Spring Shackles

My 67 CJ5 has aftermarket spring shackles front and back that look to be 2" over stock. Probably in the past it had oversize tires on it. I plan on staying with stock tires so I don't need the lift and I seem to remember somewhere reading about shackles not being the best way to lift a vehicle anyway. Is that correct? Whats the collective here think about that and also does the lift in any way effect the camber of the front wheels? Keep the shackles I got or go back to stock?

 

Your thinking is correct..

The standard 2-3/4" length shackles are ample length to allow for flattening of the standard leaf curvature.

I certainly suggest you go back to standard shackles unless you have other specific needs.

 

The shackles would affect the castor angle which can be corrected with shims between the springs and axles. The longer shackles could help if you were using a lift spring with more arch which could benefit from the increased shackle movement. To me the problem with longer shackles is the increased leverage they can put on the shackle mounts side to side, potentially cracking the frame.

 

O.E.M. style shackles are available.I believe Kaiser/Willys and probably others have them. I like the original look on a stock jeep.

 

Thanks for those replies. Looks like I'll go back to stock, another thing to put on this winters to do list.

 

I'd like to suggest that you also plan to replace )or at least keep an eye on) all driveline u-joints.
Lifting will change driveshaft angles that can introduce vibrations that as mentioned can be corrected with shims installed between the leaf spring and it's perch.
If you remove shims probably a good idea to replace the u-bolts. Depending on the resulting driveline angles the pin bearings in the u joint caps can make a wear pattern that may not like the new (stock) driveline angle. Check this site for some good driveline tech: Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist

 

Ditto on Tom Woods. Excellent products.

 

Your 2" longer than stock shackles yield 1" of lift. Pretty minimal but yes, all of the issues mentioned above are correct. I used 1" longer than stock shackles to yield 1/2" of lift. Im okay with that. 2" longer is the max I'd ever consider for a shackle lift.

 

Your factory shackles would be like these Shackle Kit Silent Block Type 1957 Up

 

The reason long shackles are frowned on is the additional wear that's incurred on the bushings. As the bushings (and mounting points/hardware) wear because of increased leverage more and more slop in the components create a loose and wandering ride on road that in time can become unsafe. i.e. a longer lever arm ncurrs more force = more wear over time. On a vehicle it's fairly easy to notice and repair. Shackles are generally viewed as a cheap way to get lift for clearance or larger tires rather than the more expensive re-springing. Some also install blocks between springs and axles that is viewed by others as potentially weakening springs by introducing (a lever arm) point loads where the block contacts the spring.
Last thought check your shock heights if you go down on shackle height as p.o. may have installed extended shocks.

 

Blocks between the spring and axle will only provide lift on a vehicle with the leaf spring on top of the axle housing. With the springs under the axle (like our Jeeps) a block between spring and axle will lower the vehicle.
Otherwise, good info.

 

I built my 3B shackles to also give 1/2" lift and those have stood the test of time well-about 42 years. I think part of that is due to shackles made of 3/8" plate with a tee section welded between them. There is no side to side give as you get with the stock 2 piece shackles, especially after the wear a bit. The bolts remain parallel at all times which helps diminish the loading on the bushings. IMO. also part of the problem is the 7/8's ID of the spring eyes and hangers. Doesn't leave much for bushing wall thickness.

And while you can shim to correct the front axle caster, those shims exacerbate what is usually a bad pinion angle to start with. No free lunch there short of cutting off and re-welding the spring perches.