The Truth About Cars » Power Steering http://www.thetruthaboutcars.com The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. Wed, 23 Jul 2014 18:25:17 +0000 en-US hourly 1 http://wordpress.org/?v=3.9.1 The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars no The Truth About Cars editors@ttac.com editors@ttac.com (The Truth About Cars) 2006-2009 The Truth About Cars The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars » Power Steering http://www.thetruthaboutcars.com/wp-content/themes/ttac-theme/images/logo.gif http://www.thetruthaboutcars.com Saturn Ion Steering Woes Focus Of NHTSA Probe http://www.thetruthaboutcars.com/2014/03/saturn-ion-steering-woes-focus-of-nhtsa-probe/ http://www.thetruthaboutcars.com/2014/03/saturn-ion-steering-woes-focus-of-nhtsa-probe/#comments Fri, 21 Mar 2014 12:45:53 +0000 http://www.thetruthaboutcars.com/?p=776793 2007 Saturn Ion Red Line

One of the handful of models already under recall by General Motors over a defective ignition switch, the Saturn Ion faces additional scrutiny by the National Highway Traffic Safety Administration over failures traced to the vehicle’s electric power steering.

Automotive News reports the NHTSA received 846 complaints from owners of 2004 through 2007 Ions over the steering system, alleging a sudden loss of power steering due to a build-up of brush debris combined with oily material disrupting the system’s motor’s operation. The same issue affected the Chevrolet Cobalt and Pontiac G5, as well — all three shared the same steering system — leading to 16 crashes, two injuries, and a 2010 recall by GM of over 1 million vehicles.

However, the Ion was not included in the 2010 recall, nor did the NHTSA force GM to do so citing lack of sufficient evidence, moves National Legal and Policy Center president Peter Flaherty had trouble understanding as noted in a letter to CEO Mary Barra written this week:

We cannot understand the delay in recalling Saturn Ions, particularly in light of your recent statement that the ignition switch recall “took too long.” You also stated “terrible things happened.” An immediate recall of Saturn Ions will prevent additional “terrible things” from happening.

Though GM offered Ion owners a warranty covering the system for 10 years or 100,000 miles in lieu of a recall, 382,000 Ions would be included in the additional recall.

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Piston Slap: Better Steering without the Better Car? http://www.thetruthaboutcars.com/2013/06/piston-slap-better-steering-without-the-better-car/ http://www.thetruthaboutcars.com/2013/06/piston-slap-better-steering-without-the-better-car/#comments Wed, 05 Jun 2013 11:20:21 +0000 http://www.thetruthaboutcars.com/?p=490520

Oliver writes:

Sajeev,

In December of 2011, through an unfortunate chain of events, I became the not-so-proud owner of a 2007 Malibu. True to its origin as an ex-fleet car, it is saddled with the miserly 4-banger engine rather than the still-slow-but-adequate V6. The only positive attributes of this car are its cheap cost to own and excellent fuel economy for its size. It presently has about 80,000 miles on it – I expect to get another 40K out of it before the transmission implodes (domestic automatic – you get what you pay for).

Currently, my wife is driving it (poor woman deserves a medal) – despite the obvious untenability of this situation; her only complaint is that the steering feels “loose.” We recently took a trip on a highway and I verified that the steering wheel feels like a cheap arcade wheel from the ‘90’s, to the point where it almost seems to turn itself (much like the platter on an Ouija board).

Our mechanic took a look at the steering system and found nothing amiss. Since I don’t believe a car this boring could possibly be home to a poltergeist, and since the system is “functioning as designed” (that’s corporate-speak for “stinks like crap because it IS crap”), I am at a loss for what to do.

I don’t want to invest a lot in this car – it’s an appliance – however, we live in NJ (land of a thousand potholes) and I am worried that the loosey-goosey steering combined with the abysmal condition of the roads here represents a safety concern. My wife has to maintain an iron grip on the wheel to keep from swerving into the other lane on her back-road-heavy commute.

It is worth noting that I have replaced all four struts, brake pads (incl. grinding the rotors), and tires on the car in the time I’ve owned it, and the mechanic found nothing amiss with suspension when he was looking at the steering. The thing drives pin straight until a mosquito farts near the steering wheel.

Is there a reasonably inexpensive (say, sub-$500) way to tighten up the steering? We’re not looking for euro-spec here; just a little more feedback.

Selling the car is not an option – we are not in a position to pay the transaction cost (and there’s ALWAYS a transaction cost to buying a new car), and it fits our needs nicely except for this one issue.

Sajeev answers:

Awesome letter: very TTAC-snarky, to the point that Farago would be proud. Now is tighter steering possible to an extent that people–those who can’t measure mosquito farts–would actually notice?

Subjective matters are just that, but KUDOS to you for already replacing the shocks: an often ignored element in old car ownership. Yet there are a handful of steering parameters you can check/adjust to improve steering response on any vehicle, especially used ones.  In no particular order, and for ANY vehicle:

1. Replace used steering box/rack and pinion assembly.  Why? Because these are wear items, even if they don’t show an external leak or excessive play measured by your trusty mechanic.  And they wear out so slowly that you will never know until its reached this point. We are literally splitting hairs when we discuss tighter steering, so 80,000 miles of wear easily fits into that gray area you must consider.

2. Do a performance wheel alignment, tweaking the factory specs. Read this and discuss with an alignment tech that tunes race cars. If needed and if available, get a set of aftermarket caster-camber plates.

3. Get higher quality tires, use summer tires when possible and play with tire pressures in +1 PSI intervals, front to back.  (Don’t go crazy here, more than 5-10PSI increases probably isn’t a bright idea.) You already have new tires, but remember, you sometimes get what you pay for.

4. For older vehicles with conventional power steering pumps attached to the front of the motor, check out that pulley at the end of the pump.  Underdrive dat pump!  With a fair bit of analysis of other GM products, I suspect you can find a “better” power steering pulley to firm up the steering a bit FOR CHEAP…but perhaps a slower spinning pump won’t change your particular problem. I’d bet on this being the best bang for the buck, however.

5. Get wider wheels/tires!  Not cheap, but these can be sold separately from the car when the time is right.  And if you can find a wider OEM wheel that interchanges, that just makes the conversion cheaper and a touch more stealthy.

Good luck, whatever you may do.

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice. 

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Piston Slap: The Heat Is On! http://www.thetruthaboutcars.com/2012/07/piston-slap-the-heat-is-on/ http://www.thetruthaboutcars.com/2012/07/piston-slap-the-heat-is-on/#comments Mon, 16 Jul 2012 11:21:54 +0000 http://www.thetruthaboutcars.com/?p=452829

 

 

Ramin writes:

Sajeev,

I am not a TTAC member, but I read it almost daily. I suppose I should join soon. Anyway having read your “piston slap: we need your help” post, I have one that has been stumping me for about a year now:

The car is an 08 Impreza STI. For the past year or so, the power steering struggles and whines. It is much worse when the car is cold, doubly so when the weather and the car are cold. There is no belt squeal. I have tried flushing and bleeding, both with factory fluid and also with the Lucas stop-leak stuff. Modest initial improvement only lasts a little while. Subaru forum posts suggest the STI cooks its PS fluid because the fluid lines route near hot turbo components. However it seems now even with fresh fluid, the problem persists, leading me to suspect a component has gone bad. I don’t want to drop over $600 for a new pump. Are there any tricks you know of, like for example, replacing a particular gasket? Or, better yet, some advice on narrowing down exactly what the culprit is (short of replacing the whole freaking pump)?

Thanks a lot and keep up the good work – I love the site and what you all have done with it.

Sajeev answers:

Thanks for your kind words.  I never thought that an unemployed (Lincoln) forum moderator could eventually be the ring leader of this crazy Piston Slap thing I created. Apparently my unemployment period was good for me, and perhaps it enriched/enriches your life. So there’s that.

I am a little concerned you put Lucas Stop Leak in a system that never leaked: stop leak products tend to gum up areas that don’t need gumming.  But that might be unfounded, go ahead and verify on the forums. In general avoid stop leak products unless you 1) have a leak and 2) really don’t give a crap about the leaky vehicle in question.

I think the knowledge you gained on the forum is right.  The fluid lines are in an unfortunate location, and Turbos make a TON of heat.  There are two things I’d recommend:

1. Switch over to a racing grade Power Steering fluid, if it has a higher boiling point than the stock stuff. Several oil companies supposedly offer a fluid with a higher boiling point, as googled here. I will not speculate or endorse one over the other, and I am sure the forums have already covered this.

2. Protect those steering lines! You need to shield them from the turbo’s heat.  I would use an insulating heat shield wrap for the lines, and possibly make a sheet metal sleeve in this general area, to further help isolate the lines from the Turbo.

Why am I saying this?  Because I’ve raced a couple of late model Corvettes, and they do suffer from clutch fluid problems in a Texas summer with a hamfisted AutoJourno behind the wheel.  So do them both. The same thing applies here, especially when we talk the heat of a Turbocharger in a tight Subie engine compartment.

 

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.

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Who’s Afraid Of Electric Power Steering? http://www.thetruthaboutcars.com/2010/02/whos-afraid-of-electric-power-steering/ http://www.thetruthaboutcars.com/2010/02/whos-afraid-of-electric-power-steering/#comments Wed, 10 Feb 2010 20:38:56 +0000 http://www.thetruthaboutcars.com/?p=344856

Here’s a challenge: try to find a review of the Toyota Corolla that doesn’t bemoan its numb steering. Now try with a Chevy Cobalt. Or a Venza, or Vibe, Or Rav4, or Equinox. What do these vehicles have in common? Column-mounted electric power steering systems from JTEKT, a Toyota spin-off supplier which has done a brisk business in these fun-eliminating steering systems. And though the motor press has been bashing electric power assist steering (EPAS or EPS) for its deleterious effect on handling, the explosive growth in these systems may put more at risk than mere enthusiast-approved steering feel.

This anesthetization of steering systems has not taken place because manufacturers appreciate the proliferation of words like “numb” and “overboosted” in reviews of their products. EPS offers improved efficiency due to its reduction of parasitic losses, and is cheaper to manufacture than traditional hydraulic systems. This killer combination offers manufacturers a combination of improvements that have proven near-impossible to resist, resulting in the broad proliferation of EPS systems. And if reduced steering feel were the only casualty of the switch, it would be a tradeoff that any manufacturer would be willing to run.

But as EPS has exploded onto the market, a number of troubling issues has plagued the system. The National Highway Traffic Safety Administration has opened investigations into the Chevy Cobalt and Toyota Corolla, which share the column-mounted JTEKT EPS system. Cobalt, which moved to an EPS system for the 2005 model year has been haunted by an accelerating number of failures since the switch, while the Corolla investigation centers on Corollas built since the 2009 model-year switch to EPS.

In both of these vehicles, pinning down exact steering defects is proving to be difficult. Many of the Corolla complaints are related to sudden veering, particularly at speeds above 40 mph. The Cobalt, meanwhile, seems to experience complete EPS failure, causing momentary loss of steering and/or the need for drastically increased steering effort. Again, the inability to stay in a set traffic lane is being targeted as the most dangerous symptom of the possible defect.

These symptoms fit conveniently into a category that an early report (by Amit Rohidas Bendale of the Vishwakarma Institute of Technology, publication date unknown) on EPAS technology posted at college-seminars.com calls “auto steer,” a term the paper asserts “has crept into the lexicon as an adjunct to the development of EPAS system.” Bendale attempts to explain this phenomenon in his paper’s section on the disadvantages of EPS thusly:

To-date, technical and product liability concerns have precluded the introduction of such systems in the U.S. market through it is expected that niche application may be expected in the near-to-mid term mix of future vehicles. Such system design have yet to prove themselves sufficiently reliable and safe to prevent dangerous “auto steer” events. “Auto steer” has crept into the lexicon as an adjunct to the development of EPAS system. As the name implies “auto steer” denotes an uncontrolled steering event neither commanded nor stoppable by the vehicle’s driver due to catastrophic failure in the electron hardware or software. In truth, these systems are control servo systems, similar in function to aircraft control servo systems, and must have multiple redundancy. Although these new EPAS systems are said to have multiple redundancy , their design and broad application within the automotive industry have been, and will continue to be, subject to economic pressure more extreme then found in the aircraft industry. For instance one obvious safety related item has been universally deleted from such system specifications: a clutch for physically disengaging the reduction gear box and drive motor assist assembly from the host steering system in the event of system failure. This means that a driver encountering an EPAS system failure will have to exert additional force to “back drive” (i.e. manually over ride) the systems reduction gear box and drive motor assist assembly while attempting to maintain control of the vehicle in the absence of normal power steering assist.

Already, the parallels between these EPS issues (which are admittedly theoretical, but reflect NHTSA complaints) and Toyota’s gas pedal issues are plain to see. The first is the issue of economic pressure towards cost-cutting, which leads to the reduction of fail-safes and redundancy. Another parallel is the fragility of by-wire control systems: in Toyota gas pedals, tiny amounts of moisture was enough to cause the pedals to stick. In the case of EPS steering, there’s evidence to suggest that even cell phone interference could cause system failure. This is not to say that these two situations are directly comparable, but both cases indicate that earlier mechanical systems offer few clues as to possible malfunctions of electronic systems. Finally, the most important parallel between Toyota’s “unintended acceleration” and EPS “unintended veering” is the complicated dynamic between the driver and the system at the moment of malfunction or failure. Bendale continues:

Unlike the manual system described above, PAS with the presence of supplementary steering force to that provided solely by the operator introduces additional engineering challenges in terms of maintaining the desired steering linearity described previously. In fact, with respect to steering linearity, a poorly designed power steering assist system may have almost no relationship between the hand wheel torque applied by the operator and the actual required steering force imposed by the wheel or tires. There no longer may exist the uniform, consistent and predictable relationship between the “input and outputs” to facilitate “tactile reference driving.” Restated, the tactile sense of the driver to maintain directional control, and the magnitude and modulation of the “input” force may not bear a direct, proportional relationship to the required “output” force delivered by the steering system. Tactile reference steering is simply not possible with such vehicles. Rather their drivers must continuously engage in “visual reference steering” to maintain directional control. The result is that such vehicles are very tiring to drive for any length of time or distance. Further their drivers are constrained to continuously look at the road. If such driver should look away even momentarily (i.e., to check a rearview mirror or a child in the car), he or she has minimal tactile reference as to the actual position of the vehicle during that period of time. This is dangerous because, depending upon the road topography and condition, the vehicle may have moved transversely in significant amount relative to where the driver thought his or her vehicle was positioned. This can and often does lead to serious trouble.

This helps explain the varying accounts of unintended veering, as the ability to handle sudden changes in steering response varies greatly from driver to driver. Like unintended acceleration, this makes the task of narrowing down the primary causes of EPS failure or malfunction impossible based on recorded accounts alone.

More importantly, this helps explain the link between numb, overboosted and uncommunicative steering and safety. At highway speeds, any failure or malfunction would be registered and reacted to by touch (tactile feedback) before the brain would be able to register visual cues that vehicle control has been compromised. Because of EPS’s deficits in tactile feedback, and consistency between wheel and steering wheel positions, that all-important emergency tactile feedback would be more difficult for even a well-trained driver to interpret, making a crash more likely even if the unassisted steering system were still functioning (as has been reported in certain Cobalt incidents).

This is clearly an issue that companies like JTEKT have known about, as a 2008 paper on EPS [PDF] by a JTEKT engineer admits that making EPS feel like the hydraulic systems the buying public is used to has been a major challenge. Another paper from the JTEKT Engineering Journal [PDF] indicates that on higher-power versions of column-mounted EPS,

sensitivity to such inverse inputs as flutter and brake vibration has become higher. J-ISM [JTEKT's EPS assist control algorithm] has adopted a suppression system that can detect inverse input vibration as torque differentiation value, and by providing assist in the direction of canceling the vibration, the vibration is not transmitted to the steering wheel.

In short, tactile feedback is actively canceled, not only reducing the driver’s ability to respond to an emergency based on steering feel, but also further loading the EPS system with compensation duties in addition to pure steering control.

The point of all this is not to merely raise unwarranted fears about EPS. Improved efficiency and lower costs are the very definition of a successful automotive system, and as long as EPS offers these benefits, its use will continue to grow. As this trend continues, it will be important for safety watchdogs to pay close attention to these systems. Without pressure to include redundancy, fail-safes and extremely robust sensor units, suppliers will continue to cut the cost of these systems to remain competitive with the growing number of firms that offer similar systems. Just as importantly, these new electronic systems require a new approach to safety that pays as much attention to driver reaction to malfunctions as to the malfunctions themselves. Only in this way can we be sure that relatively minor malfunctions don’t yield an epidemic of inexplicable accidents and recalls.

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