What do these things do? They move the Mustang steering rack rearward in the chassis and increase the effect of Ackerman steering geometry.
Solid bushings also eliminate the steering rack movement allowed by rubber and urethane bushings.
What is Ackerman steering geometry? It causes the inside and outside wheels to rotate around the same point in a turn. The inside wheel has to turn a bit sharper than the outside wheel to do that.
Most production cars lack full Ackerman steering. If you add some, it will reduce rolling resistance and tire scrub in turns.
- Disconnect the battery ground wire.
- Raise and support the vehicle with jack stands. The more you raise the car, the easier this job will be.
- Go behind the K-member, and remove the bolt (13mm) that secures the flexible coupling between the steering column and the input shaft of the steering rack.
Do not rotate the steering wheel while this coupling is disconnected, or you will damage the air bag sliding contact.
- Remove the two nuts (19mm or 3/4") and washers holding the steering rack to the K-member. You will probably need to
hold the rear of these long mounting bolts to keep them from turning (15mm socket & long extension).
- Pry out the front rubber bushings, pull the rack forward from the K-member about 4 inches, and use a scribe to mark each metal sleeve where it enters the K-member.
- Remove the rear rubber bushings from the metal sleeves and the back side of the steering rack.
- Pull the metal sleeves out of the K-member (vise grips). They are pressed in tight, with a taper fit.
- Cut off the metal sleeves 1/32" to 1/16" in front of your scribed marks so that they will protrude slightly out of the K-member when they are reinstalled.
The sleeves are needed to correctly locate the bolts in the front holes of the K-member. (see illustration below)
- Reinstall the shortened sleeves into the K-member. Install the aluminum bushings into the steering rack from the front side.
Note in the illustration above that the aluminum rack bushings do not touch the K-member. This ensures that the rack is bolted tight against the K-member, and prevents the
sleeve from touching the aluminum rack bushing.
- Move the steering rack back into position, sliding the aluminum rack bushing onto the mounting bolts.
- Reinstall the flexible coupling into the input shaft of the steering rack and secure it with the original retaining bolt (13mm).
- Reinstall the original washers and nuts (19mm or 3/4") onto the steering rack mounting bolts and torque the rack mounting bolts to 30-40 ft/lb.
- Lower the car and reconnect the battery ground wire.
As you can see in this picture, the elimination of the rear rubber bushings allows the steering rack back to be bolted flush against the K-member.
It is moved back about 1/4" from its original position. This causes a change in the toe setting. Before the car is driven any distance, the toe setting should be adjusted at an alignment shop.
The cost of these rack bushings was $39.00 plus $4.72 shipping & handling.
UPDATE - 06/30/06: Maximum Motorsports found that on some cars the K-member has an irregular surface that causes these rack bushings to be mounted at an angle which distorts the steering rack and causes grinding.
They have solved that by adding washers (shown below) that cause the bushings to align correctly.
I haven't had any problem with my steering since installing Al rack bushings several years ago, but if I was doing the job again,
I'd make sure I installed the new versions.