Idler Arms

Partner of the Pitman arm, which connects the steering box to the steering gear, the job of the

idler arm

is to hold the right side of the steering linkage. Between them, the centre link is supported in the proper position so that the left and right wheels work in unison.
As Idler arms have an integral pivot function it usually makes them more susceptible to wear than

Pitman arms

. For quality idler arms check Eurocarparts.com, where you should quickly and easily be able to track down idler arms for any car.
 

Pitman Arm

The Pitman arm is an essential component in a car's steering, connecting the steering box (or steering gear) to the centre link. Essentially, turning the steering wheel makes the steering gear turn the Pitman arm, which in turn moves the steering linkage and turns the wheels.
Both the Pitman arm and the

idler arm

work together linking the steering gear with the centre link to ensure that the wheels move in harmony, creating a parallel steering linkage.
If you need a replacement Pitman arm, Browse Eurocarparts.com to find

Pitman arms

for every make and model, which are readily available.