Shackle Reversal Question

DanStew · Jul 18, 2017

The original rover frame has a shackle reversal from the factory. The shackle mount, the bushing is in the frame. And with Jeep shackle reversals they too are in the frame.
BUT does the shackle mount have to be inset in the frame? Is there something bad if you do not?
I ask because the original frame on the Rover is 3x6 and the frame I am using is 2x5. I am trying to account for the 1 inch difference because in essence it will lower my suspension an inch. I want to retain that height and to do that I will have to mount my shackle under the frame, just like the rear spring.
Is there any issue to having the front leave spring, in a reverse shackle setup, with the shackle mount under the frame rather than through it?

ITLKSEZ · Jul 19, 2017

Can you just run a longer shackle to get your mount higher?
I'm one of the rare few around here who is a fan of shackle reversals. They offer such a more-natural motion of the front axle.
I run one on my 3b with stock Wrangler springs SOA, and I ran the mounts through the frame with a 5 1/2" long shackle (eye to eye). Aside from the increased strength and piece of mind knowing I'd never rip the mount off the frame, this also allowed me to use the frame as a sort of rub-rail to prevent side-to-side movement. I'll dig out a pic if you want.

tymbom · Jul 19, 2017

I'm a fan of shackle reversals as well... I've never had a rig with the shackles forward. My 1956 CJ5 had the factory shackle reversal, all my Chevy trucks have the shackle to the rear... I don't see the problem... Having the upper bushing inset in the frame would be stronger though... I think. A nice long shackle would give a smooth ride I imagine

ITLKSEZ · Jul 19, 2017

I know this isn't really answering your original question, but it's just food for thought. I should add... I built my 3b for racing, not for road comfort. If I had my shackles up front, my springs would be destroyed after one race from impacts against rocks and other vehicles.

If running flat springs like I am, standard (front) shackles actually offer a less jarring ride. Because the springs are flat, with the hard mount in the rear, the axle can travel nowhere but rearward in an arc around the hard mount. With a shackle reversal, that arc is from the front, so the axle wants to move forward on impact: jarring. (I have my bumpstops set for only about an inch of free uptravel, so in my case I don't notice it.)

If your springs have an arch, the opposite is true. Because of the arch in the spring, during uptravel the spring is still growing in eye-to-eye length, so a shackle reversal will be less jarring. It allows the bumps in the road to absorbed more naturally.

I found these illustrations online that explain it in pictures.

To answer your original question, mounting your shackle mount under your frame as opposed to through it will not be an issue. It will add a little stress to your frame, but your tube frame being substantially stronger than the factory frame won't even notice it IMO.