Wheel Allingments?

[Anquetil]

A simple question, are there different types of wheel allignments?

Would a so called suspension specialist have equipment that say Bob Jane would have, or do some places have better allignment machines than others and how do they actually work?

[MegaGTS4]

There are a few different wheel alignment machines out there the most common is the string type, the most accurate is the laser type and there is some ancient ones that rely on fixed head's that attach to the wheel from the hoist/ramp with dial guages and spirit levels.

I have been using the string type for about five years, have done thousands of alignments and they only need to be calibrated every few months with hardly and calibration needed.

The tires wear fine, though it doesn't do the side slip or thrust angle alignment it only does Camber, Castor, toe and SAI and you can do four wheel alignments with it too. First the vehicle is driven up onto a hoist or ramps that have swivel plates that sit under the front/rear wheels these allow for the wheels to be adjusted without the tires creating any resistance on the adjustments, then clamps are clamped to the wheel, some clamps need to have run-outs performed which require the wheel to be raised off the ramp and rotated and the machine checks for inaccuracies such as buckles or flat spots on the rim, others just clamp on and don't Require run-outs to be performed these are called quick clamps,then the heads are attached to the clamps,and they are leveled with spirit levels on them, careful that these aren't bumped otherwise calibration needs to be performed as they have sensitive sensors inside, then there are strings that are attached between the heads, there can be two heads or four, for a four wheel alignment there needs to be four heads otherwise the vehicle needs to be turned around and the steering wheel straighted and the clamps and heads to be set up on the rear after the front has been aligned, the machine is then turned on and the wheel size is entered into it, camber and toe is what they call live adjustments and just need the machine to be turned on to get the readings and adjustments can be monitored in real time, Castor is different requiring the steering wheel to be turned 20 degrees in each direction to get the readings and the readings aren't live meaning that after adjustments are made then the Castor sweep needs to be performed again to check readings.

The laser aligners have four heads that attach to each wheel but instead of strings that can be affected by wind they use the lasers, all adjustments are live ones and they are the most accurate of all the alignment machines, they can also measure the thrust angle, but can't measure the side slip, side slip is usually measured on a side slip meter, this looks like plates on the ground and the vehicle is driven over the top and the side slip is measured in a meter/kilometer reading, if you get a reading like 12m/km means that every kilometer the car travels the wheel would have moved sideways 12 meters if it was allowed to move freely, this is usually determined by the amount of toe in/out that the wheels have, these machine also give a instant toe reading as well, as these machines are a drive over machine you sometimes see them out the front of the service stations, some of these side slip meters also measure brake drag as well as brake efficiency.

If you want to know about Castor, Camber, Toe, SAI, Thrust angle, Scrub radius, Included Angle and set back then check out this site.

http://www.familycar.com/alignment.htm

MEGA

[ferni]

there is also a place i went to that had a computer alignment, stick your car on rollers, and the computer rolls your wheels figuring out what the camber/castor/toe is etc...

[MegaGTS4]

there is also a place i went to that had a computer alignment, stick your car on rollers, and the computer rolls your wheels figuring out what the camber/castor/toe is etc...

Yes but these aren't as accurate as the laser or the string type, and like the side-slip meters should only be used as a pre-wheel alignment to check to see if there is a need for a wheel alignment, as they are basically a big diagnostic tool.

They do not take into account inaccuacys in the tires such as flat spots and uneven tyre wear aswell as buckles in the wheels.

MEGA

[ferni]

yeah i was thiniking that, they said it was all that because it took readings with your wheel turning etc... and the other laser/string type aren't as good...

but pfft

[MegaGTS4]

yeah i was thiniking that, they said it was all that because it took readings with your wheel turning etc... and the other laser/string type aren't as good...

but pfft

Sorry Ferni, actually they do take into account the buckles in the rims but not the inconsistencies in the tires.

All vehicles over a certain age or mileage should have some sort of suspension/front end check for excessive play in joints and wheel bearings before a wheel alignment is performed.

Any joint with excessive play should be replaced other wise the wheel alignment won't be as accurate and even after the alignment may wear tires prematurely, cause bad fuel economy/performance on the road and tire the driver if they have to fight the pulling effect caused by a bad alignment, not to mention the safety factor.

MEGA

[Anquetil]

Great info, thanks for the in depth reply MegaGTS4.

[ferni]

Yeah I wasn't disagreeing with you, just repeating what i was told... wasn't sure weather to belive them or not, you sound like you know what you're talking about

[Anquetil]

Since I've had 265's put on the rear It seems as though I have some 'Toe in' on the rear, is this a normal thing for lowered 33's?

I also get steering vibrations above 115, but only had an allignment 4 weeks ago. So I am wondering whether some of my suspension bits are getting a bit long in the tooth?

[knore]

I have 255s on the back and i can sit at 180 with no vibration at all, i do have a heap of whiteline stuff on the car tho.. camber kit, sway bars, strut brace etc

[MegaGTS4]

Since I've had 265's put on the rear It seems as though I have some 'Toe in' on the rear, is this a normal thing for lowered 33's?  

 

I also get steering vibrations above 115, but only had an allignment 4 weeks ago. So I am wondering whether some of my suspension bits are getting a bit long in the tooth?

Shane, your vibrations have more to do with the wheel balance than the wheel alignment, the only ones that I have seen that suffer from vibrations at 100k's from a wheel alignment is the nissan patrol and landcruiser four-wheel drives, as they tend to suffer from a lack of castor though these need special bushes fitted to twist the front diff to achieve this.

Get your wheels computer balanced as this is relatively cheap at tyre shops and most probably fix your problem.

and yes usually if you lower the ride height on a car with independent rear suspension then the wheels will toe in and camber will increase into the negative, the toe can be adjusted just with a wheel alignment but the camber needs adjustable upper arms to be fitted to the skylines because the factory didn't fit them from standard.

Lowered cars without adjusters tend to wear the inside of the tyres on the rear, sometimes they tend to give it a bit more toe in to counteract this and even the tyre wear out, as toe in will wear the outside of the tyre, but this isn't the best way as your car should have a max of 2mm toe in on the rear.

MEGA

[Sydneykid]

Mega is pretty much spot on, except that you can also buy offset bushes to fix the camber problem. You don't have to buy a complete adjustable arms, plus the bushes cost less. Adjustable arms also usually have spherical joints which are not a good idea on a road car as they wear fast and rattle lots.

Hope that helps