Reinforcing XJ control arms

The lower control arms on my off road Jeep have taken quite a beating. I have considered going with after market control arms, but for now with just a three inch lift, I am sticking with the stock control arms.

My first modification to get more droop was to modify the axle above the control arm mounting points. The mounting plate for the shock and spring hits the control arm at full droop limiting the flex. I simply hammered and ground away a lot of the offending material. It adds no strength to the axle and is just in the way.

The other part of the control arm that gives me trouble is where the front axle end bushing is pressed in place. The arm is just folded over here and when hit, it tends to crush and allows slop in the bushing.

When changing the bushing, you have to place a piece of metal in here to keep the arm form crushing while pressing the bushing in or out. To strengthen this area, I cut a length of pipe the size of the inside of the control arm. About 1 1/4 inch. I then cut this in two to make two C shaped pieces. I then hammered these pieces inside the control arm over the bushing. I then welded them in place.

These braces will prevent the control arm form crushing and hopefully prevent some of the bushing damage that occurs when I hit the control arms on rocks.

I also fabricated some guards over the axle mounting points that will further protect the front of the control arms.

After bending one of my control arms at Wooly’s Off Road park, I decided to strengthen them in the bending direction as well. I did this by cutting a piece of 3/4 in ch pipe and placing it inside the U part of the arm. I have seen people plate the bottom but this would keep the arm form twisting. The twist allows the suspension to flex more. To add strength and still allow twist, I drilled three holes int he top of the arm and plug welded the pipe to the arm just at the top.

The pipe should add strength to the bending vector but still allow the arm to twist as designed.

I look forward to seeing how these low buck modifications perform of the trails.

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