Hey all, looking at the front leaf springs on my truck, my brother noticed that the shackles are in the front and the fixed mount is at the back of the spring. He knows more about suspensions than me, and suggested we reverse the mounts to put the shackles in back, similar to what Chevy switched to, in later years. The goal is a smoother ride, since the shackle will have a smoother path backwards when I hit a bump. I searched all over to see if this had been, but can't find any info. I'm just curious about the effort vs. benefit of this idea. Have any of you seen/done this?
I think the effort/benefit is way too far off. I don't know if Chevy changed the shackle location or not. And if they did, if it was to improve the ride. Lets say they did. But they still switched to independent after that. If softer ride is what you want, go independent. Otherwise leave it as is.
Push or pull on the spring? That question is like saying the rear springs should be flipped as well so the force pulls the vehicle forward rather than push it. Leave it.
So your brother is going to re-engineer something GM and other did for 50 years? Rears were made that way for a reason and so were the fronts. When designed it was not done because the bean counters said it was cheaper.
I know GM did switch it, his '73 has the fixed mount in front, and the shackle in back. Hit a bump, the force makes the shackle swing up and back, definitely more logical than my '58, with the shackles on front and angled down and forward. Hit a bump while moving forward with that setup, and it's a lot harder for the shackle to want to swing up versus bind into the frame. I know it'll be a better ride if I switch, I am just questioning whether the improvement will justify the work. Since so few have done it, I'm gonna just ***ume the improvement isn't that much.
While that may be a fairly common mod a**** the ******** off road 4x4 brigade I'd think it would be a waste of time and effort on a street driven rig that seldom saw anything rougher than a gravel driveway.
It was a common modification to jeep CJs in the '70s. They are less dodgy with the shackle in the rear. GM basically lost the leaf front suspension on anything but 4WD in about '60. On later model GMs one end of the spring was longer than the other, if I recall the long end went to the shackle. I am likely to get that wrong and have nothing to look at, but check your vehicle, if it has a long end than it is not as simple as it sounds to get it right.
Have you looked at how far the shackle moves, and in what direction, on a 50s chevy truck front suspension? The spring is rather flat, there is little motion of the shackle forward when you hit a bump, and no upward motion (the bushing solidly mounted in the frame bracket keeps it from moving up). There is always vertical load on the shackle, and it does increase momentarily when you hit a bump, but it will do so whether it's at the front or back of the spring. This is another one of those "don't fix it if it ain't broke" posts.
Thanks, guys, for the thoughtful input. My brother is indeed coming from the view of someone who knows tons about 4x4 and off-road suspension (and his truck is also 4wd, which is what I was looking at), so that is the perspective he has. As far as gravel driveways, we have a bit worse here in Reno, lol! Not sure where the heck our gas taxes go... Thanks again, all, for the food for thought
The Jalopy Journal
