car steers left after alignment.

[_R_J_K_]

How the value doubles is, the greater value is on the right, when it should be on the left....So currently we have a .15 difference between left and right....The left value should be at least .15 greater than the right.....So add .15 onto the left value brings it equal to the right....Then add the .15 that it should be of a greater value, which then brings it upto .30, which is double the original figure you originally quoted....

Semantics of wheel aligning really. I get that .15 on the left is a good all round number for the masses, but as somebody who aligns their own caster equal I wouldn't exactly say that makes it 0.3 out given how much road slope varies, and likely not enough to cause this issue.

 

[RevNev]

shouldnt the GDS have picked up a bad centre? wondering how holden got it so wrong (other than competency). if they are the only ones that can test centre am i screwed? destined to live my future in a holden workshop

If the centre has been altered from a previous GDS reset, I'd think it should show a scan fault, but I've never tried it to see if it does.

 

[RevNev]

yeah it is certainly pulling strongly. i have had drift on cars before but this is literally like turning the wheel about half as much as you would to lane change on a freeway.

Something else you can try is swapping the front wheels left to right. I wouldn't expect a Bridgestone tyre to cause a drift but sometimes, there's an odd tyre fitted to the front will cause the car to drift. Put it back on the front again in a rotation, the car will drift again.

Having said that, we've got an FGX Falcon ute that drifted left after RE003's fitted, no wheel alignment and didn't drift with the old Dunlop's. That was a castor issue with 1.5 degrees less caster on the LHF than the RHF but interestingly, the new RE003's emphasised the castor issue.

I've got 245/45 x 18 RE003's on my VF2 SV6 ute (stock wheels), 0.5 degs camber and 1mm toe in with a GDS stop and centre reset and drives straight depending on heavy road camber it can drift a touch to the left or right as most cars will. Castor I didn't check having 44,000km's no crashes or even a kerb rub and isn't adjustable.

 

[vc commodore]

Semantics of wheel aligning really. I get that .15 on the left is a good all round number for the masses, but as somebody who aligns their own caster equal I wouldn't exactly say that makes it 0.3 out given how much road slope varies, and likely not enough to cause this issue.

You'll be surprised what a minute difference can cause.....And honestly, neither of us know how much slope the roads have around the OP's area to make a determination whether that minute difference is the actual cause...

I can take a 5 minute run from my house to a 3 lane road and depending on which lane I drive in, depends whether the car drives straight or whether I have to hold the steering wheel slightly right to keep the car driving in a straight line

With that being said, from what I read of the alignment report, it's either the caster causing the problem or tyres (which I first mentioned)......Would be interested to see what the actual issue is

 

[Skylarking]

A vehicle always drifts to the side with the least caster.

Don’t know what’s done with our modern cars but in older cars I thought caster was usually set positive 1/4 degree more on the passenger side than the drivers side to cater for road crown. The larger the caster difference, the higher the force that pull the car to the side with less caster.

Making the passenger side 0.25 degree more will compensate for a crowned road but it’s a balancing act as one tries to equal the left drift induced by the road crown itself with a right drift induced by the lesser driver side caster. You could get a car to steer straight on some crowned roads but then you’d have unbalanced forces on flat freeways that result in a pull to the right So cars used to be aligned for the roads one travelled on, using string, older alignment machines and operator knowledge and such old school methods. And this was at a time when power steering was a luxury so caster was very positive to induce steering self centring forces.

But newer cars have wider and lower aspect ratios tyres and power steering which must impact the caster induced forces somewhat…

It’s all interesting subject matter but in this case, as mentioned, it’s likely an issue with the electric power assistance and the lack of calibrating the electronic system to recognise the actual physical steering centre position after the alignment. Doubt the EPS system is capable of determining whether the calibrated centre and the actual physical centre position are in agreement. Such is probably why the EPS system pulls the steering to the calibrated centre which obviously causes the vehicle to steer (because of the calibration error)… Either that or one of the new front tyres are faulty…

 

[C0000005]

They changed tires front/back and also left/right with no change.

 

[RevNev]

They changed tires front/back and also left/right with no change.

Have you had the car on another wheel alignment machine to confirm the printout is in fact correct. The car could be rear wheel steering causing the drift to the left if the rear toe isn't centred and biased to the right. It's the reason I personally string line with manual measurements to eliminate machine error albeit, string lining isn't practical for most suspension or alignment/tyre shops.

 

[C0000005]

Have you had the car on another wheel alignment machine to confirm the printout is in fact correct. The car could be rear wheel steering causing the drift to the left if the rear toe isn't centred and biased to the right. It's the reason I personally string line with manual measurements to eliminate machine error albeit, string lining isn't practical for most suspension or alignment/tyre shops.

it was also done at trax and holden but i dont have the results.