The perfect spring?

kmas0n

I have no idea what I'm talking about
Supporting Member
Ride of the Month Winner
Joined
Apr 6, 2019
Messages
1,381
Location
Sedona, Arizona
I've been searching for rear springs for a while. My jeep is very light, without armor, No spare, no rear seat, soft top, minimalist bumpers, etc.

I need a spring with:
a stack height of less than 4.5" (full bump)
a ride height of 11.5-12"
an extended length of at least 16"

The savvy 4" springs may fit the bill, but I cannot get an accurate stack height, and I would be guessing about ride height. I needed something that was too long, that I can cut to size...

And I found it. In my garage. for free*

The front springs for a 2018+ JLUR
Free length of 18"
Stack height of 4"
As it sits in the JL, ride height is 10"

The same spring on the rear of my TJ... 12..75". If I had heavy bumpers, hardtop, spare tire etc, I imagine it would be pretty near 12" or the height of aftermarket 4" lift springs.


IMG_20201125_111020.jpg



The coils are 0.5 thick... 8 wraps mean that the stack height is 4". I have room for 4.5" so that's a go.

IMG_20201125_111143.jpg


And the free length is 18", considerably more than the 16" I need. This isn't a bad thing. That means at full droop the springs are still pushing down on the axle like a coil-over.

IMG_20201125_112240.jpg


So these springs are a bit too long for my applications, but fortunately, one end of this spring is tangential... That means you can cut it. Coil springs come in several shapes— tangential, square, and pigtail. They can be identified by appearance; in tangential-style springs the last coil just ends, with no shape formed. It is not good practice to cut off a pigtail or square.

PXL_20201126_143651851.jpg


I cut the springs so the free length is now 17", and ride height is now 12" dead on.

A tangential spring end should have some sort of bushing or spacer to ride in, and the factory one fits the bill. I did have to fabricate a 3.5" post for the spacer to sit around, but I'm not sure it's required. It's just proper

PXL_20201126_155516464.jpg


And the finished project. Exactly 12" of spring height (or 4" of lift). short stack height, extremely long free length springs... all for free*

PXL_20201126_155638217.jpg


*The concept of JLUR springs being free, reminds me of the belief that electric cars have zero emissions. These free springs only cost me $60k! That electricity does not cost zero-emissions capture. It's likely however that you can pick up a set of factory JLU/R springs and isolators for nearly free from craigslist or scavenging dealerships.
 
Aren't "Savvy 4" springs" just Currie 4" springs? Or does Savvy make their own springs now?

Very cool though that you managed to make those JLUR springs work for you. Like you said...only cost you 60k :LOL:
 
Aren't "Savvy 4" springs" just Currie 4" springs? Or does Savvy make their own springs now?

Very cool though that you managed to make those JLUR springs work for you. Like you said...only cost you 60k :LOL:
Savvy...
Currie...

I know better, but I've never been able to separate them in my mind.
 
Most 2.5"-4" springs are 5.5" stack height.
Stock springs are 3.5". currie is basically 5.5"

Running a 4.5" stack height requires a 1" bumpstop extension. A bolt on track bar relocation bracket requires 2" bumpstop extension without a body lift.

The rear fenderwell upper lip has to be cut and folded flat to operate a 35" tire on a 1" rear bumpstop.

Ome 2-2.5" kits send out a 3/4" rear bumpstop extension, yet the stack height is 5.5". The brackets hit the body before the 13.5/22.5" shock hits the bottom.
 
It looks like the top of that tape measure needs to come down 3/4" and the left side of the spring isn't fully loaded. I don't have a way to compress a spring but measuring 8 coils at 1/2" each seemed pretty accurate. but either way, way to shit on my happy day. Oh well. I guess the search continues.