Boxing your rear LCA (trailing arms)

This is the stock rear control arm.  It is also known as a trailing arm.  Two of these and a torque arm is really all that bolts the rear end to the body of the car, so you can see the importance of these peices.  From the factory, these are stamped steel, wich are very weak.  Aftermarket ones are available that are much stronger, but if your on  budget, you may choose to do it yourself (aftermarket ones are much lighter however).


Using flat bar stock that was about the same width as the LCA, I marked where the contours of the LCA changed, and then grooved the bar for easier bending.  You can use narrower bar to fit inside the LCA, but I got these for free, so thats what I used.


After undercutting the first two grooves, the first two bends were made to fit the contours of the LCA.  The bends were made in a vice and test fitted.  It was trial and error, but patience paid off.


A total of four undercuts and four bends were needed to match the contours exactly.  Then the bar was cut to lenght.


Once the bar is bent and cut to length, it can then be welded to the LCA.  After welding, the welds were ground smooth, and some of the excess bar was also ground off.  After final assembly, it was then painted.  This is also a prime time to install the Poly Bushings, but I didn't have them when I did this.

Here is the final product.  This really stiffens up the LCA's.  If you can't afford aftermarket ones, and can deal with the little extra weight, than this is the way to go.  Gains were minimal, and I would have benefited more with Poly Bushings,  but evey little bit counts.

 

 

[TECH INDEX]   [HOME]