Front vs Rear shackle.

[Boggin]

What would you suggest and why? I'm kinda set on rear mount shackles but before I burn it all together I'd like to hear others opinions and reasonings.

 

[Boggin]

Was gonna do the front mount like this..

and the rear shackle mount something like this,, with probably some more gusseting and what not.

 

[Captain Ledd]

Rear.

During the spring movement of compression (such as driving over an obstacle), the rear shackle will move backwards. Like a shackle lift (a 2" shackle, lifting the truck 1"), the rearward movement of the shackle allows the axle to move backwards just a little bit as well.

For a front mounted shackle, the shackle movement will try to "push" the tire into the obstacle you're trying to overcome as you drive over it. While most things you can still get over, it's generally agreed that this setup hinders the tires ability to "climb" the obstacle. Not to mention adding a bit of stress to your steering and axle components.

There's also some claims to better drive-ability of a rear mount shackle setup, but there's a lot of factors that influence that.

You are correct in wanting a rear shackle if you have the room.

 

[Boggin]

Rear.

During the spring movement of compression (such as driving over an obstacle), the rear shackle will move backwards. Like a shackle lift (a 2" shackle, lifting the truck 1"), the rearward movement of the shackle allows the axle to move backwards just a little bit as well.

For a front mounted shackle, the shackle movement will try to "push" the tire into the obstacle you're trying to overcome as you drive over it. While most things you can still get over, it's generally agreed that this setup hinders the tires ability to "climb" the obstacle. Not to mention adding a bit of stress to your steering and axle components.

There's also some claims to better drive-ability of a rear mount shackle setup, but there's a lot of factors that influence that.

You are correct in wanting a rear shackle if you have the room.

Thank you sir! I am going to be running a 54" leaf spring so I'm not sure how much room exactly i'm gonna have. i know usually people run Waggy leafs which i think are 46" or 47"? Either way, we'll see what i come up with. I planned to have the axles out of the donor rig by now but with christmas here i've been pretty busy, so probably boxing day ill get at it and then strip down the b2 and plan everything out.

 

[koda6966]

Rear looks cleaner imo.

 

[Boggin]

Rear looks cleaner imo.

This was the main reason I stuck with mounting them at the rear lol. I hate seeing big ass shackles hanging below the bumper on Jeeps


Sent from hell using Tapatalk... on my iphone

 

[legoms013]

I suggest in the rear, easier to slide the vehicle on the leaf, than to push the vehicle into the shackle and cause it to do things it wasn't meant to do.

+1 on the looks cleaner.

Also consider where center of leaf is and where you want the wheel in the fender-well. Then determine if you would rather have the axle swing back, or forward under compression/extension.

Either setup, when built correctly works just about equally fine.....unless you are a hardcore rock crawler then I'd suggest the shackle towards the back.

 

[bobbywalter]

Rear.

During the spring movement of compression (such as driving over an obstacle), the rear shackle will move backwards. Like a shackle lift (a 2" shackle, lifting the truck 1"), the rearward movement of the shackle allows the axle to move backwards just a little bit as well.

For a front mounted shackle, the shackle movement will try to "push" the tire into the obstacle you're trying to overcome as you drive over it. While most things you can still get over, it's generally agreed that this setup hinders the tires ability to "climb" the obstacle. Not to mention adding a bit of stress to your steering and axle components.

There's also some claims to better drive-ability of a rear mount shackle setup, but there's a lot of factors that influence that.

You are correct in wanting a rear shackle if you have the room.

pretty much the way it is

Thank you sir! I am going to be running a 54" leaf spring so I'm not sure how much room exactly i'm gonna have. i know usually people run Waggy leafs which i think are 46" or 47"? Either way, we'll see what i come up with. I planned to have the axles out of the donor rig by now but with christmas here i've been pretty busy, so probably boxing day ill get at it and then strip down the b2 and plan everything out.

but that changes things.

if your staying with rbv powertrain and a 30-44 the waggy springs work out nice.

if you have a combination with 5 in or more shackles and springs that will allow some decent of travel....you really have to pay attention to your front driveshaft setup. i was wasting 1330's and popped the normal slip a few times. and i see it on quite a few other applications i have worked with.



for something that sees allot of road use, watching the actual working angle of the spring is real important along with shackel angle.

big factor is desired ride height.


i prefer to be low as practical for all purpose use.
i like to have the front spring as level as possible, maybe with the front eye a bit lower. with a rbv, this favors a front shackle.


the other option which works good is to let the spring rake up where it will and hang it tight to the frame out front, and put a degree shim on the spring to keep caster in check....finished with a small shackle out back.

i didnt like the ride that way but it works ok and the handling, especially with a trac bar was awesome.. with shorter (say 50 and under) springs its a real good way to go.


with rbv springs or springs over 50 inches...i found it easier to put the shackle out front again to keep ride height in check.

with the spring fairly level and proper shackle angle you can make a nice riding well handling setup. but the total package has to be considered...a dana 60 needs a different rate then a d 30... under hard use the weight of the 60 fawks up the weaker springs fast.



both work...and usually like anything will need some tuning...a track bar really makes the steering tighter.... though generally not needed.

 

[railman]

what he said^^^^^^

originally I was gonna go with a rear shackle....but the stock spring location on the D60 dictated my width....which on my 96 put it partially under the frame....

because of the offset of the frame it was easier to keep the lift lower with the shackle up front...otherwise I would have to do at least a 4" taller front perch to keep my caster/pinion angle in check with the shackle in the rear....

with my springs I was able to move the axle forward 4" and keep it overall lower at the top of the cab with plenty of frame to ground clearance....which was my main goal....

if I have any major issues with the shackle forward ( I really only have one wheelin' trip under my belt and as Bobby said had issues with the front shaft which have been addressed ) I will work through it the best way I know how

l8r, John

 

[Boggin]

pretty much the way it is



but that changes things.

if your staying with rbv powertrain and a 30-44 the waggy springs work out nice.

if you have a combination with 5 in or more shackles and springs that will allow some decent of travel....you really have to pay attention to your front driveshaft setup. i was wasting 1330's and popped the normal slip a few times. and i see it on quite a few other applications i have worked with.



for something that sees allot of road use, watching the actual working angle of the spring is real important along with shackel angle.

big factor is desired ride height.


i prefer to be low as practical for all purpose use.
i like to have the front spring as level as possible, maybe with the front eye a bit lower. with a rbv, this favors a front shackle.


the other option which works good is to let the spring rake up where it will and hang it tight to the frame out front, and put a degree shim on the spring to keep caster in check....finished with a small shackle out back.

i didnt like the ride that way but it works ok and the handling, especially with a trac bar was awesome.. with shorter (say 50 and under) springs its a real good way to go.


with rbv springs or springs over 50 inches...i found it easier to put the shackle out front again to keep ride height in check.

with the spring fairly level and proper shackle angle you can make a nice riding well handling setup. but the total package has to be considered...a dana 60 needs a different rate then a d 30... under hard use the weight of the 60 fawks up the weaker springs fast.



both work...and usually like anything will need some tuning...a track bar really makes the steering tighter.... though generally not needed.

ok man,, thanks. i also thought about the driveshaft slipping out but i figure limit straps maybe? either way the only real way to tell how it will work with 54" springs is to get everything in place and see where it will fall into place the easiest.

what he said^^^^^^

originally I was gonna go with a rear shackle....but the stock spring location on the D60 dictated my width....which on my 96 put it partially under the frame....

because of the offset of the frame it was easier to keep the lift lower with the shackle up front...otherwise I would have to do at least a 4" taller front perch to keep my caster/pinion angle in check with the shackle in the rear....

with my springs I was able to move the axle forward 4" and keep it overall lower at the top of the cab with plenty of frame to ground clearance....which was my main goal....

if I have any major issues with the shackle forward ( I really only have one wheelin' trip under my belt and as Bobby said had issues with the front shaft which have been addressed ) I will work through it the best way I know how

l8r, John

thanks man.. how long are your springs?

 

[railman]

ok man,, thanks. i also thought about the driveshaft slipping out but i figure limit straps maybe? either way the only real way to tell how it will work with 54" springs is to get everything in place and see where it will fall into place the easiest.


thanks man.. how long are your springs?

I lengthened my front shaft and found a longer slip joint....

as for the springs, I dunno the exact length....from a 4 door Ex....

check out my build thread...just posted some "forktruck flex" shots.....

l8r, John

 

[Boggin]

I lengthened my front shaft and found a longer slip joint....

as for the springs, I dunno the exact length....from a 4 door Ex....

check out my build thread...just posted some "forktruck flex" shots.....

l8r, John

ok.. so im guessing the springs im using from a ranger should be pretty close to your setup..

just looked at your flex shots.. i'm really impressed

 

[dieseldane]

Rear.

For a front mounted shackle, the shackle movement will try to "push" the tire into the obstacle you're trying to overcome as you drive over it. While most things you can still get over, it's generally agreed that this setup hinders the tires ability to "climb" the obstacle. Not to mention adding a bit of stress to your steering and axle components.

I had always thought that this was desirable, as it would help push the tires over the obstacle, kinda like when you are trying to "bump" up something.

 

[Captain Ledd]

I had always thought that this was desirable, as it would help push the tires over the obstacle, kinda like when you are trying to "bump" up something.

I'm not so sure. I had imagined it being kinda like spring wrap, and the tire just bounces off. Really it's just shoving the tire into the rock or whatever it is, and it doesn't have quite the same effect as the vehicles own mass/inertia behind it. I was speaking from more of a low speed, crawl over it kind of thing. You can get over almost anything with enough speed

Also to the OP, you could inboard the springs with a rear hangar and add a SUPER stiff sway bar with quick disconnects. probably would give decent enough road manners and allow some serious flex offroad (especially for leaf springs). Then for even more flex combine that with longer shackles now that you have opened up all kinds of room.