I read I think on the AEV site that you can use stock TJ front springs to level the front of the JK with a bumper and winch. I have a AEV front bumper and will soon have a winch and I know it is going to sag the front of my 4 door rubicon. I have some stock TJ springs and am woundering if anybody else has any experience using TJ springs in their JK.

 

Stock TJ springs??

 

I guess it could work. I guess. But why go to all the trouble if it won't? Springs aren't too expensive. I would get the right ones if it was mine.

 

To level the jk, it would need to bring the frt up about an inch, comparing my stock springs to my wifes TJ springs, it just doesn't look like it would, I could be wrong though, since the straight 6 might be heavier than the v6.

 

A buddy of mine told me that the front springs of a TJ would lift the JK 1" but I have no proof

 

Now that I think about it, the front of a TJ, with the heavier hood and fenders added to the inline 6, they may be able to lift it.

 

here are some quotes on AEV's website.

"The AEV Front Bumper, Winch, Skidplate and lights will drop the front of your JK about 0.75-1".

Using a STOCK 4.0L TJ spring will give you a 1" lift on a JK. The other advantage of this technique over a spacer is that the TJ spring will give you almost the perfect spring rate (higher) to deal with the added weight of the bumper which will be noticeable in abrupt maneuvers and hard braking as well as fast off-road driving.

dh

Well actually lax22 is on the right track. Each 'family' of factory springs - such as the fronts for TJ's - is designed so that it carries it's target load at the same height and gives roughly the same ride frequency - which means the heavier the target load, the higher the spring rate will be. So when using them on a JK that's gained a bunch of weight in the front, the effects are the same. The question is (and I don't know the answer myself), which TJ spring happens to be correct for the new load of the JK's front end...and does it give the desired height with that new weight? With all the numbers laid out I could determine the right answer, but in general a TJ spring designed for the same load as a JK happens to be will give it a 1.0" lift because the design height is that much taller. If a given TJ spring generates more lift than that, the JK is actually lighter than the TJ the springs came from, and vice-versa. Since the TJ is designed to have a higher ride frequency than a JK was from the factory, the spring rate even at an on-target height of +1.0" will make the JK feel a little 'stiffer' than the stock setup did...which probably isn't a bad thing given the spongy stock JK setup...and at least it will add understeer rather than switch it to unsafe oversteer. So what TJ spring to use? Good question! I'd guess that the heavier TJ springs such as from a Rubicon will be the best, but all of this mixing and matching is a crapshoot until you have the right numbers and equations...so you'll just have to go with "does it look/feel right" until a downtown study is done...and I'm not sure I'll manage to get around to that anytime soon!

Jim"

So it seems the stock TJ spring gives about 1" of lift and a higer spring rate which will help with the heavier front end. from winch, bumper, and possibly AEV hood. all that weight adds up on the spongy stock JK spring. and we get alot of sag. Being that I my offroading is of the overlanding style I have no use for 35" tires and 4" lift. stock ride height is fine for me. But I would like to level out the ride and get rid of the squishy feel. Heck the TJ springs are free. and seem to be recomended By AEV engineers for teh JK. Just woundering if anybody else had heard of this, and had any experience actually doing it.

 

Not trying to argue the point, but I would be careful about blanket statements like that from AEV. There's NO way they can say that using stock TJ springs will lift a JK 1" in the front. My Jeep sat 2" down in the nose when it was new. I've seen others sit level. The point is, there are so MANY different spring rates for the JK.....just as many I bet for the TJ. So, the only way the TJ springs could lift every JK up 1" in the front is if ALL JKs had the same rate springs, and this is far from true. I reiterate. I would be careful.

 

1.5" for me on a bone stock vehicle. Redneck has a good point!