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Shackle Reversal on a CJ2A


How to:

(Remember clicking on the images goes to a larger version. Back button returns)

The first thing to do was remove the existing front springs. Next, remove the radical front suspension mounting. This was accomplished with a cutting torch. Surprisingly, it came off without much trouble or damage to the frame. Then, the rear suspension mount was torched off. Under there were the remnants of the original spring hangers, complete with the original rivets. The rivets will help position the shackle pivot points. Both the front and rear mounting locations were ground to remove the remnants of the previous mounts.

Front suspension removed. If you look closely you will see ropes suspend the axle. Yes the drive shaft either comes off or comes apart.

Notice the line between the rivets on the bottom of the frame that continues up the side. This was used to provide horizontal position for the spring pivot hole. The vertical position was determined to be 1"

Notice the small 1/4" pilot hole. This was laid out and drilled from the inside of the frame to assure the hole goes through the frame squarely.

Now that old suspension supports are off, the area is fairly clean, I painted the frame so I could mark the locations for the shackle pivot holes. Looking closely at the center picture above, click on it for a larger view, you will notice a line scribed between the original hanger rivet holes and continuing vertically up the outside of the frame. I also scribed a vertical line on the inside of the frame. I determined the hole could be no closer to the frame bottom than 1" and a check with the folks at Willys Tech confirmed that 1" above the bottom of the frame was correct. Then I drilled a 1/4" pilot hole in the outside frame rail and again from the inside through the inside frame rail. This assured the final hole would go squarely through the frame. Of course I repeated this for both sides of the vehicle.

Hole saw cutting hole in the outside of the frame.

Hole saw cutting hole in the inside of the frame.

The holes were slightly under the bushing O.D. grinding to size was required.

The hole was ground to a light tap fit. It protrudes 1/8" inside and outside for welding.

The OD of the bushing tubes is 1/32". I used a 1" hole saw to make the holes and an air grinder to enlarge them so the bushing tubes just fit. They will be welded later. But first I will explain where these bushing tubes came from and why I needed them.

The urethane bushings came with the SuperLift kit I bought. They replace the steel covered rubber bushings that are in the pivot end of the springs and the screw in bushings of the U-type shackles we are all familiar with. They are 7/8" O.D. and have a 1/2" I.D. Also in the kit were steel sleeves that go inside the urethane bushings. These provide a smooth surface for the urethane bushings to rub against. The steel sleeves are just a little longer than the urethane bushings and thus keep the bushing from being crushed when tightening the bolt on installation. The bushing tubes will provide a surface for the urethane to bear against in the frame.

These are the Urethane Bushings and steel sleeves. As the text above states the steel sleeves go inside the urethane bushings and are just a little longer to prevent crushing the Urethane Bushing.

This an original shackle. Notice the left hand threads on the bottom. This allows the larger parts, which are in the spring and hanger to rotate without twisting the shackle as it moves through its travel.

I found that 3/4" pipe was very close to the 7/8" I.D. required for the bushings. I bought a length of pipe and cut it to 1/4" longer than the width of the frame. This gave 1/8" on each side for welding. Remember the holes they go into are a good fit so the frame holds the weight. The weld just keeps then from sliding out.

I made the bushings out of 3/4" pipe. Here the threads are being cut off the end of the pipe. Next the bushings will be cut to length.

Here are the bushings cut to length. Frame is just wider than 1 3/4". Therefore the bushings are made just longer than 2". This provides 1/8" welding lip.

I mentioned the I.D. of the pipe was very close to the 7/8" required for the urethane bushings. Actually the I.D. was slightly smaller. This is good as it provided some metal to drill out and yield a hole that fit very well. When you drill a very small amount of metal out of a hole this size there is a tendency of the drill to grab and pull through part. A reamer would have been a better choice. However a 7/8" reamer was not available and a drill was. The grabbing problem was resolved by 'making' a reamer-drill. Grinding a small flat on the cutting face of the drill does this. The pictures below explain this better than words can.

This 7/8" drill would grab when drilling through the bushings.

This is the modification I made to the drill. The flat prevents the drill from grabbing.

Here is the bushing being drilled (reamed) on a drill press.

With the bushing tubes drilled to size and fit to the frame, all that is left is to weld them in, grind them smooth and paint.

Ah, a little 'hot glue' supplied from the MIG welder. The inside of the frame is also welded.

The weld is ground smooth with the frame both inside and outside. The imperfections were filled with body putty.

Now the bushings are in the frame, I can start installing the front spring hangers. I need to place them the right distance forward from the bushings in the frame and the right distance apart. Additionally they need to be square with the world and as they are going to be spaced 4" from the frame they will need some support for strength.

The 4" spacing was handled by welding 2 pieces of 1/8" wall 2" square tubing together. An angle is cut on one end after welding and will be covered with a piece of 1/8" steel. This will aid in deflecting rocks and such. After the spacers are done, the whole assembly is assembled in place with clamps. The straight-line distance between the spring eyes determined the distance from the frame bushings when the spring is in its natural curved state. I wanted to have the distance as close to the same on both sides as possible. I used 2x2s with bolts through them to set the distance and drilled the holes through both 2x2s at the same time to make them exactly the same distance apart. The distance between the hangers was controled by 7/16" threaded rod through 1/2" electrical conduit.

Merely welding in a piece of angle iron all the way across the front could provide the strength. This would have negatively affected the approach angle. I decided to use some 1 1/4" O.D. tubing and angle it up in the middle to provide as much clearance as I could get. The round shape and open center should give a reasonable approach angle.

After the hangers were clamped in position, the 1 1/4" round (1/8" wall) was cut to fit, clamped in position and tack welded to the spacers and together. Sorry no pictures of this part, must have spent too much time trying to make it right and forgot to take pictures. Notice the spacers have the front boxed in. This provides additional strength, keeps dirt out and is designed to deflect the Jeep up if (when) I hit something. Here are some pictures after painting.

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Copyright Richard N. Meagley Sr.
Last revised: May 25, 2007.