You are here: Forums Sedans Toyota Corolla Toyota Corolla Electric-Assist Power Steering (EPS)

Toyota Corolla Electric-Assist Power Steering (EPS)

98 messages,  Last post on Oct 29, 2009 at 2:09 PM

You are in the Toyota Corolla Forum. Your Hosts are pat & karens

What is this discussion about? Toyota Corolla, Steering, Sedan

Messages Page 11 of 11 1 ... 5 6 7 8 9 10 11 Prev Next Last

Go To Msg # Search This Discussion

#93 of 98 Re: Yaris sedan has similar steering issues [dantz] by terceltom Oct 15, 2009 (3:28 pm)
Replying to: dantz (Oct 15, 2009 2:09 pm) I guess I'll start with suggesting that no one should drive "sleepy, drunk or stoned" regardless of what kind of car or steering you have. That being said, yes the Yaris actually had the new EPS technology back in 2007 already, even before the Corollas did. The EPS steering is set up to stiffen up as your speed increases. So when your driving slow, like in the city and trying to parallel park, the steering is very lite and easily manageable.
#94 of 98 steering - improved!! by gerrya Oct 28, 2009 (4:54 am)
For those who share my highway speed steering complaint on the 09 Corolla, here's what I've done: Went to the dealer and booked an appointment for a 4-wheel align on a day I figured they'd not be too busy. Zeroed in the tire pressure exactly to spec on my way to the dealer. Talked directly to the technician and explained specifically and exactly what I was concerned about - fortunately I did that, because the service adviser was totally clueless. Told him that the car had no on-center feel and wandered constantly at highway speed, used the hockey-stick-on-a-basketball analogy. And explained to him in a nice way that I'm not a total idiot about such things - I'm a mech engineer working in auto manufacturing, with over a million miles of driving experience,and that this is my 3rd Corolla.   When he checked the alignment all was within factory spec except for one rear wheel a bit toed-in. We discussed it, and agreed to fix the rear toe-in (it requires shimming, not just an adjustment, so it costs extra) and adjust the front toe-in just a bit so that the car will track straight in the right lane on a crowned road, and most importantly added more caster. (Caster is like the rake on bicycle forks - the steeper the rake, the more the front wheels tends to fall back to center when you let go of the handlebars. Not enough rake, and the wheel won't return to center) End result: steering is very much improved on the highway!! I still find the EPS kind of vague at higher speeds, and I may still go back and get them to crank the caster all the way to the max spec value, but it's certainly workable as is.   Need to bear in mind that one of the last steps at the factory is to do a wheel alignment, and it's done at a rate of about one vehicle a minute. They don't fine tune and tweak your car and then road test it and tweak again till it's perfect - they just adjust it to somewhere within factory spec range and ship it out.   Note that there is quite a range of "within spec" values - if you go in and just ask for an alignment check under warranty, they'll verify that you're within factory spec, but they won't change anything for free unless it's out of range. That's not good enough. Before you give up on the car, pay the money to get a good alignment done by someone who knows what he's doing, and insist that it's complete with a highway speed road test.   It's a $20,000 (Canadian) car, so I figured it was worth coughing up the $165 to get it aligned properly. Mistake I made was I lived with it for quite a while so I opened myself up to the whole argument of whether it wasn't aligned right at the factory, or whether I or one of my kids hit something and knocked it out of alignment (we didn't....).   I'll be interested to know if anyone else gets the same results. Replies to this message: terceltom (Oct 28, 2009 5:41 am) gerrya (Oct 28, 2009 6:34 am) zikzak (Oct 29, 2009 12:11 pm) dantz (Oct 29, 2009 2:09 pm)
#95 of 98 Re: steering - improved!! [gerrya] by terceltom Oct 28, 2009 (5:41 am)
Replying to: gerrya (Oct 28, 2009 4:54 am) Doesn't the over compensation of the front toe-in, to make your car pull slightly left, concern you if you go into the passing lane at 65 mph of a highway. In this case the downward road crowning would be to your left adding to the leftward pull.   The EPS will become more vague at higher speeds as this is it's design.   Perhaps Toyota should just make the specifications more precise so those of you that are experiencing this phenominum would not have to go through what you had to.   Too bad someone with your automotive background and driving experience didn't happen to notice the drift before you purchased the car, you could have asked for this additional adjustment before you made the deal.   Glad it all worked out for you though. While it really shouldn't be necessary for a new car owner to go through what you did, $165.00 is a small price to pay to put this problem to rest for a pleasurable driving experience. Replies to this message: gerrya (Oct 28, 2009 6:34 am)
#96 of 98 Re: steering - improved!! [terceltom] by gerrya Oct 28, 2009 (6:34 am)
Replying to: terceltom (Oct 28, 2009 5:41 am) You kinda have to decide which way you want it to be, I guess. He could just as well have set it up to track straight in the left lane but drift right in the slow lane. Set up the way it is now, it tracks without any effort in the slow lane and drifts ever so very slightly to the left when in the fast lane - but you're not supposed to be out there unless you're speeding or passing, in which case you had better be hanging on tighter anyway. Can't have it both ways.   I do wish I'd done a longer test drive when I bought the car, but I doubt I'd have picked up on it even if I had. The car bounced around a bit on the road, but it didn't strike me as unusual at the time. My 2 previous Corollas were quite susceptible to buffetting from crosswinds, so I put it down to the same thing - it was a typical January winter day in Ontario, not exactly ideal conditions for a test drive. I put snow tires on for the winter, and I kinda put it down to that for a while - snows can affect your steering. But I got concerned when I put the OEM tires back on in the spring and it still wandered. Foolish me, I should have got it aligned much sooner.   There's a young guy working at the same place as me who commutes long distance with an identical car. He has had no issue or concern whatsoever.   On a happier note: I don't know how accurate the in-car fuel economy readout is, but running little over the limit (105 km/h = 65 mph) the economy on this car is incredible!
#97 of 98 Re: steering - improved!! [gerrya] by zikzak Oct 29, 2009 (12:11 pm)
Replying to: gerrya (Oct 28, 2009 4:54 am) That makes so much sense. Thank you for the possible soluation to our problem. I've talked to my wife & daughter about your suggestion, and although the dealer said it was OK during it's last oil change, I will issist on seeing them perform the check....instead of taking their word for it. Again, thank you. Replies to this message: dantz (Oct 29, 2009 2:09 pm)
#98 of 98 Re: steering - improved!! [zikzak] by dantz Oct 29, 2009 (2:09 pm)
Replying to: zikzak (Oct 29, 2009 12:11 pm) My assumption all along has been that these cars were the victims of bean-counter mentality. Some decision-makers at Toyota probably thought that it made the best economic sense to reduce the steering caster to the minimum acceptable level in order to reduce the load on the EPS motor. This would allow lighter steering, a lower wattage motor, a smaller alternator, a smaller battery, lower wattage cabling, etc., and the result would be a measurable cost and weight savings, plus of course a slight increase in fuel efficiency. The flipside, of course, is the unacceptable reduction in directional stability. They made their choice and they took their chances, but it looks like the buyers have noticed it after all, and complained about it, so I'd say that in retrospect it was the wrong decision.   However, I'd be very wary of increasing the caster beyond design spec. It might introduce a whole new spectrum of handling issues. Better to wait until Toyota redesigns the steering geometry so that everything works the way it should.

Messages Page 11 of 11 1 ... 5 6 7 8 9 10 11 Prev Next Last

Go To Msg # Search This Discussion

You are here: Forums Sedans Toyota Corolla Toyota Corolla Electric-Assist Power Steering (EPS)