First, apologies if this is a repeat of a much discussed issue. I'm new on this board and a new RX8 owner. I did search for the problem I am seeing but nothing real substantive.

I have a 2006 RX8 Shinka with ~39K miles on it. Love the car, have a ton of fun until I get on the highway. I will be driving down the road and all of a sudden the car will wander like 2 feet to the left. While driving on highways with several fixes it will tend to wander a bit more. Now, I've been driving for about 20 years now. I've had a 68 mustang, MR2, ZX2, 240-SX, SEVERAL Accords, and a Saab 9-3, and I've NEVER seen this kind of behavior. At first I thought it might be either the 40 series tires are catching, but that doesn't seem to be it. I did run over a road hazard and put a hole in my sidewall. Thereafter I got the alignment redone. I had it double checked by Les Schwab as well. Still, this issue persists. I can remember driving on some road that was pretty rough in other cars, it'll be bouncy but the car never moves with me white knuckling the steering wheel.

Just this week when I was driving in to work, it wandered quite a bit. It's to the point that I am literally white knuckling the steering wheel. Love the stereo system (although I aim to improve on it), but I can't even enjoy it as I'm focusing too much on the road. Changing lanes, yeah. Hate to do it. The other odd thing, when I take corners fairly hard, and I don't disengage the active suspension, the right rear tire will catch. What I mean by that, is I will literally hear it catch almost like during the turn the wheel catches. The car tends to hesitate a bit there. Now, I do have snow tires on the rear (studless blizzaks) and regular tires on the front. Not exactly an optimal configuration, but certainly should not necessitate this degree of play.

I've consider ball joints or the rack and pinion steering, but not really certain if that may be it. If anyone has any suggestions I would LOVE to hear them. I LOVE driving this car, and at some point I'd like to give it to my daughter but not like this.

Also, if I do need to get to get the car fixed anyone know if this would be covered on warranty? I had heard the warranty was extended on these and typically I won't buy the extended warranty from Dealers since every car I've owned that would have been pure profit for the Dealers and Warranty folks.

Thanks in Advance
--Matt

 

try switch tires
when it wanders, does the steering wheel turn?

 

1) Very bad idea having different tires on the front versus the rear. The handling of the car is based on a 50/50 gravity distribution and you are throwing that off.

2) Get under the car and check for anything that looks out of the ordinary (you portray yourself as experienced so I take it you know what to look for)

3) If you can't find the issue, i.e. all else fails, take it to the stealership


Good luck

 

explain

please

 

^....was wondering about that statement as that as well! (WTF does that mean?)
Also, it should go without saying.................you have checked the pressure in all tires and they are the same?

 

btw Matt- you mentioned Les Schwabb. Are you any where near me?

 

Back in the early spring I installed a suspension on my 8, as well as new 19's with new tires. I took it and had an alignment done as best as possible. I knew the camber would never be correct with the car being lowered, but since we know that toe wears tires more than camber, I told the alignment guy to simply max out the camber as far positive as possible, then set the toe correctly.

Well, as time went on and I drove the car, I noticed that in certain areas of road near my house, the back end would twitch and pull side to side. It was a lot worse when it was raining or the road was wet.

Finally I decided to check the alignment myself using some home made tools. Many small race teams use this method to align their cars and depending on your tools and methodology it can be more accurate than a computer alignment (or obviously much less accurate).

Well when I checked the rear toe I discovered the problem. Instead of the normal 1/8" or so of toe in (or toe out, depending on your preference) I had...





wait for it...






wait.....






not yet....








13/16" of toe in on the rear tires. Yes, almost an inch of toe in.

Yes, it wore those new tires BALD on the inside in under 2000 miles/9 months.

I'm currently getting ready to re-align the car by hand myself, I think I can obtain a better degree of accuracy than that myself.

So in summary, if the car drives unexpectedly on the road, look at the road, tires, and mostly the alignment.

 

Sorry for the late Replies. Holiday season and all. So what I mean by wandering is as follows. I drive down what seems to be a normal highway road (I-405) from Redmond towards Bothell. I am right about 3 feet from the right hash mark in the fast lane. Steering wheel does not move, but car moves 2 - 4 feet to the left. At this point, I've soiled my BVD's!!!

Ever since the Steering was recalibrated by Les Schwab (righ rear wheel camber was a bit high), changing lanes has not been nearly as bad. Historicaly, when you changed lanes it would be something that took every bit of your awareness. You would begin changing lanes, and if you were not careful, the car could jut hard into the next lane. I soft of liken it to the way it would feel when you drive on old pavement, and they have just laid new pavement in the next lane this is 2 - 4 inches higher. It can be done, but it takes a great deal of control and concentration.

Now, to be clear... I AM NOT a mechanic. I am an engineer. I have switched out a few engines... 20 years ago. No, I would classify myself as barely Novice. Just dangerous enough to do damage if I get arrogant.

There was a suggestion of taking a hard look at the undercarriage. I did have Les Schwab in Snohomish, WA do so. They had redone the alignment again but said to me, "This thing should be cornering like it's on rails". It does, if you are under say 60 mph.

I have specifically asked about tie rods, alignment, and am now considering ball joints.

Oh yeah, the tires. I have considered the delta in the tires as being the culprit. I am pretty close to going and spending the money to go and get the front tires to make em all match. Only deal is, the degree of play I'm seeing makes me suspicious of that conclusion. Then again, I could be completely wrong here.

So the other thing, when I am driving around and I corner hard. If I have the active suspension engaged (DSC), the rear passenger tire may catch. Kinda sounds like the tire just stands up and all the tread catches. Not sure what would happen if I pushed through that... Frankly, I don't really want to find out either.

Oh yes, the Admin had asked if I live in the area. I live in Snohomish. I did buy this car from a dealership in Portland, Wentworth. Know anything about it.

 

sounds like tie rod bushings, you need to get under there see any play in the suspension.

 

No.

This sounds to me like simple tram-lining.

Before you start messing around with suspension components, I think that we need to take a hard look at your tires. Let's start there.

Who manufactured them and what model are they? How many miles are on each pair? When you had the one tire damaged, did you replace only the one, since a sidewall hole can't be fixed? If you replaced only one, then how many miles does it have compared to its mate on the other side?

From your posts, what I have gotten as possible issues are that you are running a hard compound tire, like a bridgestone Potenza, which tramlined on me terribly when I had them. (Let me define. Tram-lining is when your tire catches an imperceptible rut in the road that most tires would just conform to, but since the tire is hard, it catches the edge and jerks the car to one side or the other quite hard. A different tire can eliminate tram-lining entirely.)

Second, if you replaced one tire on one side, with a more worn tire on the other, that can lead to wandering, road noise, poor handling.

Third, the snows on the rear only can cause some poor handling, but I don't know if your description would jibe with that. I have always gone with all four.

Fourth, the allignment that you got might be wrong. It happens more times than you would think. A toe out on your tires can lead to wandering, but perhaps not the type that you describe.

I would start with the tires, before I would think of anything else that would be more expensive.

 

OK... So on the Traming thing. The front tires are Bridgstone Potenza's. The rears are Blizzak's. Les Schwab was mentioning the inflation was high, but it was within specifications (37PSI). I know it should be 32 but from what they said, this is acceptable. The tires that I had on the car when I bought it had about 20K miles left on em, I asked.

When I got the Blizzak's on, the next day I had the highway issue. Thus there was not a great amount of time on them. I did have a buddy of mine drive drive the car around and he said the following:

The car was pulling to the left and to the right. It doesn't have any real pattern set to it and it isn't going to one just one side. I thought it could be the steering box, but if it was the steering box it would only be one way. This seems like someone maybe hit a curb with it and destroyed some bushings. I think you should bring it to a Mazda dealer and have them replace your front A Arm Bushings.

 

tramlining at highway speed?
tramlining only happens when the road surface is not flat, and you can feel it thru the steering wheel when the wheels trying to turn the it.

 

Depends on your highway surface. If you live in an area where they use just plain old concrete the chances of ruts for tramlining are very low, but I live in an area where they use a soft asphalt like system. It ruts after a few years and tramlining becomes a big thing on the highway.

It is true that you feel the steering wheel jerk in your hands when that happens, and this guys doesn't feel that.

 

OK, without having driven it and from your friends description and yours, I'm saying that you have a toe out alignment. This happens more than one would want from professional alignment shops. Take it somewhere else and have the alignment checked. My preference is always NTB if you have one nearby. They invest the most money in their machines. The problem with taking it back is that once a shop does it wrong, they generally don't know what right is.
Anyway, that's my best guess, but I do not claim authority. It is also probably the cheapest thing that you can try.

 

Also try lowering your tire pressure to 32 PSI, that isn't helping matters very much having them over inflated.

 

stock pressure is 32 psi ...

 

ok?

 

First thing I would do is change the tires....borrow a set or something and see if that helps...I would try and get a stock set and use those. That will rule out some of the tram-lining issues on wider than stock tires and offsets, as well as the effect that different tread patterns can throw in the mix

If that helps but you still have problems...get it aligned at someplace that has a clue...they will also check you tie rod ends and suspension play in the ball joints etc..so you will know what is going on there

I doubt that it is anything else......BTW..tire pressures are more important than many believe....keep those puppies inflated properly

 

From what you said, you feel that suspension is tight, but it's fairly easy to jack each tire off the ground, and kick around wheel to see if anything is loose.

I ran on the track with slightly larger tires in back, the traction control locked the rears ahead of the front, and spun me out 360 degrees at 30mph. The manual says it can happen with mismatched tires.

So I turned the traction off, and hung out the rears the rest of the day.

I think you should turn traction control off, and drive carefully to test, until you can get 4 tires alike.

 

^ Great advise...turn the TC off on a car that is acting strange

 

I don't think this is due to the highway. I have driven 405 plenty and I-5 and I don't get the same experience.

What are the sizes of your tires? This car has traction control and different diameter tires will cause all kinds of crazy behavior due to the difference in wheel speed. You have snow tires on the back and I would expect snow tires to have a higher sidewall ratio and a larger diameter.

If that's not it:


I think you should take it to tru-line suspension to have them inspect your alignment, suspension and tires.

http://www.trulineseattle.com/

They do an excellent job, can give you a high precision alignment, and can inspect your tires.

That's where I bring my car for alignment and advice.

 

Is the OP local to Seattle? Sure there is someone that will help you out...lots of great Seattle guys

 

reading comprehension Dan

 

Bite me Merry Christmas

 

Uneven tire wear and improper alignment will cause this issue. Best thing for you is to get a complete set of new tires and a 4 wheel alignment.