vague steering problems

[murrayarnold]

Hi guys
I fitted 205/60/13 advan AO48 yokohamas to my spider, front and back, on 8" rims. On the back I have wheel spacers and same on the front. Like 5mm I think.
All steering and suspension parts are new, including steering box. yet the car will not track true. It's as if it keeps getting the tyres caught in ruts in the road and will wonder left or right when it suits it.
I Think that maybe the front tyres are to wide

Does anyone have any similar knowledge of this problem.

Thanks guys.

[AriK]

I have the same size tires on less wide rims, no spacers. Handling is great. You need an alignment shop to look at it.
You found 205-13s new? unbelievable

[murrayarnold]

if your in America I have to assume that 13'' tyres are not a common size. I live in Croatia now and I could not get them here. But in Britain they stock 13'' tyre's in every garage. But I used Demon tweeks for mine who will ship.

http://www.demon-tweeks.co.uk/performan ... 048-r-tyre

By the way, this company stock everything.

[murrayarnold]

regarding what looks like a toe in/out issue. I think I will do a trial and error test by first taking it from where it is and start an even adjustment out and then in until I feel its on a neutral and straight tracking. Will let you guys know how it goes.

[RRoller123]

string method works pretty well, too.

First make sure car is level, both front and back:



Then stretch a string around the 4 wheels:



I leave about 1/8" gap at the front of the tire, with the string just barely touching the rear of the tire:



Works surprisingly well!

Pete

[AriK]

Another method is to use a telescopic broom stick and use its adjustable length to measure toe from driver's sidewall to passenger's sidewall in front of the wheel and compare that length to the distance of the sidewalls at the rear of those same wheels.

[vandor]

Pete,

That method would work it the front and real track were the same, but they are not.

The easiest way to measure toe-in is to mark some thread blocks and measure the distance between them.
Then roll the car forward so the marks are toward the rear and measure again. The difference gives you the toe-in. .

[murrayarnold]

ok I kinda understand. So taking the car is pointing straight ahead, I measure the inside distance between the front wheels. The front inside and then the rear inside (of the front wheels)

Ok now having done that, What difference should I be aiming for. Should there be greater reading on the front edge and if so by how much. Obviously I am assuming that both wheels are both pointing ahead with identical geometry. Seeing the cars going left and right I will make that assumption.

So lets say for example the reading is the exact same. but I need there to be 1/2'' greater, than each wheel would need the front end pushed out 1/4''

Do I have the basic grasp of the plan and as I asked, what difference should there be

[azruss]

you want a slight toe-in, so the front will measure shorter than the rear. outside of the tire should have about a 1/16" toe in. If you are measuring at the wheel, then you will be a fat 1/32". The issue here is the car cannot be jacked up as that changes the camber. There isnt enough clearance under the car to get a very high reading on the back.

[murrayarnold]

I just worked that part out regarding measuring it. Looks like the string method is the way to go. Mind you getting under to adjust it with its slightly lowered suspension. Will try this tomorrow and let you guys know the results

[vandor]

Fiat specifies a toe-in of 3mm +-2mm. I am pretty sure this would be measured at the wheels.

[djape1977]

check the condition of your front A-arm bushings, and shock towers.
wider wheels will put more strain on silent blocks, and ones that worked fine with stock tyres might show their true condition when wider wheel are fitted. also, be aware that wheels with significantly smaller offset will inevitably cause bump steer, because the lever acting on front axles is now longer

[RRoller123]

Csaba, I understand your point, but it does work, I have thousands of miles on the tires with no unusual wear pattern at all, and no steering issues. Tracks perfectly doing it with the string method. I can't explain why, but it does work well, and is quick and inexpensive.

[murrayarnold]

Hi guys. Ok, before considering all the issues with wider wheels and tyres.
I set the strings carefully (the wife assisted) glad we aint working on the clutch, for some reason my wife goes through loads of them, hmmm. Anyway, here are some observations.

So I measured the driver side wheel. But first thing is how do I know I have the car pointing straight. Now this is where you can assist.

I decided to turn the steering wheel until I had the exact same measurement on the driver side wheel. This for me means ( in my head) that I will now only need to adjust one wheel. correct?

Now I measured the other side and found the front edge to be 5mm greater, meaning its toeing in. But does this mean both wheels are towing in by 3mm as the track should centre itself. Which in turn means that the tracking is correct as someone mentioned.

Taking that to be correct, that means the next issue, as djape1977 said. So now I will remove all wheel spacers and double check the condition of the bushes. As I agree, the wider the offset (not the wheel) the more strain on the bushes and bearings which will not as easily show up on standard wheels where the centre of the wheel is in line with the hub. Even weight distribution. Off course if I had not thrown out the old wheels, oh I never keep anything I take of a car. Normally skip it. Don't shout, I have 5 cars and if I were to keep everything I would need another garage. And living in Croatia, someone would want the part but the shipping negates this. My bad for living here I guess.

Right, enough chat and out with the jack to do some research. Wish me luck.

[spiderdan]

sretno murrayarnold