jc30f in a 2.3 regular cab?

steevn · Feb 22, 2013

Hi
My truck is all stock, the front is sagging and it rides like a shopping cart. So I've been considering throwing in skyjacker jc30f springs. Would this yeild too much lift for my stock drop brackets and radius arms? What about rancho rs6423? I read these sack out over time, would they be better.

jeep cherokee xj coil swap

4x4junkie · Feb 22, 2013

Jeep coils are not going to do a whole lot for a stock suspension, there's just not enough travel available (you'll be bottoming & topping out a lot).

Unless you're planning to lift it, I would suggest stock replacement coils designed for your 2.3L truck, and maybe look into better shocks for it (more often than not, ride quality concerns can be addressed with better shocks such as Bilstein).

steevn · Feb 22, 2013

Ok thanks. I'll try some better shocks.

steevn · Mar 13, 2013

Well I took the shocks and swaybar off and test drove it...no diffrence. Then I measured my camber at ride height and found that it was just slightly positive, meaning my springs are not sagging, so I then checked the beam pivot bushings, they were fine. This badboy just rides front low, and the stock coils are really stiff.

Here's what I found out about the stock coils on a 2.3 reg cab 4x4:
free length 13 5/8"
compressed spring length 10 1/4" (on wheels, level surface)
.617 wire, 4.25 coil diameter, 7 active coils = 379.26ppi (from the spring rate calculator)

So from free to compressed is a diffrence of 3 3/8"

3 3/8" x 379.26ppi would be pretty close to 1280 pounds of force compressing the spring.

1280/1.5 for the ttb gives about 853 pounds on the front left tire (I only measured left side).

I'm actually getting a ttb ratio of about 1.4 for the driver side beam and 1.55 for the passenger side. Does that sound right?

If I leave this thing stock I'm probably not gonna have any teeth left, so I ordered a set of jc30f on amazon for $170 + free shipping. I think maybe these will give about 3" lift.

4x4junkie · Mar 13, 2013

steevn said:
I'm actually getting a ttb ratio of about 1.4 for the driver side beam and 1.55 for the passenger side. Does that sound right?

No, it's the same ratio for both sides if you have stock radius arms.
Putting extended radius arms on causes a very slight deviation to a higher ratio (the P-side also a hair more than the D-side), but it's not enough to be significant.
http://img.photobucket.com/albums/v173/sfr4x4/ttbsymetry.jpg

Having took your shocks off and no difference at all tells me those shocks were toast (makes sense why it's riding like a shopping cart lol).

steevn · Mar 14, 2013

Wow! I didn't even think about the other pivot point, the hinge line is from the radius arm pivot to the beam pivot. So does the 1.5 come from dividing blue line distance into green line distance?

4x4junkie · Mar 14, 2013

Yes, the difference in distance shown by the blue & green lines is what creates the leverage ratio.

steevn · Mar 18, 2013

Well the jc30f's came in the mail so I measued them:
free length 19 1/2"
wire diameter:.597" coil diameter:4.625" active coils:7.5 = 240.748ppi
Based on my vehicle weight these springs should compress 5.32" mounted in the beam with weight on the wheels.
19.5" free length - 5.32" of compression =14.18" compressed length.
Thats 3.93 inches longer than my stock compressed length, with the jeep isolator and the pipe hardware (as seen the the jeep coils article) thats probably a little over 4" lift.

Heres some pics of jc30f next to stock spring, and I fit it in the truck just to see. With the jack directly under the spring it compressed 3.5 inches to just lift the frame off the jackstand, that would be 842lbs, which is pretty close to the 853lbs calculated from the stock springs.

bobbywalter · Mar 18, 2013

you may have to custom seat angle to keep the coil bow under control.

and some bags to tune

4x4junkie · Mar 18, 2013

Well, I did say earlier Jeep coils probably wouldn't be best thing to put on a stock suspension...

I guess if worse gets to worse, find your self a 3-4" lift, then they'll fit great, and you'd actually have some room for flex without the bumpstop being so close right above the axle.

FWIW, those coils are 1.5" longer than the 3" Rancho XJs I had before, and 2.5" shorter than the JC60Fs I have now. Could it be possible you were sent JC45Fs by mistake?

steevn · Mar 18, 2013

It said "jc30fs" right on the spring, I don't know what the "s" is for, they did seem a bit long. I'm not just gonna stick em in there and hope for the best, haha. Right now I'm thinking about extending the stock brackets about 2" and pushing out the bottom joints for about 2 more. Then just cutting and welding some tube into the radius arms and welding the radius arm pivot points into the tranny crossmember. That one beam pivot is cast though. Can that be welded? I don't recall ever welding anything thats cast. Or yeah just get a 4" lift without springs and call it a day, way less work but more money. Gotta think about this.....

steevn · Mar 18, 2013

bobbywalter said:
you may have to custom seat angle to keep the coil bow under control.

and some bags to tune

Yeah I tried to put it in with the radius arm connected and it bowed right out of the bucket, I chained it before trying though.

4x4junkie · Mar 18, 2013

I think the "s" means 'single' (at least i recall they had something like that in their catalog for rear leaf springs which they sold either in pairs or singly).
It doesn't seem like someone would buy a single spring very often unless maybe you damaged one that was near-new somehow though :dunno:

As for the bracket, I wouldn't suggest welding on it. Look for a set of lift brackets instead.

bobbywalter · Mar 18, 2013

single rate

steevn · Mar 5, 2014

Well I've been doin alot of work on my truck but finally got back to this. So heres the stuff that I got

jc30f in a 2.3 regular cab?

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