Off Roading Forums banner

YJ conversion, Drop link or rev schackle?

924 views 9 replies 4 participants last post by  lilzeus 
G
#1 ·
I will be doing a yj spring conversion and am not sure if I should go with a drop link schackle or do a reverse schackle? I am working with a bare frame now so my acess will never be greater. What are your opinions on which is better? Should the front be the same set up as the rear or can there be one of each. Any good sites or picture will be appreciated. (have danny L's)Thanks for the info.

Don't force it, just get a bigger hammer.
 
G
#3 ·
I have Missing Links in back and a shackle reversal in front with my YJs (I have the Canyon State kit) and believe me, the springs are not the limiting factor in wheel travel; it's the driveshafts. Even the AAPA super-long-travel driveshafts are close to their U-joint angle limit under full droop despite the clearanced flanges. I come within a hair's breadth of binding up my front driveshaft, and I seriously munched my stock rear driveshaft on the Rubicon, binding up the joint and bending the yokes. Ouch.

So if you do go with Missing Links up front with the YJ's, you better plan on getting a serious driveshaft. We're talking about a double-cardan joint on the t-case end. The good thing about that type of shackle configuration is that you won't need quite as much slip yoke travel since you wont' have the shackle reversal's suspension geometry. But you will probably need a Panhard Bar to be able to control the front axle slop if you don't do the shackle reversal.

I'd suggest talking with Trail Tough. They have a missing link front YJ setup now so I'm sure they could give you all the info you need. Personally, I prefer having the shackle reversal after my experience with both the standard configuration with missing links and then upgrading to the SR. It's simpler, rides smoother, works better off-road (both at high speeds and at rockcrawling) and doesn't need a panhard bar.

-- Geoff Beasley

 
#5 ·
I'm taking the other road, I'm going missing links in the front Cuz' I already have $900 worth of drive shafts under my rig. The front being a Trail Tough birfield with a extended slip yoke. I do run a Calmini shackle reverse in the front now, so going to missing link will make the old girl a little hard to handle on the road.....but she's not a daily driver anymore. I'll get the kit ordered and on the truck and let you know what I think.

88 Zuk
locked and loaded
http://www.zukin.homestead.com/main.html
 
#6 ·
I am not running the yj springs but I use to run the M/L and I did not like them. I mostly climb mountain though. I fabbed my own shackle reversal and I love it. It is stable, both on road and off. Going up hills is great now. The only draw back so far is driveshaft length and during axle compression my tires hit the fender wall.

Marc Haught
marcushaught@msn.com
www.serioussami.rockcrawler.com
 
#7 ·
I have the same set up as Geoff also, and love it. but also have the same problem with driveshafts. My rear D-Shaft binds up and the double cardan is shot from the droop. Next up is a Arizona Drive line rear Double Cardan with 40* of droop, but for $360 :-( gotta start saving

 
G
#8 ·
I agree with Zukiman about the smoother ride with SR although mine is the Calmini kit (training wheels compared to his). The advertised advantage being that the axle swings back from the fixed front so it soaks up impacts easier.

Here's another angle that I picked up from Brent at Trail Tough. I'm getting ready to do something also and have been researching me azz off about all the options. This time it's a hypothosized downside having to do with torque's effect on the axle. When climbing, rotational torque applied from the tires causes the axle to rotate back causing the shackle to extend... If you're very nose high, it could tend to make you see God. /wwwthreads_images/icons/shocked.gif The flip side of course is going down hill and applying brakes or hitting bumps, the front end is going to nose over. Mine does this when smashing the brakes on the street more than it did before. The difference now would be that with the YJ soft, flexy setup that we're looking for, it would be much more exagerated.

These are his words and experiences. He was, or is running a YJ SR setup for at least the last year. But the physics ring true. Now if we can get some of the other folks to comment it would be reeeelllyyy interesting... pro or con. And yes, he is releasing, this week, a YJ spring setup - not shackle reverse.

Gentlemen, lock and load! Wahoooooo.... /wwwthreads_images/icons/crazy.gif

Scott

87 Teal Hardtop - Calmini SR, 235 BFG/AT's, GRS2, Weber, Thorley, Flowmaster, RRO Crawler Rear that likes to eat Camry's :+>
Semper Fi!
 
G
#9 ·
Addendum.

Got to thinking some more and forgot to give a couple of other advantages to SR. Many say that it's easier to get a tire up, say on a ledge or over a rock than it is with a normal setup. Also, and I'm not sure about this, there may be a better approach angle even with the required 3" frame extension. Also #3, another 1.5" of wheelbase over the shackle forward and especially with the 46" long YJ springs. Enough has been said about the $$$ driveshafts I think.

Having spouted all of that drivel, I'm leaning towards the CJ's in the rear with my rears shackle forward and missing links all around and I'll get a panhard bar when I can. Hey, I've still got to do diff gears, get locked up some way and buy me some bigger meats, so bucks fer driveshafts might be just a little too much to chew on.

My two bits worth. Please chime in!
Scott

87 Teal Hardtop - Calmini SR, 235 BFG/AT's, GRS2, Weber, Thorley, Flowmaster, RRO Crawler Rear that likes to eat Camry's :+>
Semper Fi!
 
G
#10 ·
Good choice. I ran shackle reverse and I dont know where these guys get their opinions on them. I made a post not long ago explaining that if you run fairly flat leaf springs, you dont gain squat from a s/r. S/R's are a good idea if you have leaf springs with a LOT of arch, then you can take advantage of the movement of the axle when you compress them. Otherwise, you dont gain much over having the shackles up front. As you can see, guys with the s/r's have to invest some serious cash into driveshafts, and even then they are marginal. I didnt have nearly the same flex with my s/r when I had it, and the driveshaft angles were so bad that the yoke would smack the tranny crossmember and it eventually smacked a hole in it. Another thing I dont like about the s/r kits for Wrangler springs is that they put the springs, and in turn the axle, at such an angle that its kinda silly. The rear part of the spring eye is either level with, or slightly below the axle housing, while the front spring eye is above. Most guys run a flat spring when they go spring over because you get plenty of lift. so what is the underlying reason for going S/R? The whole principle behind it was that 'when your tire hits a rock and the suspension compresses to go over the rock, your axle will move in a rearward direction, which is a more natural movement for getting over the rock'. Its important to note that this principle is only relevant for COMPRESSION, not droop. With droop, the leaf spring is essentially static, that is, its not bending much or encountering some kind of force other than the weight of the axle itself. Certainly, the leaf spring gets and arch in it when it encounters droop, we all know that. So the advantage of being either way, s/r or regular, is nil. In both cases, the axle is 'swinging' from the fixed point. I really dont see an advantage for either way.

ICQ# = 3859170
There's a new Sami website in town, and its...
http://members.home.net/micahis
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top