Wheel Geometry

tin79

Hi everyone

My girls 03 Hyundai Coupe recently went throught the NCT. All good except for that i forgot to take the alloy centre caps off and the rear wheel alignment.

The rear axle alignment was just out (had to be within + or -18 and it was -19). So she took it to advance pit stop who alligned it and who assured her it was all sorted. on the re-test it failed again with the exact same readings as before.

took it back to advance who claimed it was the fault of the NCT machine (likely story, considering she made the NCTS test it on 3 seperate machines over the 2 tests) and that they could not read any imbalance. we insisted that they allow us to have it checked on a machine in another branch (which made 3 of their branches we were at) and this time an imbalance did show up, which they claimed they resolved.

So back to the NCT and this time it passed, but only just with a reading of -18 and that was because the tester remembered her from the two previous tests and did his best to pass it, having seen the print outs from advance and the effort she went to to get it resolved.

so i guess i have come to what seems to be the common opinion that Advance laser alignment is rubbish, i was considering looking for money back but seeing as it passed eventually i may leave it. I am not happy with it so what should i be looking to get done now?

I am guessing full geometry in blanch maybe? or rear alignment at the main dealer in fairiview?

Thanks for any info

oh also, just on a seperate note i saw diesel for €1,37 in shell Balbriggan today €1,13 in maynooth on sunday

Mr.David

I have been giving out about this for a while now, but I have been alone.

Wheel Alignment is a CON.

Geometry and alignement are seperate issues. Alignment works on major assumptions and accounts for very few of the critical angles that make up the "geometry".

Getting the geometry fully done is another thing altogether and is much much more comprehensive.

Mr.David

Tracking/Alignment
Is linear, this measurement shows no concern for any other angle. This form of measurement is the most common in the World and the most damaging.
Angles measured 1

Four wheel Alignment
Uses the rear wheels as a scale to centre the steering rack.... then the front toe..... this is better but is assuming the rear is centred.
Angles measured 2

Four wheel Laser Alignment
Same as above.... be wise!

Geometry/Primary
Will image the exact rear centre line to permit a centred steering wheel.. additionally the front and rear camber positions will be measured. This is the most common form of Geometry and i consider this as 'basic'
Angles measured 8

Full Geometry/primary and Secondary
Is absolute but harder to understand. Few places even with the equipment measure the Secondary angles, these include...
Castor
KPI/SJI/SAI
Scrub radius
included angle
TOOT/Ackerman
Delta curve
and so on

Most areas that involve rapid tyre wear or handling issues need to be read from the 'Secondary' data, even more important if the car has been modified or for diagnostics after an accident.
Angles measured 15+

MercMad

I think most centres can do tracking and camber and thats it. Even if they did spot something wrong I dont think they would know how to adjust it correctly.

tin79

Thanks for the replies

yeah i saw that while i was searchign there mrDavid. some good info there, cheers

gofaster_s13

Wouldnt let Advance or any of the other tyre places near my car, the people working there in the most cases are NOT mechanics, they are tyre fitters, auto mechanics is a trade for a reason it amazes me the amount of people who leave cars in to those places and wonder why jobs are not being properly done, worst I've seen yet from a certain nationwide tyre franchise was a brake pad installed backwards with the metal backing plate rubbing against the brake disc.

Mr.David

Stories like this one from a UK geometry/wheel fitment centre are all too common::eek::eek::eek:

To fit a 17" tyre on to a 17" wheel takes some doing nowadays since they both have the same diameter so "how do they do it?"

The wheel has a centre diameter lower than the face diameter so during fitting the tyre needs to be off-set in this recess, but modern tyres are very stiff and maintaining this off-set is reasonably skilled.

The example below shows how the fitter failed to maintain an off-set allowing the machines fitting shoe to cut into the tyres support bead line, consequently the tyre did blow out and fortunately no one was hurt.

Here is the cut tyre bead




And here is the part of the fitting machine that cut into the bead


There is nothing any owner can do to a tyre that could produce this sort of damage.... It can only come from the fitting, "be wise!"

tred

gofaster_s13 wrote: »

Wouldnt let Advance or any of the other tyre places near my car, the people working there in the most cases are NOT mechanics, they are tyre fitters, auto mechanics is a trade for a reason it amazes me the amount of people who leave cars in to those places and wonder why jobs are not being properly done, worst I've seen yet from a certain nationwide tyre franchise was a brake pad installed backwards with the metal backing plate rubbing against the brake disc.

can we set up some sort of post , recommending people who are good at say Full Wheel Geomtery, or allignment?. I payed someone cash a few years ago on laser allignment, and id swear it was worse afterwards.

I need to get the gemotery dont on my mondeo, and right now, i have only
got a recommendation for someone in blanchardstown that can do it.

Mr.David

I agree, its so common for people to get caught out with this nowadays. I cannot help though as I live in the UK now and know only of places over here that do it.

A quick check though - ring them and ask them do they use a Hunter machine to do the geometry. If they do its proper, if not its not!:D

gofaster_s13

Mr.David wrote: »

I agree, its so common for people to get caught out with this nowadays. I cannot help though as I live in the UK now and know only of places over here that do it.

A quick check though - ring them and ask them do they use a Hunter machine to do the geometry. If they do its proper, if not its not!:D

Some of the fast fit places use the hunter gear but its only as good as the person using it, if he doesnt know how to use the machine he might as well be using a measuring tape.

gofaster_s13

tred wrote: »

can we set up some sort of post , recommending people who are good at say Full Wheel Geomtery, or allignment?. I payed someone cash a few years ago on laser allignment, and id swear it was worse afterwards.

I need to get the gemotery dont on my mondeo, and right now, i have only
got a recommendation for someone in blanchardstown that can do it.

Generally crash repair centres(if they have the gear) are the best people to do a full laser alignment as theyre dealing with insurance claims, independant assessors etc.

dohc

So any places that you can recommend

mickdw

Just for people with modern audi/vw, I believe there is also a raised toe check which needs to be carried out as the complex suspension setup can be set up perfectly when car is sitting on its wheels however suspension movement can cause major bump steer if this raised toe is not checked/correct. There is a dealer tool too to set the suspension at the correct raised height so really dont let any independant near these cars. This raised toe check might not be so critical for every alignment but certainly after replacing suspension parts or crash damage it would have to be done

ismynametoolong

OP Wheel alignment is not checked on the NCT . What is checked is shock absorber performance or inbalance and side slip ie sideways movement of the wheel on a slip plate. You need to bring you car to a competent technican or garage and not advance who use € 20K worth of equipment operated by a 16 yr old or unqualified individual.
If you want a car set up right on four wheel alignment go to somebody with a laser alignment system not a computerised system. The tolerance parameters in the computerised systems are too big and once the operator gets a green lights per wheel they think the alignment is set. Front camber where adjustable is one of the most important settings and I have never seen a fast fit place adjust this ( I dont think they would know how) .

tin79

Thanks for that ismynametoolong. I might try Dave Mc Cann tyres in D15, seems reputable.

Cheers for all the replies

dohc

Im not so sure thats wise,Lets just say i heard bad things about that place.I need my car done as after getting tracking rods done.
I would like to know a good place

gofaster_s13

ismynametoolong wrote: »

OP Wheel alignment is not checked on the NCT . What is checked is shock absorber performance or inbalance and side slip ie sideways movement of the wheel on a slip plate. You need to bring you car to a competent technican or garage and not advance who use € 20K worth of equipment operated by a 16 yr old or unqualified individual.
If you want a car set up right on four wheel alignment go to somebody with a laser alignment system not a computerised system. The tolerance parameters in the computerised systems are too big and once the operator gets a green lights per wheel they think the alignment is set. Front camber where adjustable is one of the most important settings and I have never seen a fast fit place adjust this ( I dont think they would know how) .

Side slip is the tracking measurement if you look at the measurements on the NCT fail sheet, side slip is measured in metres per kilometre(M/KM) sideways wheel movement is visually checked on the shaker plates on the front of the NCT ramp. Camber settings are no more or less important than any other geometry setting.

Jonty

corcoran's in Portlaoise do a full geometry. I know its too far!

ismynametoolong

gofaster_s13 wrote: »

Side slip is the tracking measurement if you look at the measurements on the NCT fail sheet, side slip is measured in metres per kilometre(M/KM) sideways wheel movement is visually checked on the shaker plates on the front of the NCT ramp. Camber settings are no more or less important than any other geometry setting.

If the car has failed because of side slip then no amount of wheel alignment will fix it it is caused by wear in a bush of movement in the suspension and should be inspected by a competent person and not the likes of Advance. If the front camber is not set correctly during four wheel alignment then the four wheel alignment is not set correctly and the handling / tyre wear will be adversely affected

tin79

well it failed on "rear axle aligment", the imbalance was -19m/km. is that likely to be simply fixed by full geometry or would it be more likely to be caused by a worn part? something that would need replacement?

gofaster_s13

The side slip tester measures toe in/toe out(commonly called tracking) in your steering geometry/wheel alignment which can be caused by worn bushes or as is more often the case the wheel alignment/geometry needs adjusting/checking.

tin79

thanks for that, will get the geo done and will get a check on the bushes too.

tred

tin79 wrote: »

thanks for that, will get the geo done and will get a check on the bushes too.

http://www.fordmondeo.org/forum/showtopic.php?tid/780420/


interesting post on geometry..