Twitchy steering at freeway speeds.

I just returned from a San Diego Prius Club meeting. There I met a guy that says he's cured his wandering problem. He says it is something relating to the power steering. He then went on to say something about adjusting toe-in a certain way which didn't make sense. So I've asked him for a copy of the alignment numbers on his car. He also says he had to add 20 lbs to the front end of the car and remove all extra weight from the back????!!!!! I think he's actually hung two 10 lb weights somewhere out ahead of the wheels!!! He didn't seem all that technical about the solution so I'll have a look at the alignment numbers when I get them.

But he did say that if you call Toyota about a problem, by law, that have to let you know (if you ask) how many other similar complaints they've had. According to him Toyota has received 3800 complaints of wandering/wiggling at high freeway speeds for the 2004 Prius. Thirtyeight hundred!!!!! I don't think they can say that they've never heard this problem before. I drafted yet another letter to Toyota giving them one more chance to convince me they are even concerned about this before I go to the NHTSA. I really don't want to do this but I want to feel safe in this otherwise wonderful vehicle.

 

It'll be interesting to see what resolution he came up with. The old weight transfer thing, is a very very old technique to cover up wandering on old non-aerodynamic cars that used to experience a lot of front-end lift at freeway speeds (remember the Corvair?). Since we have very aerodynamic cars, I think that the alignment settings are probably more responsible to any real change.

By coincidence I also went on a long freeway ride this weekend (Gilroy Garlic Festival) and found that my twitchiness was not noticeable at all. The steering stayed on center and returned to center by itself, none of that constant wiggling that it used to have. I have not done anything other than the aforementioned tire pressure change to 44 front and 42 rear.

I am now more inclined to believe that its just a tire issue and am looking forward to changing them out for a set of ultra high performance, low-rolling-resistance radials as soon as I can justify them to the boss. :wink:

If I remember correctly, you can compensate for a tire that exhibits excessive compliance (the wiggling that I think we suffer from) by increasing tire pressure and by cranking the toe-in (alignment). Unfortunately if you exceed factory specs, this will cause excessive tire wear (feathering) which is why the dealers are probably not doing it.

Lets hope for a speedy resolution.

 

I wish I could report similar results with my car. At 42/40 VS 35/33 the wandering is much more noticeable. I've gone up to 44/42 as well. As much as I hate to lose the approx. 3% increase in gas mileage, I've found the 35/33 to be much more stable. Not perfect, but better. I know some like you that say the opposite and others that have found the same as I have. And it's pointless to argue which is right really. The lower pressure might cause the contact patch to trail a bit more. And more trail leads to more stability, which is what you're after if for instance you could increase the caster. But then again you might get less side wall flexing with the higher pressures. Either way I would not think it would be a drastic effect, and I don't think it is at least in the case of lower pressures for me. Just slightly better.

Yes I'd like to think it's tires also but I'm just not sure at this point. And at $400-500 a set I'm not ready to experiment until I find the right size and model of tire...yet that is. I might be going on a long trip soon and if that happens, I just might get some Michelins. Probably the energy ones. and the 185 65-15

 

FredWB,

The contrarian nature of your reports are interesting. It sounds more like you do have an alignment problem/defective tire/bushing, etc. if the increased pressure doesn't help or even makes things worse since radials do not change shape too much with pressure changes (compared to bias ply tires, of course).

I just thought that maybe you could go to one of those tire places that offer a 30 day free trial on tires. I don't remember if it was a store policy (America's Tire Company/Discount Tire) or if it was a manufacturer offering (if no Michelin, then Yokohama ES100, Toyo Proxes TPT are supposed to be LRR according to the respective manufacturers). That way you could go on your trip and see if there was any difference.

Big improvement = Happy Camper, no improvement = return tires at no cost, and more data for Toyota 'cause there's something in there they gotta fix.

I wonder if there is more than one contributing/compounding factor(s)? I guess that I'm just hopeful that there is a solution (or two) out there for us.

 

So far, I have had an alignment performend and purchased a set of Michelin Hydroedge tires. Although the handling has improved, the wandering is still there but definitely not eliminated. I have tried different tire pressure settings from 44/42 down to 35/33 and in my case found that the 38/36 works best. At the higher tire pressure my car tends to wander more.

In summary, the handling has improved tremendously (not exaggerating) at the expense of 5% less in fuel economy, but the wandering is still there. For those of you that have not experienced this, in my car's case, if I take my hand off the road I could find myself veering into the next line.

I hope this post helps.

 

After 3 alignments by the dealer where they tweaked the toe in each time and two checks by outside alignment shop (one the non-computer method) you would think the alignment issue has been put to bed. But if I look at the results, they're all somewhat different. The last shop said the camber was out from the right side but within spec and toe in was OK. They didn't think it would cause this but said they could put it in the middle of the tolerance like the left side if I wanted to later on.

One shop showed the left frt toe to be .05 def, right frt .15 deg and the left rear .05 deg and rt rear .20 deg. This was right after the Toyota dealer said they were .05, ,04, .23 and .19 respectively. The rear toe has a lot more tol compared to the front at -.2 to .2 for the front (about .05 recommended) and .05 to .55 for the rear. I don't know if the nom of .3 deg is what's recommend for the rear or not. If I look at all of this it seems the rear toe on the left side according to the dealer is right at the minimum. Maybe I need to go to one other computer alignment shop that was recommended to me for yet one more opinion. At this point I feel that I'm chasing a ghost!!

 

just a thought Fred have you tried a bigger differential pressure spead. What I mean is 40 34 maybe 40 35 front to rear and see if it makes a difference. It might help or it might make it worse but if it makes it worse decrease the spread. I'd probably go 36-33 to start and then go to 37-33 then 38-33 and see. You've been working this for a long time and a few more experiments might take you in the right direction.

 

No Frank but I will try that, thanks. You know I've heard this power steering issue from more than one source now. It may have become urban legend or there may be some truth to it. The last gentleman said something about the power steering assist switching off at high speed and something else about excessive play in the power steering unit. I didn't have any time to talk with him further but gave him my email address. I'll be very interested to see his alignment numbers as well as query him further as to exactly in what order he did things and why he added the weights. Seems like nothing he found really fixed it and he had to add the weights to overcome some geometry issue. I remember him saying something about the nose of the car being two high and having to remove all weight from the back of the car. He also implied that only package 7 and below had this issue which makes no sense at all to me, especially since I have package 9. That's most of the reason I don't give much of what he said any credibility yet. But we'll see. He claims to have fixed the wandering on his car. It's kind of bad news that the owner that put hydroedge tires on has not totally resolved his wandering problem either. I suppose I could just sell the car and recoup most of my investment but I do believe in the hybrid concept and love the car otherwise. I just wish Toyota, as well as other car manufacturers, could be a little bit more honest and forthcoming with owners when they know there's really an issue. I guess we all have lawyers and sue happy people to thank for that.

 

Boy, all of todays posts sort of put the problem all over the map. As you said before, there are some things that work for some people but not others. One thing that struck me about your post today was that soemone said that the power steering turns off at high speed?

This is interesting because this weekend's long ride for me felt different. Since it was the first long ride at 44/42 I assumed that was the change that made the wandering seem to go away for me. I did notice that the steering felt very heavy at speed. I did at one point notice it while driving and just two fingers to try and drive the car. The steering was so heavy that I could not drive it that way. Thinking back to when it was twitchy, it had to have both hands on the wheel at all times, and sometimes even got my knee on it just to relieve some of the stress on my arms.

Since I've done nothing else, I wonder why it just started working all by itself? I also wonder if this isn't a slighly more likely culprit since no one has been able to factor it out?

Is this something that one of the club members can check out with a mini-scanner?

PS. I also have a pkg9 and when the problem existed, it took the car all over the lane I was in.

 

Now that there is no clear indication of one single item possibly being the sole culprit, I went through a few old posts on Yahoo Groups and found some of the same complaints for the first gen Prius. The most common answer was to get the car properly aligned, but there ws this post that added something that really grabbed my attention:


"Well, it's a matter of training. You've become accustomed over the years to vehicles which have a large 'dead spot' in the motion of the wheel, so you've (subconsciously) trained yourself to move quickly through the dead spot then make a minor steering correction. Many of us went through the same learning curve, or is it 'retraining curve'...

Some of it could also be alignment. You want it set for 0.05 DEGREES toed IN on each side - TOTAL toe IN of 0.10 up to a maximum of 0.20 degrees. This is a tighter window than 'factory spec', but well worth having checked!

Let us know how it goes...
Pete (3+ years, fully retrained)"

http://autos.groups.yahoo.com/group/toyota...s/message/68128

Having owned exotic cars for asome years, I have found that the only place that would do an alignment correctly for me is a shop that primarily specializes in racing cars. After having my cars precisely aligned front and rear, those cars never bothered my again. Maybe if a few of us go this route, we could get some more useful data. These shops sometimes have people that really know how to drive and their opinion could potentially be a big help to us.

 

Yes I do agree that the Prius doesn't have this large dead spot. In fact it's got no spot it really prefers it seems. We used to refer to cars that had a dead spot as cars that tracked well. My wife's RSX Acura is like that. It goes straight very well. But the short wheelbase, wider tires, and stiff suspension all contribute to that confidence you feel in the RSX. Even the road grooves don't seem to pitch it off course. It just flat out tracks. You can feel confident that if you take your eyes off the road for a split second to change the radio station, the car will never do anything unpredictable unlike my Prius. Note I didn't all of them.

So I do think the soft suspension, rather tall profile, lots of side area for the wind to act against, narrow track and tires, and long wheelbase all contribute to the lack of a LARGE dead spot. These things are not a problem in and of themselves. They're just characteristics of the car that accentuate the problem.

But try as I might, and I do try, I can't seem to always know where it's going to go and when that happens I sometimes find myself at the edge of the lane. A large fast correction will cause the car to end up at the other side of the lane so I try to lightly and gradually bring the car to the center of the lane. If I'm too light or slow, then I'm hitting the land dividers. So it's a very tiring experience driving around traffic and not at all a re-training issue in my opinion. With the soft suspension I can actually feel my head rock back and forth and the car has actually made my wife car sick. When I drove it from San Diego to Vegas my arms hurt from the constant steering necessary to keep it going straight. There was plenty of wind and trucks to contend with on that trip.

 

Howdy,

Well folks put me down as another wandering Prius. I have a Silver #9 with approximately 3,900 miles. I cannot take my hands off the wheel without darting to one side or the other. It can be either direction and it is immediate and so subtle that if you are distracted (e.g., adjusting the HVAC) you are off the road before you notice!

I am just starting to play with the tire pressures etc. I will mention the wandering when I have the 5k service done; not much hope for my dealer options are bad and worse....

Tom & Da Boyz

 

Perhaps this is a safety feature to encourage you to pay attention! :wink:

 

It's a safety something that's for sure! Don't hesitate to at least tell your dealer and make sure it goes on record. I think there are too many of us that are not bothering to say anything and just assuming that's the way it is. Stilll, having heard from 1800 owners, if that's an accurate number, tells me that Toyota has some knowledge of this. What they're going to do about it, if anything, is a guess. I just hope they're not going to wait for some event like a major accident, where someone is killed, to finally do something about this. That's assuming something can be done and it is not a FEATURE!

I have yet to hear back from them on my latest complaint and I'm going to yet one last alignment shop to get them to set the rear toe in closer to the nominal .3 deg in an effort to reduce the wander and also recheck the front toe-in. I think it's out left to right at the back and probably as high as I want to set it at the front without loosing some gas mileage (about .05-.06 deg).

After that, without Toyota's help I only have three other options. Correct the rt front camber which is out from the left. Not a likely solution. Put on a new set of Michelin tires. And finally, sell the car if at that point I'm still not satisfied. I guess I'll just have to play all my cards and see how good I can make and then decide. I really don't want to sell it and think it can be made better than this.

 

I just had the alignment checked for .....lets see now...the 6th time maybe. All that came up this time was the right frt camber being -1deg and the left only about -.6 deg, which I knew about. So I had it fixed this time. They had to slot a suspension component to adjust this which is typical. Otherwise I have about .05 deg left and right toe in and about.2 deg on the back. And the car still is a handfull on the freeway. Toyota has not acknowledged my email this time like they did when I first mentioned this problem except for the automated reply, so I plan to call them tomorrow. I think I can probably rule out any alignment problems at this point. There's just nothing an alignment shop can do differently. So is it tires, suspension bushings, steering rack or what?????

 

Fred, have you swapped cars with someone who doesn't feel they have this problem, driving the same roads, at the same time? I'm all for scientific experiments. I paid a lot of attention to the rental car yesterday, with your problem in mind as it does cause some concern for potential buyers. I didn't have to fight to keep it in the lane, but a small movement of the wheel did result in a nearly immediate response, not much "dead band". If it were a sports cars, I think it would be described as having "tight steering" and deemed a virtue

 

Yes I agree that under some conditions, the steering is quick and appreciated. Under say 50 mph I love it. And mostly on smooth asphault without any high cross winds it's not so bad, just immediate and quick.

I did do the switch with Henry E. as I stated but have not had the chance to to drive his yet. He drove mine and his son drove next to and around us. His car at least looked rock steady while mine seemed to wiggle around. This was especially noticeable to Henry above say 70 or so. He did not notice anything at first and that's my experience, you really have to drive it a bit. I did drive another one, Toshi's, the guy that got everyone the EV buttons from Japan. I only drove it at lunch, on one freeway ramp and off a couple ramps later. It seemed OK to me but I think it was too short of a drive and not over the right road surfaces. I don't recall if it was windy that day either. Just last week he said his wife complained about his car being tough to drive on the freeway and wiggling too. He never noticed it before that he said.

 

O.K., this thread is officially freaking me out. The Prius is one of my top choices for when I buy a new car this fall, but this highway steering problem is really scaring me away from the Prius now. When I hear the descriptions of the problem, it just flat out sounds like the Prius's 70+mph highway stability is dangerous!

For those who have the problem, you have my greatest sympathies and I hope you get this problem solved quickly. In fact, how quickly this problem is resolved will probably determine whether I myself will be ordering a Prius. I hope the tire replacement plan some of you are trying will work.

 

Kerensky, the only problem I've had with "wandering" is at a certain stretch of freeway near me (about 1/4 mile long) where the grooves in the concrete make my car feel unstable. However, my '91 Camry wandered at that spot as well. Even though 1,800 prople have reported a problem (and Fred certainly has done all he can to correct it), we don't know how many of those 1,800 TRULY have a problem. Maybe their alignment is out, tire pressure is messed up, etc. Not everyone is as knowledgeable as Fred and others who follow the Prius groups, so I think the number of real problems might be less. You're far more likely to get a stable car than an unstable one. I knew about the stability problem that some people were having, and it didn't deter me from purchasing the most fabulous car I've ever had!!!

BTW I acknowledge that re-striped freeway lanes or road construction that forces you to ride the expansion gap between lanes can cause the Prius (or ANY car) to be unstable. It's a great car, but your feeling of safety is the most important thing. Does a dealer near you have a TRAC car you could rent? I've heard that Enterprise and maybe Budget have Prius in their rental fleets. It might be worth the investment to rent one for a few days to help you make up your mind.

 

Kerensky,
While I would certainly not despute any claims about poor handling cited by others in this post, you should realize that it seems to be a very small minority who are having problems. To my recollection of the posters, I think that the ones who have actually had complaints here can be counted on one hand. This Chat board is approaching 3000.

This suggests that this is a problem isolated to a few specific vehicles rather than a more general design fault in the Prius Model.

Just my 2 cents. No handling problems with ours.

Jon