We're on our third Camry, best cars we have ever had. Several weeks ago the rack and pinion (r&p original) on 2002 Camry was leaking so MECHANIC indicated we should probably get it replaced. MECHANIC put in rebuilt rack and pinion (r&p-1). After installation, I noticed that when wheel turned far left or far right, it seemed to get too easy to turn steering wheel at far left and far right and really did not feel proper. This feel was more prevalent at far right turn. When steering right or left (for instance to change lanes or around curves), steering was not as firm as we had remembered, though I would not really consider it loose. Steering seemed more sensitive to bumps. Took it to another shop, and they indicated problem was that rack and pinion was not centered, causing steering to feel less firm on far right turns (I wasn't so sure about this answer). I took it back to MECHANIC, who agreed that steering did not feel proper, and he said he also detected maybe some general looseness in the steering. But he said that rack and pinion only mounts one way, and that wheels were correctly aligned, so that there was no way rack and pinion could be off center. I asked if it could be the wrong rack and pinion for the car , and MECHANIC said he was sure it was the right one. MECHANIC concluded that problem was that r&p-1 was a bad rack and pinion and so MECHANIC replaced the rack and pinion again with another rebuilt rack and pinion (r&p-2).

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This new rebuilt rack and pinion (r&p-2) feels better than the first rebuilt
rack and pinion (r&p-1), but I am still not sure it is proper or the same as r&p-original. Here is what I observe.

When front tires pointed straight ahead, steering wheel is centered (seems OK).

To steer to extreme left, I can turn steering wheel ~ 1-2/3 turns to left from center (seems OK).

To steer to extreme right, I can turn steering wheel ~ 1-2/3 to right from center (seems OK).

On road, when steering right or left (like to change lanes or around curves) steering feels more firm with r&p-2 than r&p-1, but not as firm as I recall with r&p-original, or with my 1998 camry (so seems maybe questionable). When I make a left or right turn (i.e. picking up speed after making turn), steering wheel returns to center on its own (seems OK). When making right U-turn, steering wheel returns to center on its own (seems OK). WHen making left U-turn, I have to assist the wheel some initially to get it to come back to center (maybe not OK).

In the parking lot:
When turning right at slow speed to park, steering wheel returns to center on its own (seems OK). When turning left at slow speed to park, I have to assist wheel some to get it to come back to center (maybe not OK). If turn all the way right and drive car slowly in right tight circle, if release steering wheel while driving in tight circle, it returns to center on its own. If turn all the way left and drive car slowly in a left tight circle, if release steering wheel while driving in tight circle, it stays to left on its own while I drive (maybe not OK). If turn steering wheel 1-1/4" turns to left and drive car slowly in tight circle, if release wheel, it turns further left on its own while I am driving slowly in the tight circle (maybe not OK).

Some questions?
1) Could there be a problem with this rack and pinion (R&P-2) or the way it was installed? If so, how to fix?
2) Why wouldn't wheel return to center on its own after turning left to park.
3) Why does wheel turn further left when I release the wheel while driving in left tight circle (versus going back to center), particularly since it does not do this when driving in a right circle?
4) Could there be some kind of problem with centering of the rack and pinion?
5) Could it be that hydraulics in the rack and pinion (r&p-2) are not working properly to return wheels to center after left a U - turn or when driving in left tight circle?
6) It almost seems like wheels turn to far to left, but I am not sure this is possible (what physically controls how far wheels can turn to right or left ... does pinion reach a stop on the rack? is there a stop on the steering wheel?). Is it possible wheels could be turning too far to left?

A better knowledge of camry hydraulic rack and pinion coupled with more experience with the feel of camry steering would be best.

Would be grateful for any response/insight on this.

Regards, Barry

 

Surprised the mechanic so quickly replaced the rack. Is it possible there is a problem with these rebuilt units thus no debate took place about replacing it. Replacement is not an easy job and cost $$.

Did the mechanic check the wheel alignment on an alignment machine?

The rack only mounts one way.

When driving the car straight ahead is the steering wheel centered (not turned one way or the other)?

Does the car continue to move straight ahead as opposed to drifting one way or the other?

If the car hits a bump does the car want to change directly ever so slightly.

After rack replacement the wheel alignment starts by having the steering wheel centered, then the tie rods are adjusted to obtain the proper toe in.

It is possible the lower U-joint on the steering column is binding causing poor return to neutral.

Because the suspension needed to be taken apart the strut position can change slightly upon putting things back together causing slightly different steering characteristics or drifting.

The rack has hard stops at each end of travel, only so much hydraulic stroke distance.

With the wheel at the far left turning position compare tire angle on each side, they should be the same. Do the same for a far right turn.

 

Thank you for response, Toyomoho.

I presume MECHANIC aligned car on alignment machine because his shop does tires and alignments and he charged for an alignment after putting in new rack and pinion, and he indicated that alignment was required after putting in rack and pinion. But I cannot be sure. Car drives/holds straight on freeway, like it is aligned.

When driving car straight ahead, steering wheel is centered (it might be a degree or two off, but as close as I can tell it is quite centered) .

When driving the car straight ahead, you can release the steering wheel and car holds straight, versus drifting to one side.

If the car hits minor bumps while driving straight ahead, the steering wheel turns slightly side to side, but comes back to center after the bumps (i.e., car remains rather straight).

When turning steering wheel hard left, the two tires look to have about the same angle the best that I can tell, but it is sort of hard to tell by eyeballing it. Same is true with turning wheels to hard right.

I have driven car a little more, and basically with a slow (like parking speed), sharp turn to left, wheel turns further left on their own if hands are off the wheel, and does not come back to center on its own. This effect seems to be more pronounced the sharper the turn (i.e, farther left) and the lower the speed. A few times, depending upon turn, speed, and slope, I observed this time same was sometimes true for the right but to a much lesser extent.

If tires are aligned, is it possible for wheels to turn further left than right, or too far left?

After a turn, what restores wheels to center position? Is it hydraulics, springs, effect of road on wheels, some other force? (In this case of my car, on slow far left turn, if release the wheel, wheels turn further left on their own. )

I know hydraulics assist in turning wheel to right or left to make it easier to steer. But do hydraulics also in some way assist in returning wheel to center? Could this be a case that hydrualics are not working well enough in restoring the wheels from a turn, particularly from a left turn?

Barry

 

Front what you describe in the first half of your post the steering system is act normally.

Each front tire has its own toe-in adjustment. Given the rear suspension also has adjustments for toe-in it may be possible the front is OK but when combined with the back no longer OK.

Having both tires off to one side or the other the same amount but the steering wheel centered is very possible via the adjustment mechanism however the alignment process if done correctly should not result in this happening. And if so when the steering wheel was centered the car would be turning.

Center the steering wheel, look at the front tires. They should both be pointed ahead.

Caster setting aids the wheels to center after making a turn.

The tire acts like a castor attached to a shopping cart. Forward motion of the cart tends to straighten the casters direction out.

After a certain turn angle (say max steering wheel rotation position) caster may cause the wheels to no longer self center.

Self center should be a result of the cars suspension geometry. The steering should require force (aided by the power steering) to overcome to tendency of the wheels to self center due to the wheel alignment.

The hydraulic system is basically a two-way ram. Fluid pressure pushes the ram one way or the other. Pressure is applied to one or the other side of the ram via a valve system reacting to the steering wheel being rotated.

Suppose if the self centering tendency of the geometry forces the tires to center causing the steering column to rotate the PS system would activate. The valve system only knows the steering shaft is being rotated, not how.

The PS system does not know where the center is, where to self center so the car is going straight.

Would assume if the car alignment were so off the steering may center with the car going off the road in a turn.

The power steering is power assist. If the power steering pump broke the car would steer the same, the steering wheel would be much to turn. Not a problem once the car is moving but making parallel parking much harder.

Issues that can cause problems with the steering wheel self centering are:

Tire pressure.
Binding of the steering column or rack inside the housing.
Wheel alignment.

On most front wheel drive cars caster is not adjustable without installation of some kind of after market kit, same for camber. The only adjustment is toe in.


If you have the money find a reputable fully equipped alignment shop that can check caster, camber and toe-in for all 4 wheels. Discuss your concerns with someone that understands all aspects of alignment. I understand some but far from an expert.

It may be possible some other alignment aspect is off, Your current shop may have limited itself to checking toe-as this is the only thing they can adjust without installing an aftermarket adjustment kit.

While the shop is checking the alignment have them remove the tires to look at the suspension for loose or worn parts.

 

Thank you so much, Toyomoho.

Sounds like alignment is highly suspect. So I plan to have this checked further now.

I think I understand from your response that : In general, for a car in good alignment and good working condition, when coming out of turn, tires and steering wheel tend to return to center, when steering wheel is released, due to car's suspension geometry, which likely also activates the power steering; thus power steering is making it easier for the wheels to return to center once tires begin to steer toward center on their own (even if there are no hands on the steering wheel).

I percieve that it may follow as well that ?? : If some aspect of misalignment causes tires to steer further left on their own (i.e., upon releasing steering wheel) during a sharp left turn, that potentially, power steering pressures may kick in at same time (due to steering wheel rotating on its own) and make it yet easier for the tires to continue steering to the left on their own. (The valve system only knows the steering shaft is being rotated, not how.) I.E., any minor tendency for tires to pull further left in a left turn (with hands off steering wheel) gets assisted by the power steering, making it even easier for tires to steer further left on their own ! ?

Barry

 

Not sure about the PS making things easier to return to normal. Suspect if the PS pump belt were removed on a car that did not have steering issues the wheel would still center after a turn.

Of if the car was setup not to return to center the PS system would not be able to override this tendency.

But just a guess.

You might raise the front end up and turn the wheel full left and right. Feel for binding, etc with engine off.

Start the engine and repeat the process.

The steering should be smooth stop to stop with no binding.

 

THanks Toyomoho.