Rear Spring Lift

[WoodenBirdOfPrey]

I'm having a hard time understanding how a 1inch spacer converts to a 2.5-3inch lift...

In the front that 1 inch spacer translates to 2-3" of lift due to leverage.  The pivot point of the control arm is at the frame, and the spring sits on the control arm at between 1/3 and 1/2 of the length of the control arm.  Therefore that 1 inch change is going to cause a bigger change at the end of the lever (the control arm).

With the extended shackles in the rear, the exact opposite effect is the case.  Because the wheels/axles are in the middle of the spring and the length is being added at the end on the shackle, it takes roughly 2 extra inches on the shackle to get an inch of lift in the rear.

[carnuck]

Poppycock! You do the rear before the front unless the rears are custom springs.

Please explain why.

That's supposed to read CAN do the back before the front (just like I did my Spirit)

[A-A EAGLE]

Also in the Eaglepedia I saw something about anything over a 2inch lift can get rid of some spacing needed for the suspension to travel.



Did using this 1inch spacer give you this problem?

With the 1inch ring it is not necessary to change anything, just put them on. When you want more lift you have to you adjust a lot.

Anjo
Holland

[NYEagle]

Poppycock! You do the rear before the front unless the rears are custom springs.

It was explained to me that the coils are put in first because they can then either add or remove leaves in the back to level off the car. Can't do that with coils (safely). Makes sense to me.

[Yes, there are those "donut" spacers and also those really unsafe things that you jam in between the coils to get more lift. But I'm not installing safety hazards on my Eagle.]


~ Joe in NY

[eaglefreek]

I'm having a hard time understanding how a 1inch spacer converts to a 2.5-3inch lift...

It's called geometry. Not sure, but I believe it's called coil spring ratio. 1:1 would mean 1" of coil  height difference would be 1" of ride height. I read somewhere that the AMC springs we use are 1:2.30. Meaning, for every 1" of coil height it changes ride height 2.3".  In my experience the number has been pretty close.

[Prafeston]

Guess I've just never really looked at it real close down there...your first thought is that if you raised the coil an inch you'd get an inch of lift, but apparently there is more to it down there!

[Mavericke]

I didn't go over the whole post but for those interested in a cheap, sturdy and super easy lift for the rear end... I installed leaf springs from a 93 Dodge 1/2 ton pickup. Everything lines up PERFECTLY and you have to only drill two holes. One on each side and they fit like a glove.

The springs I installed were wore out for the truck... it was meant to be temporary but since they have a few extra leafs in them and they're made for trucks - they really did some work on my lighter weight Eagle.  The leaf springs alone give you about 2 inches.

I also used the shackles that can be found on eBay pretty cheaply and got about 4" total with the new leafs and the shackles. I got about 3" in the front with new espo springs and coil spacers. The entire job took about a half a day and that included basically swapping the entire rear end on the wagon.

It also got new shocks so it basically had a totally replaced/upgraded suspension all the way around and with those truck springs in the back - I doubt they will ever need to be replaced. Again, I got about 4" in the back and 3" in the front after the new Espo springs settled. This was the cheapest lift I could manage at the time without doing a full axle swap.

Anyway, just something to add to the idea pool here.

[carnuck]

On my Spirit I used the Eagle spring pack with the SX4 main leaf



It takes 50 bags of cement to make it sit level!

[carnuck]

Guess I've just never really looked at it real close down there...your first thought is that if you raised the coil an inch you'd get an inch of lift, but apparently there is more to it down there!

You also have the thickness and tension of the spring coils to deal with.

[siguy8]

I did this once before with the Add-A-Leaf, but now I've got a different SX/4 and new problems. My driver side leaf just broke yesterday. It drove fine today, but now that I figured out what the new noise was, I'm a little worried. Probably taking the wife's car tomorrow...

I've wanted to put a lift on the SX/4, so I think this just speeds up my timeline. I want about 2-3 inches above stock. Are ESPO springs my best bet (both Leaves and Coils)? Apparently Cherokee springs don't work on an SX/4... Or is there something else I can put on. I don't want to do much/any welding/fab since I don't have any sweet tools like that.

That much lift and I know I'll need shocks. I'll put wedges in to align the driveshaft, and I plan to replace bushings too. What else will 2-3 inches of lift require me to change? Someone mentioned brake lines...

I've got an '82 SX/4 with the 5 Speed Manual and 2.5L (no A/C)...

[siguy8]

Parts are on their way. I think I got the recommended combo with a mix of ESPO/suspensionking/Quadratec...

2" all around is only 10 days away! If everything goes well...

[Kippnidaho]

I was thinking of putting the add a leaf type of system on the 83 sx/4, which one should I order, ie: yj or grand cherokee. Any thoughts or guidance.
Thanks
 

[carnuck]

Grand Cherokee is coil spring front and back, soo......

[Kippnidaho]

So is it the Cherokee and the YJ then. Regerdless I am just trying to determine what add a leaf system to buy to match up to the SX/4. Thanks fer the help

[captspillane]

I add Cherokee XJ leafs. I use the top leaf from the sx4 and everything except the XJ top leaf. It supports the notorious weak spot in the SX4 and Kammback leafs much better than factory. XJ and CJ (probably YJ too) have the same width and similar length.