Thread: Rear susp questions

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well if it just takes a long spring, the ones your going to get from your buddy will probably be too short!!!!!!!!!!!he will have already used the long ones---------


I probably have 30 springs around here from the mid/late seventys-----------seems that the ratings were wrong on most all of them-at that time more and more people were getting into coil over stuff and there production of springs rate, length, diameters were not very good

You just like being a dick or what? When it goes on the road, It'll have the right springs. If I have to buy them new, no problem. I can still use a set of my buddies to fab with. You should go over on yellow bullet, they'd love you over there.

For what it's worth, when you get to the point of selecting the springs for the final assembly, my years of circle burning have found that AFCO has the best selection of height and weight on springs, and their ratings always seemed to be the most accurate!!!

No, I'm not trying to be a dick-------you came asking for advice and then when I have posted some comments about what you asked for, you get offended?????????But if you have a logical reason to use the longest spring you can get before you even start something, I'd like to know what it is---maybe I been doing things wrong---especially trying to drag race occasionally since the late 50s----------


And if think that both me and the yellow bullet guys are--------------maybe its really you----------


If you continue to want any advice I would be glad to help you but PM me because I'll probably put this thread on an ignore setting------

VHT, I believe that you're on the right track. I was just talking about spring selection with Mike, 34_40, and he went through much the same thing before he talked to the guys at AFCO. Like Dave says, they seem to have more selection and more knowledge about coil spring application. Everyone talks about "spring rate" as if that's the only variable, but there is also a "load rate", or design load for every spring, and the load vs deflection plot for a coil spring is not a straight line, linear relationship over the whole range that the spring works through. As the load increases the deflection rate changes, too, yielding a load/deflection curve. Spring rate is the weight it takes to deflect the spring one inch, while load rate is the amount of deflection or spring height that you get with a given design load. You can take a very heavy spring that supports the car at your desired ride height, but rides like a lumber wagon; or a longer, softer spring that also supports the car at your desired ride height, but deflects more with load giving you a more comfortable ride. It's not just spring rate, and AFCO can help you get there when it's time for the final springs, IMO.

Keep plugging, you're gonna get there.

VHT, I think the rubber bushing would work better for you over the heim. The truck arm is designed to flex , where the rectangular tubing will not. The rubber would help here and allow some give when driving on rough roads. We used to narrow the truck arms to create more flex than stock arms. I will try to find the Moog dimension pages for their bushings. You can machine your own sleeves to weld into the rect tubing. Keep us posted on this.

On the four links, Jeeps use a stamped steel inverted "U" with small flanges on their upper and lower control arms, capturing rubber bushings at each end. In stock form they last for years, or many miles; but in more extreme off-road service they exhibit a lot of twist at full deflection of the suspension (one wheel high, the opposing wheel low) and lifted. I replaced mine with JKS upper & lower control arms, made of DOM with rubber bushings at the end, but also with long threaded coupling of the two ends for adjustment - http://jksmfg.com/images/T62507134.jpg Note that there are no jam nuts on these, which lets the control arm rotate freely on the threads in addition to the rubber bushings. They provide the best of both worlds, IMO, and I don't see any reason that you couldn't use a similar design in your four link if you have concerns with flex.

I know a few guys with C10's that have DOM trailing arms with poly bushings and they work fine. These are on trucks that are occasionally road coursed and driven daily with over 450hp. I never heard the stock trailing arms are made from a spring type steel either. They surely could be. They sure aren't really solid so I bet that's where the flex comes from. Riveted in like 4 spots a long the length of them, most are rusted in half up here. There are companies that build replacement trailing arms for the C10s as well and they are not a flexible type design. More rigid construction. My buddy has a 72 Suburban with a 936hp Duramax in it with aftermarket trailing arms and that thing flat gets it. He has taken it on Power Tour the last 3 years and this year he was kicked off a race track. It runs mid 11's and that thing leaves pretty dang hard. I was really surprised he still had that style of suspension in it.

Thanks for the replies, I fooled with Afco when I raced, they are good with great customer service. When I said I would throw a long set in it, I meant I would stick something in it to move it around. I will have to have it done before I can figure out the right spring. I just don't want that bouncing feeling like I seen in some, nor do I want to push on the back and it hits the ground. A lot of people cure that with air bags in the springs, I'd rather have the right spring. I usually set stuff up with a solid dummie shock that I fab up at the ride height I want. 67 to 72 chev truck forums gave me a link where a guy made his own out ot 2x3, they looked real nice and I guess worked good. The only thing I didn't like is he didn't weld a piece of tubing in where the U bolts go down though. I was thinking 2x2, 1/8 in wall box would be a plenty with rubber bushings. May be wrong. Ruff Stuff have and can make up tubing with poly bushings and a steel insert. they have a lot of stuff us hotrodders can use. Real good prices on most stuff. Thanks again for the help.

Late 40's early 50"s Olds used the so called truck arm suspensions first, , after over torquing the bolts to compress the rubber biscuits , the olds was known for hooking up, but the shorter arms lifted the rear of the body.

I finally got started on my chassis. Had to take a break from body work. Got my front susp almost done and getting ready to start on the rear. My Dodge has a 115 WB. I would think a 5 ft arm would long enough on the 2 bar set up. Need opinions please. If I had the extra cash I would go with Checkered Racing's 4 bar set up with coil overs, but I keep thinking about this trk susp, and I'd kinda like to see how it works. The only real problem I see is exh. That may be a challenge.