Can anyone help me understand shackles and ride height? (1 Viewer)

[Last Flight Out]

I am fairly new to the scene, but have been learning over the past 6 months now on owning an FJ40 and dealing with some of the common problems seen on these beasties. One thing I look for more information on is shackles...and how they relate to ride height. So some questions I have:

1) What is the primary purpose of a standard shackle?
2) What the hell are reverse shackles, how are they different from standard shackles and why do some owners use them?
3) Do shackles determine the actual height setup of an FJ40? General example...if you are looking to raise your rig by 4", you need shackles that are within that desired spec?
4) Finally, do springs have anything to do with ride height? I understand that different spring specs will determine the performance overall, but not sure on ride height.

 

[brian]

1. To provide a flexible mounting position in order to allow the leaf spring to move.
2. Relocating the the shackle mount to the trailing end of the spring....believed to provide a better ride....debatable
3.yes and no....mainly no
4.yes

 

[bikersmurf]

They only lift approx 1/2 the extra length… up to a maximum of about 1-1.5”.

And cause steering alignment issues in the front

 

[B y r o n]

My guess is if you're looking at shackles then you're thinking about adjusting your vehicles ride height for some reason. This could be because of sag in older springs or the desire to run larger tires. If it is because of sag and money is a concern you can correct minor sag with a longer shackle. Understand that doing it this way could lead to handling issues because of the extended length of the shackle. Replacement springs would be a better solution. If you're looking to run larger tires then replacement springs is the better answer. You can purchase a set of springs with the correct lift for clearance without adversely affecting handling.

Shackle reversal is only used in the front and as stated earlier was supposed to improve handling when going over bumps. It also raised the front which required you to raise the rear to remain level. You didn't mention anti-inversion shackles but they are often listed as required for lifted suspensions. Greaseable shackles is self explanatory and can be used in any suspension setup and designed to allow lubing the bushings with disassembly.

Another side note, shackles will not affect the load limit of the springs. In other words they will not increase the load limit of the springs. If your problem is weight related then replacement springs with the needed weight range would be the proper solution.