How to reduce power steering assist in an '05 LGT

[ebpda9]

More caster.

 

I am wondering why these cars don't have more from the factory.

 

Think of it like this.

 

no caster: a caster wheel that spins around in one spot.

little caster: caster wheels that are offset. (wheel axle is "forward" of the steering vertical axis.) pushing or pulling the wheel gets it back in line;

 

Lots of caster: a long rake chopper motorcycle. Wheel is way out in front, and the steering axis is at a shallow angle. The wheel axle is usually in front (or even above) of the steering axis

 

the angle of the steering axis from the ground is the rake angle. The distance between a theoretical vertical line through the wheel axle and the ground, and the point where the theoretical steering axis line intersects the ground, forward of the axle line, is called "trail".

 

The high amount of caster creates an effect that automatically uses the suspension to center the wheel. to turn the wheel either direction takes more effort, and actually tends to put force on the suspension. the natural state is straight ahead, and it tends to self-center.

 

A motorcycle with purely vertical forks would be nearly impossible to use, as the front wheel would be all over the place, all the time. Choppers on the other hand, are usually slow to turn, and once turning, tend to "fall into" the turn.

 

A sport motorcycle tends to balance those effects for short trail, and steep rake, to make steering as easy and quick as possible, at the edge of uncontrolled. That is why they put fluid dampers on the steering yokes... to tame down the steering oscillation while allowing such geometry.

 

Cars are slightly different, considering that there are two parallel front wheels, but the suspension principles are the same.

 

lack of caster is likely what makes the car so easy to turn, and also easy to wander, and get blown around. Grippier tires simultaneously help and hinder that. (more grip available for traction, but also more tendency to tramline and wander due to the road surface.)

 

With two parallel wheels also have a measurement for toe-in, which measures the distance between the forward side of the tire centerlines compared to the track dimension between the wheel centerlines at the hubs, which is fixed. toe out or toe in. adjusting half a degree or so in or out can have different effects on directional stability, but can also wear tires, and change the way the car enters turns (resisting turn in more, or falling into turns...)

 

Camber has a little less to do with turn-in, but can affect stability. more negative camber can make the car feel more stable in lateral motion.

 

Bottom line, before reducing power assistance to the steering, it would probably be better to fix the geometry problems.

 

Offset bushings for caster, camber adjustment, and perhaps some toe adjustment. (and keep in mind, that rear suspension settings can effect the way the back of the car follows the front, and make the car feel different, too.)

 

A good alignment shop should be able to set up a four wheel alignment that leans toward performance and stability. Sometimes settings from the factory can be different from side to side, within the wide range of acceptible specification, and could be on the comfort, easy steering, plush end of the adjustment range. Going the other way might help.

 

Offset caster bushings, and camber adjustment plates at the top of the struts, and a good alignment could shape things up well, while not underdriving the hydraulics, or degrading easy steering at parking lot speeds.

 

drove hondas with half the caster amount the legacy had and the steering weight is just right, also there were no straight line stability issues, even after on incident where the caster on the passanger frot went to -2 degrees, while the front was +2.5. The car would pull bad, but never had any straight line stabilty issues.