Shacle Reversal

[4x4fEvEr]

This desrves its own thread.

Who's got one?

My reason for wanting one is to help keep my front springs from bending. As you know a reversal pushes the axle back as u hit an obstacle and standard shackles push forward which with he tires pushin too equals a lot of stress on the rear of the springs. So good idea to do it right?
I'm ruunin stock springs with AAL right now does that net the same lift as shackles forward?
I need some input

[4x4fEvEr]

Ok trasborgs article says it keeps the leaves from bending but for rockcrawling leave em forward, but Cappa did it to hotdog hmmmm

[j20brett]

The only reason to leave them forward is that it forces the leaves into the obstacle, instead of away, making it easier to climb. But the advantage of not bending leaves anymore far outweighs a small climbing advantage.

[4x4fEvEr]

This is true. I'm finding all kinds of articles for them but none apply to fsj's

[fulsizjeep]

Our 76 Waggy with SOA has the front shackles reversed and it flexes like an Olympic gymnast. :thumbsup: It was set up this way when we got it so I am not sure what all was done in the reversal process.

[Long&Low]

I ran a shackle reversal on my YJ. It allows the spring and axle to climb stepped obstacles better.

But there is a down side or two. First the axle will have move fore and axle movement, so you may end up needing a longer splined area for your front driveshaft. Mine needed a 12" slip joint. That gets kind of spendy, unless you want to run a squate tubed front driveshaft. With that extra for and aft movement, you may run into the tire coming up and into the rear of the fender during the lift cycle. And as it cycles down, the axle will move farther forward.

As for street driving, under hard braking, your nost will dive down.

All in all it's six of one, half dozen of the other. A lot goes into how you set up the spring. Do you make your front mount higher or leave it level (level as in parallel to the ground)? You can dial in how the spring will react on obstacles if you place it differently.

It really doesn't matter if it's a baby Jeep or FSJ, the charateristics will be the same.

[j20brett]

Our 76 Waggy with SOA has the front shackles reversed and it flexes like an Olympic gymnast. :thumbsup: It was set up this way when we got it so I am not sure what all was done in the reversal process.

Could you possibly take a few pics of the front and rear hangers? Thanks!

[fulsizjeep]

Sure, when I feel like laying in the snow again. ;)
The spring hangers are stock. The only thing that changed on the springs was the shackle move to the rear.
The front shaft is longer than stock and has longer yoke section to help with axle moving back when compressed.

[4x4fEvEr]

The only thing I care about is bending springs and trasborg says in steep climbs the front end wanders. I dontlike that.

I'm ruunin a square shaft already and I don't care about bodydamage there's not a straight dent free panel on mine and I don't run on the road so all those concerns are out the window.

I'd like to see pics as well seen a rough country kit for $110 bucks I may get that and have at it

[fulsizjeep]

The only thing I care about is bending springs and trasborg says in steep climbs the front end wanders.It wanders more on the pavement than anywhere else. We got used to it. It is fun to get someone riding shot gun in it for the first time. ;)

[jtr]

I am going to save my $$ and 3 link front and some kind of link setup in the rear. Early Bronco springs would work good in the front I think.


Leafs just arn't going to last long for your application, IMO.

[Elliott]

These guys (members here) have a SR kit for FSJs: http://www.tandjperformance.com/main.shtml

[4x4fEvEr]

Leafs just arn't going to last long for your application, IMO.

Yea tru links and coils would be great. Not even in the budget though

[Long&Low]

The only thing I care about is bending springs and trasborg says in steep climbs the front end wanders. I dontlike that.

I'm ruunin a square shaft already and I don't care about bodydamage there's not a straight dent free panel on mine and I don't run on the road so all those concerns are out the window.

I'd like to see pics as well seen a rough country kit for $110 bucks I may get that and have at it

Tell Pete you'll get less wandering with an SRS system than without, hillclimbing or not.

[Stuka]

It should also be noted that your front drive shaft will be forced to operate at a much higher angle when the axle droops. As the pinion will point down instead of up (as it does with a front shackle). So you look fine for slippage with the square shaft, but the u-joints are going to need more angle (unless you already have 1410's or the like).

And, if you drive on the street, you will get a lot of nose dive when you brake hard as when the axle pushed back, the shackle will give, which allows the axle to move up as well.

[Dmntxn77]

When flexing now, your pinion gets pointed towards your transfercase. When flexing with a shackle reversal, your pinion gets pointed towards the ground.

You will need to make sure that your drivelines can handle the extra angle.

You can rotate the leaf perches around the axle a little bit, but that is a lot of work for anyone who is already spring over. Plus, I wouldnt reccomend cheating it more than 2 degrees anyway otherwise it will wander like a yaht at higher speeds.

[Dmntxn77]

I guess I type too slow... Stuka beat me to it...

[Dmntxn77]

Anther point to cover is axle movement withing the wheelwell. Stock, the tire sits closer to the firewall than it does the bumper since it will move forward during flex. Once you switch the shackle, your axle will move the opposite direction. So, you will probably need to reposition your axle closer to the bumper so that when you flex, it does not get forced into the firewall.

[4x4fEvEr]

Good points! I have a 1410 yoke for the front but no driveshaft yoke I gotta find one, and I could turn mine up 2 degrees no problem plus I'm already highpinion so I think ill be safe. I've got the front axle pushed forward two inches as is it was eating into my turn signals which are gone now so I should be fine if not I can always make room. I'm def going to do the shackle reversal

[Dmntxn77]

Cool, go for it...


If I were you though, I would measure your pinion angle at full flex just be be sure. Remember, the HP D60 pinion location is only 2.25"s higher than the LP D60, so its not THAT big of a difference. It still doesnt point your pinion up.

[fulsizjeep]

http://jubileejeeps.org/tech/soaluna/banner.jpg

more pictures underneath here:
http://jubileejeeps.org/tech/soaluna/index.htm

[JeepsAndGuns]

From the looks of it. It looks like they simply took the stock shackle off the front, bolted the spring to the stock hanger, and then stuck the shackle on the rear hanger.

[Dmntxn77]

Flint, do you have any side profile pics that show your at rest pinon angle?

[fulsizjeep]

Flint, do you have any side profile pics that show your at rest pinon angle?not yet, but can get a couple this weekend

[j20brett]

Thanks for the pics flint!

[AlsChopShop]

so they just put the shackle on the other end. they must have adjusted the SOA perches for the severe increase in caster..... or.... maybe that's why its so scary to drive. ;)

Al

[JeepsAndGuns]

so they just put the shackle on the other end. they must have adjusted the SOA perches for the severe increase in caster..... or.... maybe that's why its so scary to drive. ;)

Al

Ya know, I was thinking the same thing. Weather or not they did this before or after the SOA, and weather or not they did anything to correct it. If this is in fact the way they did it. Because like you said, that could be why it is so squirly to drive.

[guishe]

http://i180.photobucket.com/albums/x15/nanu_detalles/ChasisReverseShackle02.jpg
I dont know much about this little things. I just like to read.
And also like to draw, so I guess that if you want to reverse the shackle and keep the original caster and angle of the springs, you should add something like the red piece in the picture.
Axle will go about 1.5" forward, and you will add about 2" high at the same time.

[Dmntxn77]

Nice work... BUT, you would want that shackle facing 30 or so degree back, not forward...

[guishe]

AS I said... I dont know a lot ... but i'm in the same process you are... and I found a lot of articles in which the set up the shackle angle to the front... here is a couple... (in the second, look at the movement in the spring). They are not talking about fsj, but I think it should be the same.
In case you are right, changing the angle wont change the high, just the "forward movement" (it would be "backward") And excuse the posible grammatical mistakes my english is kinda primitive

http://www.4wheeloffroad.com/techarticles/drivetrain/131_0902_jeep_leaf_springs_shackle_reversal/photo_06.html

http://jeep.off-road.com:80/jeep/data/articlestandard/jeep/512005/260281/rarch2.jpg

[Dmntxn77]

Yeah, I can picture it working either way I guess.. It seems that with the shackle forward, you would be at risk of getting it pinned forward when recovering from a droop condition...

Dunno really... Ive never done one, but in my head, it seems that facing back would be the better option...

[guishe]

I think that the arch in the springs counts... in the images I have with flat springs, the shacles is at 0°, or "negative" (as in the pictures from fulsizejeep, which are just as you mention).
With lift springs (4" or more) I´ve seen as in my draw. But I dont know if they could go flat forward as you said. Perhaps a more conservative angle would work better. With so many opinions in this issue, seems difficult to find a definitive word about this question.

[fulsizjeep]

better view of shackle and pinion angle

http://jubileejeeps.org/tech/soaluna/pinionangle.jpg

[j20brett]

Wow not much compression travel there eh? ever have probles with it bottoming out?

[Dmntxn77]

:eek:

Yep Flint, that accounts for the scary handling... Your caster and camber are probably WAY off.

[j20brett]

:eek:

Yep Flint, that accounts for the scary handling... Your caster and camber are probably WAY off.

Nah looks to me like the c's were cut and rotated to correct that. i think its the lack of steering correction that make his handling bad. No DPA or highsteer to correct it.

[C. Boyer]

From the looks of it. It looks like they simply took the stock shackle off the front, bolted the spring to the stock hanger, and then stuck the shackle on the rear hanger.

That's what I did and the smoothness is insane. Remove the front driveshaft and have it fabricated so it doesnen't bottom out. I did that too. You have to measure the compression and droop, NOT JUST YOKE TO YOKE. The 78 has 12-14 inches of wheel travel so you may have to cut the rear of the front fender a little bit. It drives strait as an arrow, on and of road. Through whoops it's in an insane difference! :fsj: :thumbsup:

Whatever you're into:cool:

[4x4fEvEr]

I'm getting a kit for a yj to put on mine hopefully be able to start it in two weeks. I read in petersens this month on a shackle flip to set the rear shackle at 60degrees with no weight on if course

[fulsizjeep]

Well, thanks to this exercise, I realized that drive shaft is too long. I did not notice until I resized the picture. We have not put this one through too much difficult terrain but had never heard or felt it bottom out. Something else to change when the QT & adapter get changed out this spring. We have some rocks here I can exercise it on and see how much travel there is to the rear. The drive shaft was new in 2003. The C were rotated but I don't know how much.

[guishe]

I read in petersens this month on a shackle flip to set the rear shackle at 60degrees with no weight on if course

It seems that this answers the question of the 30 degrees forward/backwards? ... the shackle is set in the position I mention without weight, whit springs extended; and then with the weight as the springs get a bit compressed. the shackle goes backwards, as you said...

[rustywagoneers_com]

That's what I did and the smoothness is insane. Remove the front driveshaft and have it fabricated so it doesnen't bottom out. I did that too. You have to measure the compression and droop, NOT JUST YOKE TO YOKE. The 78 has 12-14 inches of wheel travel so you may have to cut the rear of the front fender a little bit. It drives strait as an arrow, on and of road. Through whoops it's in an insane difference! :fsj: :thumbsup:

Whatever you're into:cool:

Pics?

[Dmntxn77]

Well, thanks to this exercise, I realized that drive shaft is too long. I did not notice until I resized the picture. We have not put this one through too much difficult terrain but had never heard or felt it bottom out. Something else to change when the QT & adapter get changed out this spring. We have some rocks here I can exercise it on and see how much travel there is to the rear. The drive shaft was new in 2003. The C were rotated but I don't know how much.


Yep, now that its pointed out, I see that your knuckles seem to have proper orientation.

I would guess that your pinon has been rotated up 10-15 degrees. If I could access photobucket at work, I would post a pic for you of mine that has been rotated up 12 degrees...

Eitherway, that leaves you with quite the desirable axle there!!

[AlsChopShop]

It seems that this answers the question of the 30 degrees forward/backwards? ... the shackle is set in the position I mention without weight, whit springs extended; and then with the weight as the springs get a bit compressed. the shackle goes backwards, as you said...
yes... that's what they are doing in the first article that was posted. with no weight the shackle is forward, but with weight it will move back.

look how the toyota guys do it... shackle backwards. if your shackle is forwards it puts a lot more force on the shackle and its mounting point as the spring extends in length. its working against itself.

Al

[4x4fEvEr]

So in a fsj do you want them forward or backwards using springs with some arch?

[guishe]

So in a fsj do you want them forward or backwards using springs with some arch?

Install them looking fordward while the rig is lifted (no weight).
They will go backwards when you drop the weight on the floor, but they should still have more "travel" backwards to let the springs extend when under compresion

[4x4fEvEr]

30 degrees pointed towards the front bumper

[AlsChopShop]

30 degrees pointed towards the front bumperi wouldn't say that is a set rule. it depends on your spring rates and arch to say how much compression (lengthening) the spring will do with full weight on it.

its not an exact science, a buddy of mine did a SAS on his pathfinder, and had to relocate his spring hangers multiple times to get his shackle where he wanted it.

Al

[AlsChopShop]

here's an example of one. forward when it hangs, but it will face rearward after the weight is on it.

http://eagle.bsd.st/%7Edertow/images/truck/newfrontsprings/newsprings11.JPG