Lubricant for steering? (Potential solutions for Mirage's lack of self-centering)

[MetroMPG]

^ Have you tried it by any chance?

[ahintofpepperjack]

^ Have you tried it by any chance?

I have not, but I doubt it would correct the non-centering problem. I think these cars are just too light, with tiny tires, not enough force on the wheels to keep them centered. Wider tires would help I'm sure.

[MetroMPG]

I don't think that's necessarily it. My little Firefly/Metro has better steering, and it's lighter and has even skinnier tires than the Mirage.

I asked Mitsu Canada about this specifically (self centering), and was told the steering behaves the way it does because it was designed to be easy to use. A tech person replied:

One of the pillars of design was ease of driving during low speed maneuvers and parking. Very tight turning radius was the goal to achieve this.

He also sent an attachment that I couldn't open. (I asked for a re-send but never heard back. Maybe it's time to ask again.)

I'm no suspension expert, but I do know that a design with very little caster will enable light steering effort, but will have weak centering. I don't know how caster affects turning radius.

Also on the issue of turning radius, the 2015 Micra available in Canada has the same super tight turning radius as the Mirage. But the little Nissan has vastly better steering feel & self centering. That's my subjective opinion, but I'd be willing to bet that if Mirage owners could have the Micra's steering, the majority of people in this thread would choose it.

[ThreePot]

The electric power steering on the Mirage is just an electric motor bolted onto the steering column. Just reach under and unplug it for manual steering.

.
Yes, you would have manual steering.
But...The EPS unit's not that simple.
Now your back driving the servos in the EPS unit when you turn the wheel.
It won't feel like the rack and pinion would feel by itself.
You still have a pile of drag from the disabled EPS.
IMHO

[MetroMPG]

Supports the steering geometry explanation...

Caster affects straightline stability and steering wheel return [self-centering]. High positive caster makes the front wheels want to go straight ahead.

A normal amount of positive caster provides stability and makes the steering wheel straighten out after turning.

On the other hand, positive caster increases the effort needed to turn the wheel. Power steering allows the use of more positive caster than would be acceptable with manual steering.

Source: http://www.motor.com/article.asp?article_ID=552

[MiMi]

I'm interested to hear if other Mirage owners have the same characteristics as I do. There is a dead area from having the steering wheel about one-eighth turn to the left and to the right. In this area, the wheel does not self-centre. Beyond that area (as when doing a 90 degree turn) there is a strong self-centering force. The result is that no problem is noticed during city driving, but there is constant need for correction during highway driving. I do not notice any "stickiness" in the movement of the wheel that one poster mentioned on this or another thread.

[MetroMPG]

Mimi, yes the steering behaviour you describe has been noted in multiple media reviews of the car and by many owners here.

I think the "stickiness" may just be another way of describing weak self-centering / steering wheel return. EG. the wheel "sticks" when slightly turned, rather than returning to center.

[MiMi]

Thanks for the reply, Metro. I know nothing about steering mechanisms, but this is how I see it. Since there is quite strong self-centering after a 90° turn, there is positive camber. The drag of the steering mechanism must be greater than the centering force when the steering wheel is nearly straight. So maybe the OP of this thread is correct in that the steering mechanism just needs some lubrication.

[IchabodCrane]

Yes. There is positive camber
Yes. The wheels do return towards center from a 90 deg turn (although only to the vague L1/8 turn to R1/8 turn center)
No. There is nothing to lubricate.
No. The "mechanics" are not sticking
The issue lies in the electric steering assist. The motor on the shaft relies on "sensing" the need for assist, as when we turn the wheel. Unfortunately the sensors and software that uses them are tuned very loosely to center, resulting in a vague, sloppy center "zone" where steering response is poor with minimal feedback.
Simply a less expensive design in keeping with the Mirage's frugal concept which works fine for slower, less refined roads found in the original intended markets.
I believe Mitsu should have tweaked the steering system to tighten things up for the expanded market. An oversight on their part that they will hopefully remedy.

[ThreePot]

IMHO,
If you could chuck the EPS unit and replace it with a shaft, the car would steer like it should.
As long as that EPS unit is there, you are stuck with the piss poor centering, lack of feedback, lack of road feel,etc.
You can lube, adjust, tweak, change wheel sizes, complain to the dealer or corporate all you want. It is what it is.
I have a boneyard quoting me on an EPS unit out of a wreck. Depending on how the internals are set up, I may be able to gut it and prove / dis-prove my claim.