How To Replace Your Pitman Arm or Steering Arm

Idler Arms and Pitman Arms are part of your steering system that links your steering box to the center link, and then on to the hub assemblies. The Pitman Arm, also known as the "steering arm," is the main player while the idler arm supports the other side and allows the proper movement to take place when you turn the wheel. If your steering has gotten sloppy they may need replacement.

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Understanding Your Pitman Arm (and Idler Arm)

This is your Pitman or Steering Arm
Pitman arm replacement is not too tough a job if you're prepared. photo by Chuck

Signs of this are your steering wheel moving 2 inches or more from side to side without turning the wheels at all, front end shimmy that can't be attributed to out-of-balance wheels, or lurches to the left or right when you go over a bump. Sometimes only one is bad, but many people say that replacing both of them is easy, good insurance, and doesn't cost much more because the labor is essentially free (since you already have to take everything apart to replace one or the other.)

If you think it's time, read on and you'll be able to get them replaced in no time. And thanks to Chuck for the chance to show you how on his Hummer!

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Tools You'll Need

man looking under hood of car
Tuan Tran/Moment/Getty Images

Be sure you have all your tools for replacing the Pitman arm before you start. It's tough to go to the auto store with no steering!

What You'll Need:

  • 18mm - 1/2 drive wrench and socket
  • Pitman arm puller
  • 1-5/16 - 3/4 drive (big) socket and breaker bar to remove pitman nut
  • 5/16 - 1/2 drive socket and a long breaker bar/pipe
  • 11/16 and 5/8 - 1/2 drive socket and wrench
  • Torque wrench that goes to 180 ft lbs
  • Diag wire cutter
  • Flat head screwdriver
  • Needle nose pliers
  • Jack stands and a floor jack
  • Grease
  • 2 Cotter pins 1/8 x 1-1/2
  • New Pitman Arm

Got it together? We're ready to replace that Pitman.

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Remove the "Big Nut"

Remove the large nut that holds the Pitman arm in place.
Remove the large nut that holds the Pitman arm in place. photo by Chuck

We have to get it in the air, so jack the left side (most cases, see your repair manual if you're not sure) of the truck up under the A-arm and put a jack stand under the frame on the left side. Lower the truck down on the jack stand and remove the wheel.

You have to remove the big nut that holds the Pitman arm to the steering box. In this case, it was a 1-5/16 nut that was torqued to 180 ft lbs. I used a 3/4" drive socket and a big mother breaker bar. I was all ready for a battle, and it turned out that the nut was hardly tight at all. It came right off, which was not a good thing. Loose is never good when you're talking about steering.

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Pull the Pitman Arm from the Shaft

A Pitman arm puller in action.
Use a Pitman arm puller to remove the arm. photo by Chuck

Take your Pitman arm puller and remove the arm from the steering shaft. It will release from the shaft and drop down some, but the arm is still being held up by the centerlink.

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Disconnect the Pitman from the Centerlink

Centerlink nut being removed.
Remove the cotter pin, then remove the nut holding the centerlink in place. photo by Chuck

Next, remove the cotter pin and the large nut that holds the Pitman to the center link. Use a pickle fork or a puller to separate the Pitman from the centerlink. You should be able to remove the Pitman by pulling down on the centerlink and slipping it out.

If you're doing both the idler arm and the Pitman today, this is where you will appreciate the fact that you have not installed the idler arm yet. If you can't get the Pitman arm out, drop the idler arm down by removing the 2 bolts that attach it to the frame. Whew!

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Reinstall the Pitman Arm

Grease added to steering box area.
Use the grease liberally to protect all the steering components. photo by Chuck

Put some antisieze grease on the steering box's tapered bolt. Pack grease up into the steering box around the top of the tapered bolt. This will help keep out dirt and moisture. Prepare a new cotter pin by cutting down the length of one side to match the one you removed.

Take a rag and wipe the junk away from the steering shaft and the centerlink hole. Take a good glob of grease and pack it up all around where the steering shaft sticks out of the steering box. This will help seal the steering box from the elements.

Look at the inside splines on the Pitman arm. You will notice that there are 4 flat spots that match up with the splines on the steering box. Install the Pitman on the steering shaft making sure to line up the splines and at the same time insert the tapered bolt in the centerlink. Put the split lock washer and hand start the big nut on the steering shaft and tighten it to your vehicle's specs.

Install the large nut on the Pitman bolt and tighten it to spec, making sure that while you are turning the nut, you line up the cotter pin hole. Always tighten to align the holes, never go backward! Install the new cotter pin and grease the Pitman.

Now hit the road and keep on the straight and narrow!