Question about Shackles

This 70 CJ came with longer aftermarket shackles from the PO. They are a little over 6 inches from center hole to center hole. Anyone know what brand these are, and if you think they are bordering on being too long?

I only run 31s, so I have more clearance than necessary and would not be concerned to reduce the height a little. Additionally, always looking for a way to improve handling, although its really pretty good considering. I am running a modified Ross set-up, using the ross box and linkage to the bell-crank, but have a solid, one piece tie rod and drag link to the knuckles (also PO - much like a Saginaw set-up with tie rod and drank link). The extra height from the shackles combined with the high bellcrank location creates some front draglink angle and causes some bump-steer (one advantage of a sloppy ross box is the bump steer is minimized ) Long-term would be nice to replace Ross with manual Saginaw but that is kind of down the line and this Ross setup works well enough for now I think.

Just looking for some feedback including suggestions on better or replacement options. This is kind of long term planning and expense estimates as I continue to improve(?) it piece by piece.

thanks

 

I worry about the side to side stress on the mounts as well - no damage that I can see...yet. It does have shims under axle to help keep castor issues minimized.

What was stock shackle length for these ECJ5s? 3 inches bolt to bolt? I think a 4 or 4.5 inch shackle would work well - give just a small boost to help with clearance but not cause too much problem.

Wondering if reducing shackle length would cause any problems with current steering - would the drag link be too long then and uncenter the steering?

 

Anyone know about these MORE 4.5 inch shackles?

http://www.quadratec.com/products/12590_300X_PG.htm

 

Revisiting my post here - thanks for the input all. I intend to go to a shorter shackle on the front - probably about 4.5 inches bolt to bolt on the front. As I understand, shortening the shackle 1.5 inches will reduce lift by about 0.75 inches, and should cause the shackle to pivot 'forward' a bit - meaning the bottom of the shackle will move forward and be in front of the upper bolt (hanger mount). Is there a good angle for the shackle to make? Not sure if this would be the proper way to measure the angle, but I would consider a vertical shackle to be at 90* (kind of like mine is right now), and one that sticks out straight in-front of the hanger as 0*. Seems like 70* would be good number?

Now for the rear shackles - currently they are already shorter (about 4.5 inches bolt to bolt) than the front, although the jeep rides level. So I will probably to get shorter ones for the rear to reduce the lift and match the front (probably go back down to about 3 inches). Same question here - what kind of shackle angle/position would be good? Should rear shackles mirror the front and angle rearward (i.e. should the bottom bolt be more rearward than the top bolt), or should the rear shackle angle forward?

thanks

 

This shackle geometry description seems to be common...if nothing else it gives me the inclination to look at measuring the shackle angle with respect to the datum line shown as opposed to horizontal (parallel to flat ground). Obviously I cannot really control the shackle angle - it will be the result of the leaf spring length (which I am not changing) and shackle length, but interested to see how it will affect things.

I got kind of interested in this because the current geometry seemed kind of different - mostly that the current shackle angle is just under 90* but the shackle hangs vertically down from hanger. Based on the schematic, shortening that shackle will increase shackle angle, but given the specific front end geometry for this Jeep, the datum line actually tips down from the solid rear mount to the long front shackle (basically just take the schematic and rotate CW till the datum line goes down to the right). Thus shortening the shackle will make the datum line more horizontal, decrease the shackle angle a little more, and push the bottom of the shackle forward of the top bolt. Hopefully improving on road handling and unintentionally stiffening the ride under compression but providing more droop. I'll take those results for the fronts - next have to investigate the rear set-up.

 

Thanks Tarry - I'll look into the Rugged Ridge options as well. Been leaning towards some M.O.R.E. shackles and I am hopping dropping to a 4 inch shackle will bring the shackle angle back to a reasonable zone as you describe. Don't know if the springs are the original springs so no guarantee they are the correct length - shortening the shackle will move everything in the correction direction...2 inch shorter shackle is significant, just hope its enough.

 

got it! many thanks as I would not have thought of that - will measure it this afternoon.

 

Anyone have experience/opinion about either Daystar (KJ60001) or Warrior 191 Shackles? Both make a 1/2 inch lift shackle (4inch bolt to bolt) that would be a good downsize for my Jeep. Any likes, dislikes, concerns?

thanks