Springs moved under the frame

[jeeping1974]

I have been looking at pictures over the Dodge section for about a week now and I have only seen two full size Dodge pickups where people moved the rear leaf springs from side of the frame (post mount) to under the frame.

I know that the frame would/should be boxed in but moving the springs under the frame would be a relatively cheap way to lift the back end and gain quiet a bit of flex.

Is there a reason(s) why more people have not done this? Too much sway if the vehicle is still driven on the road?

[ffdustyw]

Moving the leafs under the frame works fine. Most people get enough lift and flex out of flipping the shackle. Plus it takes less work.

[jeeping1974]

Originally Posted by ffdustyw

Moving the leafs under the frame works fine. Most people get enough lift and flex out of flipping the shackle. Plus it takes less work.

Less work always sounds good.

I'm starting to plan a build on a mid 80s 1/2 ton (reg cab/short bed) and was thinking about how I could get the most flex without linking it. I've got a set of 63" Chevy springs that I would install in the rear, hence the question about moving the springs under the frame. I've already have hangers and shackles so it wouldn't cost me anything extra to move them.

Just didn't know if there was any downside to it.

[swirvin21]

slightly less stability since the mounts are further inboard, less protection ( need to add front hangar ramps)

[ffdustyw]

If I was to do it I would french the leaf into the frame at the front hangar. There would be more of a stability issue as far as body roll in the rear. For a low speed crawler I think you would be fine. If you plan on carrying alot of weight up high in the bed then it might not be a great idea.

[jeeping1974]

Why french the leaf into the frame? Allow obstacles to slide under the leafs instead of smashing the hangers on them?

Only thing that would be mounted in the bed would be a spare, tool box and fuel cell so I wouldn't have to worry about being too top heavy.

[evilram]

Originally Posted by jeeping1974

Why french the leaf into the frame? Allow obstacles to slide under the leafs instead of smashing the hangers on them?

Only thing that would be mounted in the bed would be a spare, tool box and fuel cell so I wouldn't have to worry about being too top heavy.

That may seem like a small amount of weight until you factor in a few things:

Call the fuel cell 20 gallons,
that is roughly 125lbs (counting cell),
spare tire & wheel: 150 lbs
tool box: 75???
Random metal & all: 25 lbs??

375 lbs is alot of weight, and putting the springs roughly 40" apart is going to make the ol' girl a bit tipsy...

And yes, if you're going to do it, french in the hangers. Not only will you have less work in creating a nice hanger, and you'll be able to lower the mount. But, keep in mind you will need to be quite knowledgable about the "swing" of the shackle. You don't want the shackle to hit the frame under the flex of the springs.

[dakota44040]

We have done this on a couple of rigs, a little too tippy on side hills for my taste. The frame cracked right above the front spring mount on both rigs, so boxing the frame is a must.

[swirvin21]

X2

If you think about the placement of the OE front hangar, you'll notice it spreads the vertical load partially into a twist on the frame. The OE frame is designed to flex at the cab/bed, so placing the hangar under the rail will actually put more vertical stress on the frame. I don't honestly see a big benefit to moving them inboard. You can weld new hangars in the stock locations further down on the frame for cheap lift. Do you have 3" 2500/3500 leafs or 2.5" 1500 leafs?

[jeeping1974]

Thanks for all the insight and info on this guys. It looks like I will probably just keep the springs on the outside of the frame and make up some of my own and flip the shackle.

Originally Posted by swirvin21

Do you have 3" 2500/3500 leafs or 2.5" 1500 leafs?

63" chevy springs.