Car Pulls Left / Right Under Acceleration
 

First,... I'm a rookie with Mazda's, rotaries, and this forum.
Second,... love the car and this forum. Been doing a lot of reading and learning.
Third,... I've done the search thing and can find nothing on this subject.

Questions: Does your RX-8 pull to the right during moderate to aggressive accel? Does it then pull to the left during shifting?

Ours does and it's quite unnerving. I didn't notice this during the test drive. The pulling back and forth is severe enough to have to move the steering wheel left, right, left, right to keep it in the lane as we go thru the gears. All the tires are at the same air pressure at 38 psi.

She's still new and under 600 miles and has not been taken over 6k rpms yet.

Thanks for all your responses.

The steering wheel on mine gives a lot of feedback from the road. My wheel gets kicked around a lot on the streets around my house. Did you try this stuff on different roads? I've never noticed anything llike you've described.

Yes, any time on any road when we moderately to aggressively accelerate. Thanks for the feedback.

Not at all on mine... I would have the dealer check your alignment specs... sounds like you might have some toe-out on the front wheels (I used to do that to my Miata on purpose for better autocross handling, but what you describe can result from it). The 8 is one of the best cars I've had for straight line stability... anytime I've had to let go of the wheel for whatever reason it stays on trajectory.

The only exception I should add is on crappy roads with ridges, deep grooves or major crowns the wide tires on the 8 will make it want to pull pretty hard at low speeds... but that's the nature of the road... not the car.

I cut and pasted this from another thread since I am not all that technically savvy... but maybe this is what you are experiencing...

search the forum for tramlining.


Quote:
High performance tires with short sidewalls that develop lots of cornering power at lower slip angles will be more susceptible to tramlining than standard All-Season passenger tires that develop less cornering force until their slip angle increases. A wider treaded tire will encounter more longitudinal ruts and/or grooves in the road than a narrow treaded tire. A tire with large tread blocks that transmits the driver's input to the road with great precision will also transmit the road's imperfections back to the vehicle's suspension. And because tires become more responsive as their tread depth wears away (which is why tires are shaved for competition and track use), a tire will become more likely to tramline as it wears.

The ruts don't have to be visible, but they are there.


icopus, since you are accelerating and decelerating, you are most likely on local roads, probably stopped at traffic lights. Those areas get very rutted because of the heavy trucks. Their weight, braking and accelerating tend to accentuate the wear on the roads at those locations.

Find an empty parking lot and criss cross it at random angles and see if you still have the issue.

check your alignment and do a search for "tramlining"

Sounds like a trip to the dealer is in order. Wheel alignment? Tire problem? Steering problem?

Torque steer is a front-wheel-drive issue.

38 psi is a bit high don't you think? I keep mine at 32, grips like hell.

I also think the 38psi is a bit high, and if I'm not mistaken the tramlining issues are exacerbated by high psi in the tires. Drop the psi and take it to the dealer. Good luck.

is it a base model?

Are you new to manual transmission by any chance?
I know it may sound silly, but some people subconciously move the steering wheel themselves when changing gear...

Does this always happen on the same piece or road? I have a feeling this could be related to driving conditions, more than the car, especially if it is a new car. I have never heard of such an issue...

Agreed, that's pretty much word-for-word what I was going to say.

And, I hate tramlining!

If you haven't done so already, have someone watch you as you shift under hard accel. They can tell you if you're inadvertantly doing it yourself. Or, try it at a safe place without touching the wheel, ready to grab it immediately if need be, of course...

I have experienced "light" tramlining, but when I went in for the 15K service, it became serious. They re-balanced and rotated the tires. The right-rear became noisy and the car has a mind of its own, pulling to the right sometimes, then pulling to the left others. I've attributed this to my tires wearing out. My plan is to replace them with Goodyear Eagle F1 GS-D3's. Any recommendation on what size would minimize tramlining?

Thanks for all the responses, guys!

Both the wife and I have preferred manual transmissions since we were kids. All three of our vehicles are manual.

I reduced the tire pressures to 32 psi. The dealer had them too high! This helped somewhat, but occasionally, she still pulls back and forth.

Found an empty parking lot, but it wasn't flat. Can't find flat around here. Attacking the lot at different angles, it was obvious the car is pulling to the right, even up inclines. Apparently, the pull to the right is exaggerated during excelleration and the pull then to the left is the opposite effect during decelleration (between shifts).

When the dealer gets the car tags any day now, I'll tell them about this problem.

Again, thanks for all the help, ideas, knowledge, and confirmations.

I don't think what you are describing is tramlining.
Tramlining is worst when you are driving in a straight line, partial or no throttle, and the vehicle wanders off to the right when you take your hands off the steering wheel. Tramlining is less prominent when you are accellerating, which is why I don't think we are talking about the same thing.

You may need a wheel alignment. If the rear alignment is out it could cause your problem. Other than that, all I can think of is something a little more serious - a faulty rear diff. If the 8 was an older car I might suggest a wheel bearing, but it is too new for that.

Have the dealer check out your rear end (heh, heh...;-)

Update
 

Had the 8 at the dealer's yesterday. Picked it up and the shop manager started talking about 'tire pull'. It sounded like BS to me.

I was just about to tell him I didn't buy a $30,000 sports car that pulls no matter what the reason, when he calls in the head mechanic to confirm the alignment numbers on his printout. The mechanic takes a look and says that even though the numbers are within spec, the spec is too broad and that they can do better than that.

Well, by this time, the wife has started on her way home in the car. So we decide they will adjust the alignment to tighter numbers when I bring it in next week for the other warranty covered replacement parts that are on order.

FYI: the other parts are; 1. The inside weather stripping at both front windows is deformed and curling downward into the door. 2. The AC temp control knob broke off probably by some goon who cracked it while test driving the car.

Hopefully, I'll post a much more pleasant update next week.

Again, thanks for all the fantastic knowledge you guys are passing around. Take care and happy holidays.

2 things would cause pulling during acceleration. Either the thrust lines of the 2 rear wheels are unequal or one wheel is developing more travel per revolution than the other. The first should be taken care of with the alignment. The second one can be caused by diameter differences.

Check both rear tires and make sure they are EXACTLY the same brand, model, width and height (numbers on the sidewall). Seriously. This happened to me once after a repair which involved a wheel replacement. The new tire was 'almost' the same, except the old one was a '65 and the new one was a '70 series (taller profile). I complained about pulling during acceleration, but the dealer kept blowing me off. I finally found the tire discrepency on my own, replaced with another correct size and the problem was gone.

It would seem unlikely that you'd have unequal tires on a new car, but who knows? Maybe there was shipping damage and now you have a Bridgestone on one side and Dunlop on the other? Or different profile of the same tire. Worth taking a look. Even if they are exactly the same, check the tread depth.

If all this fails and you're still having pulling then I guess I'd start suspecting the differential or some freaky behavior by the traction control system.

BINGO! Though they are the same size, the left rear is a Dunlop and all others are Bridgestone! Thanks, Nubo! Happy holidays.

My God this forum kicks ass, doesn't it?!!
Change that tire and let us know the results...! :D :D

this is going into the faq. the deal with this is that the cars are shipped with higher than spec psi. the dealer is supposed to correct the tire pressure during the pre-delvery inspection, or PDI, before turning the car over to the customer. if you havent filled out your Mazda Survey yet then make sure you ding them for this.

Nubo.....
 

Nubo, I just gotta check in here and say "YOU DA MAN!"

A guy in SanFran can diagnose a steering wheel pull for someone in Texas.....brings a tear to my eye ;)

S

another for the faq. that is true the spec is really wide and a good alignment should be done on all of these cars after purchase. maybe 5k to 10k miles so the suspension has had time to settle.

and the cracked AC knob is a known issue that there is a tsb for.

great work nubo!! :D - and yet another ding on the report card for this dealer!!

Hot Dang! I knew that experience would come in handy one day. Hope that takes care of it.

p.s. Tell 'em to replace the other 3 with Dunlops :D ... just kidding

Yes, this forum kicks serious ass. I've learned a whole lot here, and I'm not finished reading it all yet!

Here's something you guys don't know which, now in hindsight, I should have posted....

The dealer had aftermarket wheels we didn't like on the car. We had them replaced with the stock wheels. The first time the wife washed the car, (hey, it's her car :rolleyes: ), she noticed the left rear wheel was curb scratched. I KNEW it was not by either one of us.

So, it went in to get that exchanged. That's apparently when they put the wheel with the wrong tire on the car. Absolutely stupid mistake by the shop, eh?

Did we notice the pull at the time? Sort of, but wasn't sure at first because we were driving it easy for the first 600 miles.

Anyway, I have purposely held off from filling out the survey until all warranty items are taken care of. :D

I'm now studying the SB's!

I will report back on the results of the tire change. Thanks again, folks!