Leaf spring question.

[bdunnam]

Ok, so here recently I did a spring swap on an 80's chevy pickup, and I noticed the front springs were arched downward, and it just got me curious, but could it be possible to do a spring over conversion and pull a few leaves or so to keep it low enough for 33" tires? Would there be interference with steering components and the frame/oil pan? Just a curious thought, if it could be done, and or things that make it not work. Ha

 

[Torxhead]

There is quite a lot involved for a correctly done s.o.a. conversion. If you are planning on 33s, I would suggest a 4" lift kit to start with.

 

[BusaDave9]

A SOA will raise the jeep 6 inches. That's far too much for 33 inch tires. So removing leaves won't help. I would listen to Torxhead, you'd be better off with a 4 inch lift. If you don't mind doing a little trimming on the rear fenders you can get a smaller lift. You could reinstall the OEM fender flairs and the trimming wouldn't be noticeable.

 

[thescot]

All 80ies Chevy 4x4's have the axles under the springs from the factory. You'd be doing a SUA conversion if you changed it.

 

[bdunnam]

Ha I'm not sure you guys are really catching what I'm saying. I have a 4" lift now, this is just a hypothetical situation. My springs now are arched upwards, in essence giving me lift, what if I theoretically took springs with a downward arch, the middle being the highest point now, and flipped the spring to the top of the axle. Essentially that's how they looked on my chevy and I was curious as far as a jeep goes if it could provide more flex, smoother ride, or any other improvements, or if it's even feasible. I'll try to upload some pics this weekend to help explain.

 

[Jimbos76cj]

I'm pretty sure I get your question and it still makes no sense. I can gel you from experience that every spring I've seen with a downward or negative arch has been worn out of bent. Normally springs when they compress move towards the shackles, forward in the front for example. If the arch was negative it would pull the shackle towards the rear. Also the way springs are stacked shortest to longest helps add strength as the axle is flexed up. If you were to use a normal spring in an upside down fashion all the load would be put on the main spring when it is compressed. Unless the spring pack was built to run in that fashion it wouldn't be good. If you are searching for great flex and a softer ride yj stock springs and soa is about the best you will get. But a lot of steering modification is required because 1) it messes up the geometry really bad and 2) the tie rod will hit the spring. I'm pretty sure the way you describe it would hit the linkage more.

I would love to see pics of these Chevy springs.

 

[bdunnam]

Ha I wasn't really planning on doing it. I have to drive mine every day, I was just looking for other opinions on the subject. But you can actually look it up, after some searching I did scrounge up that some more hardcore off-roaders actually have used the chevy spring, but for me it was just a simple idea and wanted to know what other people thought.

 

[Peanut Butter]

I think I know what you are talking about. Kinda of like a flat bed semi-trailer with no weight on it. They arch up in the middle. I believe this is what Chevy did on older model light duty 4x4s. There are less leaves to the spring this way for a smother ride. Lot of engineering in this setup, may not be practical for a jeep. Rod

 

[Scooter402]

Stock front springs on Chevy's and Fords had negative arch from the factory. This let them ride smooth (well...as smooth as leaves can ride ) and still provide suspension movement.

That being said, if you were so inclined, yes -- you could put some negative-arched springs under your CJ in a SOA configuration and have it perform well. The difficulty comes in with finding springs with the correct rate for your combination. You could try using factory Chevy front springs (either stock or possibly a 2" lift spring) and have it be enough lift for 33" tires. The ride might be a little stiff as the rate on these springs was engineered for full size trucks.

For those reading along this far, no -- I didn't exactly pull those spring height numbers out of my hiney... I do know for a fact that Chevy front 4" lift springs are about the same arch as a stock CJ spring. I have Chevy 4" springs (slightly modified to ride more softly) on the front of my CJ, with stock leaves on the rear, both in a SOA configuration.

Hope this helps.