Topic: Best flexing suspension lift for a YJ?

[jfrabat]

Hey, guys, I am asking this question because I have a firend who wants to change his suspension...  He bought a '94 YJ Sahara (yes, I know, that's a 4.0L, but what can you do, right?) with 4" lift suspension, 1 1/4" lift shackles, and 33" tires.  My friend likes the Jeep, but he thinks the suspension is too stiff, so he wants to change it to something that will flex better than his current system.

What I suggested to him was to get some stock springs and do a SOA conversion, and put some greasable shacles instead of those lift shackles (I dont really like lift shackles all that much!).  I also saw on quadratec that RE has a 1.5" suspension lift spring specifically designed for SOA (the eyes are backwards on those), but I dont know if those will make the suspension harder.

What would you guys recommend?  By the way, he plans on keeping his 33" until they wear out, and then changing to 35", but my recommendation to him was to just change to TJ flares at that time (or a 1" BL if he prefers to go in a different direction).  What do you guys think?  What would be your recommendation for this scenario?

Felipe

[jagular7]

I'll second the SOA, but look at custom length shackles. Keep the length of the shackle matched with the physical length of the leafs. He'll also have to work with the shock length also to make the best of the leaf cycling.

What I'm talking about is the main leaf has a length from eye to eye. This length will be the longest when the spring is flat. Design the length of the shackle to maximize this length during compression and not bind the spring but actually 'swing' with the spring's eye. Do note, the shackle's frame mount location is critical for both compression and extension. You will not want the shackle to point to the axle during full droop/extension. The spring will have a natural tendency to wrap up and pull the shackle under the frame. Once this is done, the spring will bend and lock the shackle against the frame.

[jfrabat]

But if the spring is the stock length (almost flat with the weight of the vehicle), a stock sized shackle (I recommended the Currie Boomerang for the rear and the Currie stock for the front; the front is exactly the same as the stock size, and the rear is only 1/4" longer), there should be no major issues with binding.   Theoretically speaking, as far as the leaf springs are concearned, they will be just like stock, right?  Of course, some new shocks will be needed (any recommendation here?), but the rest should be about the same as a stock jeep...

I know that the brake lines and all that need to be replaced, but since he already has about 5 1/4 inches of lift, he may just reuse all that...

[Jeffy]

Well here's my recommendation since I was in a similar boat years ago.  Go SOA.  BUT you'll want to do all of your homework before hand.  You can easily screw things up if you don't know what you're doing.  Spring perches will have to be setup but you'll have to take into consideration ant driveshaft changes (now or later).  I'm sure his pinion angles are screwed up from driving on those lift shackles.  At least with a SOA he'll be able to correct that.  He'll need a welder, minimum.  Either stick or mig.  Stick will get the job done but not look as pretty.  When welding you'll have to control the heat so the tube doesn't heat up too much and deform any seals in the axle tube.  Short movements with rests for cooling will work.

Brakelines don't have to be replaced.  At least not for the front.  He can reroute the lines for a free 6-7" drop (see faq).  The rear will need to be extended with a new line although I'm sure he's already got extension or something that came with his lift.

Another option is to SOA the front and leave the rear SUA (also in faq).  This will still soften up the suspension while not having to worry about axle wrap and wheel hop.  75-80% of the ride is with the front suspension anyway.  If he went this route, it would only require half the work.

Also, I hope he has removed both trackbars already.  Those things just stiffen the suspension so there is minimal movement.

[jfrabat]

I forgot to mention about the trackbars, but both are removed (as well as the sway bar).  I like the SOA/SUA combination idea...  Seems like the a good option!

[Jeffy]

I forgot to mention about the trackbars, but both are removed (as well as the sway bar).  I like the SOA/SUA combination idea...  Seems like the a good option!

What kind of leafs are they?  I'd suspect stiff leafs with overly tightened shackles/hangers.  Also, if he goes SOA he'll want a sway-bar if he drives on the street much.

[jfrabat]

What kind of leafs are they?  I'd suspect stiff leafs with overly tightened shackles/hangers.  Also, if he goes SOA he'll want a sway-bar if he drives on the street much.

They are a lift kit, but I dont know which one; the Jeep is driven on the street only to get to the trails, but it is not a daily driver...  He has the swaybar discos, so he can put those back in (which I recommended to do), but the trackbar will stay off.

[jagular7]

Here are 2 pics of what I was talking about with the shackles. A fix is to have a wide frame mount that restricts the binding.

[garydubf]

SPOA with stock XJ springs.  Great flex and a Cadillac ride!