When Springs Break (Part 1) covered the basics of spring flex and potential problem that can arise. Springs are a critical part of your suspension to provide for tire contact with the ground and keep the axle of your 4x4 centered while allowing movement. So, what are solutions to reducing the chance of spring failure? Certainly, moving to a coil spring suspension is one option to eliminate the flex issue with leaf springs. Another option is to install to a shackle reversal. That is a simpler and more cost effective option.
As noted in Part 1, leaf springs have a fixed point and a movable point. For the front leaf springs, the fixed point is about mid-center of the vehicle. When the front wheel encounters an obstacle, it is pushed back against the fixed point. The force can cause undue stress on the spring and a potential for breaking near the rearward spring hanger: the fixed point.
With the shackle-reversal, the fixed point is moved forward. This will provide for less stress near the rear spring hanger as the movable point allows the spring to move and flex. Overall, there is a reduced chance of bending or breaking. Okay, time for a shackle-reversal and new springs.
A call to Rubicon Express revealed a three-plus week lead time for replacement springs. Next alternative was to have a new main leaf built which could be done within 48 hours. Luckily, National Springs is local (Santee, CA) and has the ability to do quick turn-around. Once on the hoist, a close examination showed that one spring was crack and the other front spring had an un-natural bow -- it was bent. Now, it is two, not one main leaf spring that is needed. The turn around time through National Springs was still the same for two springs.
Interestingly, the Rubicon Express springs are .260 thickness material. The new springs from National Springs are .291 thickness. The thinner material provides more flexibility; however, strength is sacrificed.
The shackle-reversal kit was provided by T & J Performance of Orange, CA. The kit consists of heavy-gauge steel boxes that are welded to the frame and serve as the fixed point for the spring hangers.New shackles are also provided. In all, the kit is structured to accommodate no lift to up to 2.5 inch lift from springs. The kit comes with holes for no lift springs. Accommodating springs with lift is a matter of drilling new bolt holes to mount the springs. As an added feature, the bolts do have grease fittings.
The Slick Rock hangers were soon removed and the final custom fitting was done to shape the new front hanger to the frame and welded into place. The shackle-reversal and new springs were installed in time for Tierra del Sol Desert Safari.
The new springs were thicker and I have no complaints about flexibility.
But, the story does not end here. Part 3 will go into more detail about broken springs and emergency repair. Yes, a rear leaf spring did break.
Check the 4x4Wire Jeep Tech Galleries for more installation pictures.
Work was done by:
Roger Daniels Alignment & Brake
8517 Ablette Road, Shop F
Santee, CA 92071
BAR # ARD214109