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Replacing the Idler, Pitman Arm

Idler Arm

The Idler Arms and Pitman Arms in your steering system connect the center link to the steering box and hub assemblies. Idler and Pitman Arms are two parts of the same whole, with the Idler supporting one side and the Pitman (aka "steering arm")the other. These two work together to create strength and tight connections in steering while retaining open movement when you turn the wheel.

While not necessarily the problem on this person's car, it's a possibility (we never did find out), one major symptom of malfunctioning Idler and Pitman arms is "floating" when on the road - not having full straight-line control). Replacing the Idler and Pitman arms is best done as sets and most mechanics will recommend doing both sides as when one goes out, the other is likely to be seeing wear-and-tear too.

This job requires some specialized tools, including a Pitman arm puller, a torque wrench (to 180#), a safe way to raise the vehicle's front end, replacement cotter pins (size will depend on vehicle, usually 1/8x1-1/2 inch), and the replacement idler and pitman arms. Other tools are relatively standard shop tools such as sockets, wrenches, screwdrivers, wire cutters, etc.

This job can be done one side at a time or both sides at once, depending on your vehicle lifting capability. Some details will change according to the vehicle you're working on, but for the most part, removal and replacement of the idler and pitman arms is the same on most modern cars. Begin by removing the wheel from the side you're working on.

On top of the idler is a castle nut which has a cotter pin going through the exposed bolt coming out of the top of it. Remove the cotter pin. Using a breaker bar or other shop means, remove that castle nut. At the other end of the idler arm are two (sometimes three) bolts that hold it to the frame. Remove those as well.

Now comes the tricky part. Separating the idler from the center link is usually not all that easy. Beating on the top of the idler bolt can work, but may cause damage you want to avoid. This is why a Pitman puller is recommended. It should be sized to fit your arm, or thereabouts, to pull the idler. Once the idler is off, you should have clear access to the Pitman as the center link drops. Pull the Pitman off as well.

Install the new Pitman to replace the old, which can usually be done by hand with just a slight shove.

Now take the old cotter pin you removed, straighten it out and lay it next to its new replacement and clip the new one to match it for length.

Place the new idler arm in its position, starting with the center link bolt. You may have replacement bushings to add if they aren't already built-on. Insert new bolts through the frame to hold the new idler on and tighten those to torque specifications for your vehicle. Then add the castle nut (hopefully a new one) to the top and tighten that to spec as well. Insert the new cotter pin, aligning it with the bolt holes and nut, and bend the ends flat. Make sure you TIGHTEN to align holes, never loosen.

Add some grease and you're finished. Both sides of the vehicle are roughly the same.