subject: How To Maintain The Idler Arm1 [print this page] Just like your vehicle's braking system, the steering system is one of the most important vehicle safety and control systems, and it should always be in top shape. On Toyota 4WD vehicles with recirculating ball steering (pre-Tacoma and pre-'96 4Runner), an idler arm works in conjunction with the pitman arm to locate and control the steering links. The idler is infamous for worn bushings and for breaking on the trail: it is the worn bushings which this article will address. Worn idler arm bushings - exacerbated by offroad abuse - contribute to lack of steering response and diminished control, which is not safe on road or trail.
There are at least two ways to determine if your idler arm bushings are worn. The first, most obvious sign would be steering "feel": loose or wandering steering as the idler shaft moves laterally in the worn bushings. The second simple method of checking idler bushings is to have a companion turn the steering wheel while the vehicle is stopped, and observe the movement of the arm: if it pivots down or the arm moves sideways before wheel turn occurs, the bushings are worn.
Fortunately, bushing and seal replacements cost less than $15 and takes maybe an hour of time to complete.
Tools and parts needed to replace the idler arm bushings and grease seal include:
Two replacement bushings, Toyota Part Number 90386-19005 for newer trucks, and 90385-18068 for older trucks. Please check with the dealer to be sure which bushings are appropriate for your vehicle!
Replacement grease seal, Toyota Part Number 90304-31012
17mm socket and 17mm box wrench
19mm socket for idler shaft nut
Flat blade screwdriver
Pliers
Pickle fork and hammer, or small tie rod puller
Torque wrench
MP grease
Steel wool
This entire procedure can easily be done without raising the vehicle. On an IFS vehicle, begin by removing the skidplate. Pull the cotter pin from the idler arm stud through the steering link, and remove the 17mm castle nut. The arm must then be removed from the link: for this, I used a pickle fork. I greased the tines of the fork and drove it towards the stud and popped the stud free without damaging the grease seal.
The idler is secured to the frame rail with three 17mm hex-head bolts. Put the box wrench on the bolt head, and use the socket to remove the nut. They are likely to be very tight, so a cheater bar or penetrant may be necessary. Once all three bolts are removed, the entire idler assembly can be removed from the vehicle. Note: the shortest of the three bolts is for the upper mount.
