The Great Shackle Reversal Debate

[Isotel]

Shackles Reversed or not?

Well I Reversed my Shackles when i originally built my rig.. it tracks down the road good, it wheels fine, but rides harsh (Mostly due to shackle angle and junk shocks)

many of the rigs i wheel with still have the shackles in the front and swear by it reducing front axle wrap, increasing traction in climbing, less unloading on the steep stuff, and preventing the need for a long travel front drive shaft. (Im not Sold on this idea, and want some more opinions on it, i think my rig is pretty stable on climbs)

So Yes SR is great on the road, but now that my rig is more of a crawler and im redoing my front bumper/shackles anyway, what do you think about putting them back in the front of the springs and hard mounting the rear.. It will give me the ability to ditch the square drive shaft and go to a normal CV..

 

[adamsclarke]

On my 1 ton commando (in the for sale section) I went with the reversal. Drives great on road and wheels OK since I run limited up travel.....but...
if I had to do it again...I'd stick with the shackle forward so the axle wouldn't climb away from the truck and would forced back. It also would make the leafs last longer in my case since they were flat leaves...and the reversal really caused them to flex down a ton.

 

[Mace]

Shackles Reversed or not?

Well I Reversed my Shackles when i originally built my rig.. it tracks down the road good, it wheels fine, but rides harsh (Mostly due to shackle angle and junk shocks)

many of the rigs i wheel with still have the shackles in the front and swear by it reducing front axle wrap, increasing traction in climbing, less unloading on the steep stuff, and preventing the need for a long travel front drive shaft. (Im not Sold on this idea, and want some more opinions on it, i think my rig is pretty stable on climbs)

So Yes SR is great on the road, but now that my rig is more of a crawler and im redoing my front bumper/shackles anyway, what do you think about putting them back in the front of the springs and hard mounting the rear.. It will give me the ability to ditch the square drive shaft and go to a normal CV..

SR makes no difference on the road...

It does nothing for axle wrap,

Unloading on the steep stuff?? I doubt it.

The long travel front ds is pretty much necessary for a SR..

On my 1 ton commando (in the for sale section) I went with the reversal. Drives great on road and wheels OK since I run limited up travel.....but...
if I had to do it again...I'd stick with the shackle forward so the axle wouldn't climb away from the truck and would forced back. It also would make the leafs last longer in my case since they were flat leaves...and the reversal really caused them to flex down a ton.

There is no reason why a SR would flex more than a non SR. It is the springs and the orientation of the axle in relation to those springs that makes the difference.



IMHO, the biggest benefit to a SR is the ability to smack you springs against a rock and slide up it without the concern of bending a leaf..
That's about it.

 

[adamsclarke]

SR is definately smoother on the road..as the tire will move back in a natural montion when it hits a bump. I agree, flex really isn;t much different, and it won't unload when climbing steel hills.
But it does make it difficult as the front wants to pull away when climbing an obsticale at low speed..

I ran a 12" slip high angle shaft on mu commando and never had a problem, but even the longest 6" slip on a stock spicer shaft would pull apart. I rn limit straps to keep that from happening again

 

[Tapage]

I'm a happy SR " customer " for more than 6 years .. or so. Definately more smoth on the road .. but I need to recognize ( and maybe it's specific on my setup ) that I miss traction on the hills ..

I'm talking about those 45 degreess with loosy gravel .. or mud, but it's much more present on gravel.

That's a part on the weight tranfer due to the LWB of Tencha and usually when I go out for a trip do it heavy loaded at back ..

Anycase if I need to choose I will do it again ( SR ) ..

 

[Mace]

SR is definately smoother on the road..as the tire will move back in a natural montion when it hits a bump. I agree, flex really isn;t much different, and it won't unload when climbing steel hills.
But it does make it difficult as the front wants to pull away when climbing an obsticale at low speed..

in a spring over system, with standard flat stock springs, the tire will move forward in a SR arrangement..

 

[Isotel]

my front springs are nice and flat.

this is a good read - http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=260281

thanks for the opinions guys!

 

[Sputnik40]

After nearly ripping off the passenger side shackle hanger and part of the frame with it - I'd never go back to a front shackle. My SR has it's problems - mostly limited clearance for the draglink due to being low profile - but it's worked very nicely over the years.

 

[bustanutley]

Bending springs and clearance at the front of the truck is really the largest concern, there isn’t enough of a difference in performance to switch it up unless you link it up. SR makes it easier to build the truck lower. I really hate how I get hung up the shackles in my SR if I have to back up, however my shackles are below the frame since the springs are outboarded. If you want to control wrap in the front, figure out how to rig your winch to pull strait up on the axle and attach it to the third.

 

[mookie]

i hate the way my front shackles freaking hit everything and stop me cold.....if i wasn't planning on linking the front soon i'd have reversed them a long time ago

 

[Uncle Ben]

Ahhhhh the old SR vrs FS debate....nearly as timeless as SO/SU.... I like SR as they do tend to make a trail rig drive better on hard pack especially rutted roads. The reason is off highway is really tough on spring bushings. The inherent slop which is a byproduct of actually wheelin' your junk causes the steering end of the spring to deflect with input from both the driver and the road. Shackles front will have in theory twice as much "slop" as the fixed pivot end. Move the fixed end to the front steering side of the spring and let the sloppy end follow. The age old argument of rock finders is just pooh.....you can drive home on a bent hanger but a bent spring will require some thought to get it safely home. (plate the hanger and laugh at the rock hit instead....can't plate a shackle/spring end! deflection rearward vrs pushing into a rock is also pooh as they both have their own benefits. rearward travel allows the rear tires to continue to move forward all the while the front tire is climbing....pushing forward stalls the rear tire movement and actually pushes it backwards while the front climbs. Not rocket science.....same end result just stresses in different places. If you like spirited driving once in a while and there has been those times when your junk takes flight you will appreciate landing on rearward moving wheels rather than bending those springs back! Flame away....

 

[Mace]

Ahhhhh the old SR vrs FS debate....nearly as timeless as SO/SU.... I like SR as they do tend to make a trail rig drive better on hard pack especially rutted roads. The reason is off highway is really tough on spring bushings. The inherent slop which is a byproduct of actually wheelin' your junk causes the steering end of the spring to deflect with input from both the driver and the road. Shackles front will have in theory twice as much "slop" as the fixed pivot end. Move the fixed end to the front steering side of the spring and let the sloppy end follow. The age old argument of rock finders is just pooh.....you can drive home on a bent hanger but a bent spring will require some thought to get it safely home. (plate the hanger and laugh at the rock hit instead....can't plate a shackle/spring end! deflection rearward vrs pushing into a rock is also pooh as they both have their own benefits. rearward travel allows the rear tires to continue to move forward all the while the front tire is climbing....pushing forward stalls the rear tire movement and actually pushes it backwards while the front climbs. Not rocket science.....same end result just stresses in different places. If you like spirited driving once in a while and there has been those times when your junk takes flight you will appreciate landing on rearward moving wheels rather than bending those springs back! Flame away....

huh.. So, do you like them or not?

 

[Tapage]

huh.. So, do you like them or not?

thought yes ..

 

[Uncle Ben]

huh.. So, do you like them or not?

Yes! My bad.....I obviously am bored at work and am looking for any excuse to do something else.....

 

[adamsclarke]

in a spring over system, with standard flat stock springs, the tire will move forward in a SR arrangement..

In a SOA with SR, the wheel will move back on compression and forward on droop.
The moving back is what smooths out the bumps on the road, but cause the tire to get into the fender more near the door.

 

[Mace]

In a SOA with SR, the wheel will move back on compression and forward on droop.
The moving back is what smooths out the bumps on the road, but cause the tire to get into the fender more near the door.

How. If the spring is flat (typical SO on stock springs) with a SR the fixed point is on the front of the bumper. So, as the spring either compresses or extends the tire moves towards the fixed point.

You can't have it go both ways, unless you have arch left in your springs.. Which is easily remedied by wheeling a springover

Neg arch does an awesome job of flattening a spring..

 

[xjnation]

With a flat spring as in SOA, the axle will basically move in an arch from the fixed point. Front shackles, hit a bump and the rear of the spring does not stretch. It will arc up and back, and down and back. SR it and it does the opposite.

With SUA or anything with an arch in the spring it will change because the arch allows the length from the axle to the fixed point to change as the spring flattens or arcs more. Shackles in the front the wheel will travel up and foward, down and rearward. I think that suas benefit more from SR for ride quality, but they are also lower and more prone to the "rock finder" syndrome.

SOA with stock length shackles are fine by me. if you are worried about bending springs you might oughta (that sounds redneck) practice picking your lines .

**edit** That's exactly what Mace just said, isn't it?

 

[Isotel]

So you guys are all saying just Link it up and get some coil overs ??


i think ill keep it the way it is, Build some new hangers into my new bumper, and put the Shackles through the frame, 45 degress or so.. then maybe some Center Limit Straps front and rear to keep it grounded on climbs and drops..

 

[Mace]

See if you can make the winch work to hold your front axle when you want to do full throttle assults on hills

 

[Isotel]

sounds like an idea, i need to figure out a good way to do that, Synthetic wont mind pulling around an outside radius of tube will it?

down to the axle, trough a Pulley, then back up to a point above the axle. (need to build a cross member between the motor mounts, under the oil pan)