Check my shackle angle. [Archive]

jagular7

11-04-2009, 08:06 PM

If you get a longer shackle, it would provide lift based on frame mount and length of leaf.

To figure if you have enough shackle length, use a piece of string. Tie a knot at an end and tape it to the bolt at the front of the leaf. Let the string follow the curvature of the main leaf to the other eye end. Tie another knot. Hold that there on the bolt head, take the rest of the string and bring it up to the shackle bolt on the frame mount. Tie another knot and tape it there. Now, slightly pull on the free knot (end of the leaf) so that the string representing the main leaf gets to be straight. If you pull the knot off the shackle before having a flat string, the shackle is too short and it will bind the leaf during its cycle. The main leaf will cycle from concave, to flat, to convex. The leaf is its longest at being flat. If the shackle can not swing with the leaf when it is flat, then it binds.

Now if you restrict the compression enough to limit the cycle, you have to determine where you stop the cycle and where the shackle will be wrt the main leaf.

For the droop aspect, you have to determine if the shackle will bind the rear portion of the main leaf. You don't want the shackle to move forward of the rear leaf eye. It will bend the leaf and you will need a new leaf or leaf pack. Take the same string, tie a knot where the main leaf is at the center of the axle. Put the string under the axle to get the droop aspect of the axle. Tape the knots at the frame mounts. Pull directly down on the center knot. The front portion of the string will be rigid so make that as best you can. The shackle should not point directly to the center knot. If should point to a spot behind the axle (short of the axle). This angle will keep the shackle from swinging too far forward and then locking itself against the frame resulting in binding the main leaf. There will be some axle wrap so try to keep that shacke pointing as far back as possible.

Now all this is done with a string. Leafs have different materials, thicknesses, widths, twisting capabilities, etc. Spot your frame mounts in place, add your main leaf and spacer (represents the other leafs in the pack but they are not necessary for determining static locations of the mounts and shackle length) and tire and twist it up. Atthis time, you can measure for shock length as well. What is nice about a leaf suspension for droop, there is a natural binding from the leafs, so basically, you can get longer shocks and they won't be your axle retainer.....


Pirate4x4.Com > Brand Specific Tech > Jeep - Non Hardcore > Check my shackle angle. PDA : Check my shackle angle. ox locked 11-04-2009, 07:09 AM How does my shackle angle look? I still need to add corner guards and top off the gas tank but for the most part it has all the weight on it. http://lh5.ggpht.com/_oxnkV42FIIQ/SvGU5N07CiI/AAAAAAAABmQ/uWQl82q_iOY/s640/DSC01872.JPG http://lh4.ggpht.com/_oxnkV42FIIQ/SvGU8iaYffI/AAAAAAAABmY/V_X5Qr9YL4A/s640/DSC01874.JPG Grind 11-04-2009, 07:13 AM Looks fine to me, run it! 2003_ram 11-04-2009, 07:35 AM Looks fine! Go Beat your Jeep! 1977 11-04-2009, 07:03 PM If they are flat springs the angle is good. If they have an arc which it looks like they might, not sure you have enough swing in the shackle to allow the springs to grow when they compress. Makes for a harsh ride. Will get nice droop though. The Black Sheep 11-04-2009, 07:13 PM If they are flat springs the angle is good. If they have an arc which it looks like they might, not sure you have enough swing in the shackle to allow the springs to grow when they compress. Makes for a harsh ride. Will get nice droop though. This. Your shackle angle is maxed in terms of compression if the spring has an arch to it. If not then you are good to go and it should flex nicely. jagular7 11-04-2009, 08:06 PM If you get a longer shackle, it would provide lift based on frame mount and length of leaf. To figure if you have enough shackle length, use a piece of string. Tie a knot at an end and tape it to the bolt at the front of the leaf. Let the string follow the curvature of the main leaf to the other eye end. Tie another knot. Hold that there on the bolt head, take the rest of the string and bring it up to the shackle bolt on the frame mount. Tie another knot and tape it there. Now, slightly pull on the free knot (end of the leaf) so that the string representing the main leaf gets to be straight. If you pull the knot off the shackle before having a flat string, the shackle is too short and it will bind the leaf during its cycle. The main leaf will cycle from concave, to flat, to convex. The leaf is its longest at being flat. If the shackle can not swing with the leaf when it is flat, then it binds. Now if you restrict the compression enough to limit the cycle, you have to determine where you stop the cycle and where the shackle will be wrt the main leaf. For the droop aspect, you have to determine if the shackle will bind the rear portion of the main leaf. You don't want the shackle to move forward of the rear leaf eye. It will bend the leaf and you will need a new leaf or leaf pack. Take the same string, tie a knot where the main leaf is at the center of the axle. Put the string under the axle to get the droop aspect of the axle. Tape the knots at the frame mounts. Pull directly down on the center knot. The front portion of the string will be rigid so make that as best you can. The shackle should not point directly to the center knot. If should point to a spot behind the axle (short of the axle). This angle will keep the shackle from swinging too far forward and then locking itself against the frame resulting in binding the main leaf. There will be some axle wrap so try to keep that shacke pointing as far back as possible. Now all this is done with a string. Leafs have different materials, thicknesses, widths, twisting capabilities, etc. Spot your frame mounts in place, add your main leaf and spacer (represents the other leafs in the pack but they are not necessary for determining static locations of the mounts and shackle length) and tire and twist it up. Atthis time, you can measure for shock length as well. What is nice about a leaf suspension for droop, there is a natural binding from the leafs, so basically, you can get longer shocks and they won't be your axle retainer.....