Thread: Wheel alignments - a word of warning.

Originally Posted by isuzurover

Yes, you really need laser alignment to get between 1.2 to 2.4 mm...

On all solid axle vehicles someone with a string line and a couple of spanners can do as good a job as the best laser...

I used to do that back in the old days and get a better result than paying for a wheel alignment.

According to RAVE, the front alignment is Toe-out 0.8mm-1.5mm or more accurately, 0deg5' to 0deg 15'.

With all respect to eagle eyed aligners with string and chalk lines, I defy you to meet the precision required above when thin string itself is at least 0.5mm thick and the chalk line even thicker... if you add up the order of accuracy given the minimum widths of these "measuring instruments", then you may well calculate the result as say 0.5mm but it probably has a +/- 3mm error.If you are using a metal tape measure for example then you also need to take into account the thickness of the markings on the tape and parallax error.

The benefit of using a simple laser setup is that by projecting the beam some distance from the vehicle, a small displacement of the steering can be magnified many times. So a 2cm adjustment of the beam position for example can reflect a 0 deg 5' movement of the wheel. So if the limit of reading of the position of the beam is +/- 1mm then this corresponds to a steering change of just +/- 0.25' ! Far more precise and accurate than a string and chalk...
Now in the scheme of things, talking into account worn bushings etc, it may not matter a damn if the toe in/out is +/- 3mm from that specified... but that doesn't detract from the fact that a string and chalk are inherently less precise and accurate than a properly set up laser ...

Originally Posted by Hoges

According to RAVE, the front alignment is Toe-out 0.8mm-1.5mm or more accurately, 0deg5' to 0deg 15'.

With all respect to eagle eyed aligners with string and chalk lines, I defy you to meet the precision required above when thin string itself is at least 0.5mm thick and the chalk line even thicker... ...

Challenge accepted....

Originally Posted by isuzurover

Yes, you really need laser alignment to get between 1.2 to 2.4 mm...

On all solid axle vehicles someone with a string line and a couple of spanners can do as good a job as the best laser...

Yep, and as I've mentioned numerous times in the past, guess how race cars are wheel aligned?

Hint, there's nary a laser aligner to be seen.......

Lasers are used in a shop setting for ease of setup and consistency, a string line can be just as accurate but you need to pay attention to its setup.

Soooooo where does everybody take there measurements from.........I use the out most part of the rim on a 16" rim ie where the lead weight sits

Is this the right spot??

Oh it's been years since I have done it..........that last time was when I got a new set of front tyres and the tyre shop did it

I don't think our Rangies are high-performance, precision-built machines needing quite that level of accuracy. I say because: a) I'm not driving 400kms to the nearest alignment shop; b) I've done it myself for the last couple of decades with two rulers and had no trouble; and c) just recently I fixed a problem with the rear axle where someone had put the front bush of one trailing arm with the triangular plate of the bush ahead of the chassis mount, not behind. So the rear axle had been crooked for years, and it made no difference to the tyres, or steering, or anything really. There's a lot of leeway with these cars.

Originally Posted by weeds

Soooooo where does everybody take there measurements from.........I use the out most part of the rim on a 16" rim ie where the lead weight sits

Is this the right spot??

Oh it's been years since I have done it..........that last time was when I got a new set of front tyres and the tyre shop did it

its supposed to be at the lip of the rim. I set 1mm toe out via the parallel box method measured at the bead lip on the rim. (where the weight sits, not where it clips on)

if Im measuring at the tread face using the wheel tread (on standard size 7.50r16 tyres) I aim for 2mm toe out but will settle for 1.5-2mm toe out.

When Im feeling the need to be accurate I use a DTI magged onto the rim and spun straightened winding wire or .032 mm tie wire to make the parallels and rely on 3/4/5 to set the square with and use diagonal length cross checks to confirm.

Havent needed to do that since the last time someone bet me a carton I couldnt be more accurate than them using the string line method vs them on the laser.

Originally Posted by superquag

As a wheel alignment techie explained to me way back in the last century...

Rear-wheel drive cars have toe IN, as the rolling resistance/drag from being pushed from the back only, tends to force the front wheels backwards and thus compresses and flexes the suspension components. Nett result is:- front wheels pointing pretty well dead-ahead under speed.

Front-wheel drive cars are set toe-OUT, as the 'pulling' of the front wheels flexes everything so that the wheels try to go forward and leave the car behind, and the end result is... Front wheels point dead-ahead. (More or less....)

All-wheel drive cars such as a D1/2 or Rangie are sort-of somewhere between, and I suspect can be more finicky when setting and more easily influenced by tyres, driving techniques, condition of suspension components -as has been mentioned as Very Important - and the price of Tea in China.

I've heard that rule-of-thumb before too. But it's wrong. Two of my fwd cars have to run toe-in to keep tyre wear consistent and handling good. One incompetent alignment outfit set them both to toe-out. They swam all over the road and chewed out a set of fronts in 15,000km.
The spec on my AWD (fwd with a rear diff that pushes when things get slippery) car is up to 5mm toe-in front and back! Currently set to around 2.5mm front and back.

I run my 85 rangie with 1mm toe-in so it's more predictable going from corner to corner. My 93 I haven't checked, but it's soo damn thirsty it gets driven extra-slow anyway.
The 85 has had exactly 1 wheel alignment (I needed the print-out to confirm an axle tube was bent). I told those clowns to not touch the alignment, when I got it back they said not to worry about the 4mm toe-in at one side on the rear.
They had also "adjusted" my front toe-in to toe-out by bending the front track-rod.

The rangies are now done by me and a helper with a tape. This method is just as accurate as lasers for these vehicles, anyone who tells you otherwise is bull****ting. The only adjustment is front toe.
Unfortunately on my other cars (4 wheel independent) there are adjustments besides front toe (caster and camber on each corner) and it's extremely difficult to find a competent and trustworthy outfit.