise the rear a bit i just add a little air. works out great.
Cutting coils with a cut-off wheel or even using a torch is OK. The free end does not need the heat treatment anyway. Cut-off wheel will not heat up the metal enough for any problems. Cutting coils is old as coil springs. Do it right and no problems. Heating the middle of the coils springs to lower it is what is bad. That destroys the heat treatment of the spring, and makes it distorted. Even heating two areas on opposite sides of the coil to try and balance it out still makes the spring useless for long term.
Coil spring clamps though not always ideal is an option to consider. They can always be unbolted with no harm done.
Me and a friend cut 2 coils out of mine. (they were still in the car so may have been a little more) It dropped the hell out of it and still rode like a dream. The cross member would hit the reflectors in the center of the road. I wouldn't suggest going that low now but I thought it looked good at the time. That was in 93 or 94.
Still wondering, do I need to get different rear shocks since I'm changing the springs to 2" lowering ones? If so how do you know which are needed?
I would just heat the lower coils, done over a 100 in the last 30 yrs. You need to know exactly what your doing. But you dont have to remove the springs, takes 15 to 20 minutes total. Drive the car in, 20 minutes later, drive it out. Find an old hot rodder that knows what they are doing and it doesnt change the ride just the height, it is a true art form and probably the oldest way off lowering coiled spring autos.
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