frame help

[mrgoodwrench_420]

i am looking in to frames and want to know the what the pros and cons are of coil and leaf spring and what they are worth

[Longhorn Man]

Coils ride better
coils plant power better
coils are rated at the same GVW as leafs

[4tiresngas]

I agree. NASCAR runs trailing arms and coil springs...performance. Also, I think it is easier to adjust your ride height with coils springs to get the stance you want.

[roj2323]

[llegos]

if coils are so great and all, why arent they still used, and why were leaves available? Im not trying to be ignorant, im just uninformed

[Green Machine]

One claimed advantage of leafs is that they support each side of the frame in two places and distribute the load across those two points, where coil concentrates the load mostly right over the coil. When GM used helper springs on the coil models, notice that it helps support the back of the frame. Leafs may be better if you have a heavy trailer attached to the rear bumper, since you have a spring attached nearer the rear of the frame. Leafs are probably cheaper to produce, and since all the 4wd were leafs, I suspect as the percentage of 4wd grew vs the 2wd, that the coils went away. My 88 C1500 2wd has leafs and even given 20 years of possible leaf refinement, my 68 and my 70 both have coils and do in fact ride better.

[FormerMember]

Also, coils came back

Leaf suspension is cheaper to manufacture. The spring locates the axle as well as supports the vehicle weight. They also tend to be stonger for the reasons already stated. Two areas anchored to the frame.

Coils do not locate the axle, so more moving parts, bushings to wear out, bolts to break, etc.

[qksilver]

I have both styles. I prefer leafs for towing and carrying heavy loads. Even with sway bars front and back, the leaf spring rear doesn't sway and going around corners loaded doesn't feel as tippy.
The coils do ride better and with proper pinion angle will hook up better in high horsepower situations.
Steve

[RPOZ11]

Years ago out at Ascot Speedway, now demolished, this question was presented to the owner/head guy over at PRE; I forget his name: Gary Sigmund????
Anyways, he stated that under demand, the trailing arm suspension tended to load up the rear of the suspension causing improper transfer....at least this is the best of my recolection as best my memory serves me.
This was based upon knowledge and technology years ago; Unsure what the current understanding suggests....

Leafs seem more practical to me and I have never experienced a bad set-up while towing. My 69 Suburban would tend to allow trailer sway at certain speeds. That truck was a trailing arm-coil spring set-up....
Just my thoughts....

[djracer]

my 01 sub 4x4 has coil rear!

[Robert1970C20rstbukt]

The downside to coils is they are weaker than leafs. There was a 2000lb Lincoln engine driven welder in the back of my truck when I got it and it was sagging big time. If it would've had the optional leaf overloads it might have supported it better.

[Longhorn Man]

However, when they were new and not x00,000 miles old, they were both rated for the same load.
A few years ago I had towed a SMALL u-haul trailer that was only semi loaded with my old SWB GMC.... coils in the back. Anything over 55 and the rear was swaying all over the place. I came on here and asked about it since all I had towed with was leafs previously. I had been told at the time that my swaying rear was probably due to worn out parts...and since it was in fact a 500,000 mile old POS...and most every piece of rubber underneath was junk anyways, I considered it as a probable reason.
If this is fact or not... I have NFC since I have never towed with a good coil rear.
i DO know Huck overloaded his old 1/2 ton all the time towing, and I am thinking he had coils.

[chevymad]

The spring spacing is wider apart on leaf's too. This gives an advantage to sway. If you've ever made a trailer out of a coil sprung truck.. you know the thing is really really bouncy compared to a leaf unit as well.