Sequential Alignment Fault Diagnostics

[wheels-inmotion]

I wrote a check list some years ago for a national fast-fit chain, it was adopted as an s.o.p but i bet few really used it.

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Sequential Alignment Fault Diagnostics

Condition:

Premature tyre wear

Possible cause:

Incorrect tyre inflation

Wheel alignment out of tolerance

Suspension components worn

Incorrect ride height (1)

Distorted wheel

Incorrect torsion bar adjustment

Loose or worn wheel bearings

Worn shock absorbers

Tyres out of balance

Pulls to one side

Possible cause:

Incorrect tyre inflation

Brakes binding (2)

Mismatched tyres (3)

Broken coil spring (1)

Power steering valve not centred (4)

Wheel alignment out of tolerance (5)

Defective wheel bearings (6)

Damaged anti roll bar drop links

Incorrect castor angle (7)

Wear on nsf tyre (8)

Heavy steering

Possible cause:

Drag link seized

Ball joint seized

Steering linkage seized (9)

Power steering fluid low (10)

Power steering belt loose

Power steering pump defective (11)

Incorrect wheel alignment (12)

Damaged steering rack

Damaged suspension components (13)

Vehicle wandering

Possible cause:

Worn or damaged suspension

Worn track control arm or tie rod (14)

Loose or worn wheel bearings (6)

Incorrect tyre inflation

Anti-roll bar drop link defective

Wheel alignment out of tolerance (5)

Broken coil or sagging coil spring (1)

Method of Testing

(1) Measure ride height from mid wheel arch to the centre of the hub, except no more than 10 mm difference across any given axle, a broken or sagging coil spring can cause a pull even from the rear

(2) If checking when cold, look for hot spots or blued discs,

(3) Rotational/ directional/ asymmetrical/ mismatch bias,

(4) Check track rod threads are even, ignore the position of the steering wheel, may prove steering wheel has been re-set,

(5) Will need to be in excess of 1 degree/ 6 mm normally negative/ toe out,

(6) Worn tapered rear wheel bearings will change the camber angle and cause a pull/ front wheel bearings are harder to test cold/ hold the coil spring and spin the wheel, if you feel a rumble then the bearing is worn,

(7) In most cases will only go wrong by an impact, tell tale sign, the wheel alignment will be a long way out, if a full wheel geometry is not available, check to see if the wheels have excessive set back, measure mid-wheel to mid-wheel, front to rear, ns and os, if the lowest is the direction the vehicle is pulling,then the castor is probably wrong, avoid setting just the wheel alignment as this will not resolve the pull and probably generate a complaint,

(8) Due to the road layout (UK) the nsf tyre has a smaller turning radius than the osf, this will cause the outside of the nsf tyre to wear more than the osf, this pattern of wear is unavoidable, if the vehicle is pulling left and the nsf is showing signs of wear, move the front wheels side to side, or front to rear, then test and adjust wheel alignment, non compliance is a common reason for an after adjustment complaint,

(9) Common on Fiesta/ Escorts, jack up front wheels and turn steering, if (terminology differs) the steering column/ linkage/ coupling/ joint, is seized it will go tight 180 degrees, � turn,

(10) The more the steering is turned, the more the pump will scream,

(11) Jack up front wheels, start engine and rev to about 2500 rpm observe if the steering wheel moves, also manually check the steering's resistance by moving the steering wheel from left to right,

(12) Will need to be in excess of 1 degree/ 6 mm positive/ toe in,

(13) Disconnect track rod from strut, turn strut from side to side, and feel if metalastic bush Is seized----

(14) If front wheel drive the wander will deviate left/ right under acceleration/ deceleration, beware a worn engine mount on a front wheel drive vehicle can also cause this, by off setting the drive shafts, rear wheel drive will deviate mainly under braking, or coming of bumps,

[JezvRS]

Perfect this is just what I need! A thousand thank you's! Could any one confirm whether this also addresses some balancing issues i.e. shaky steering at certain speeds?

Edited 13 April, 2010 by JezvRS

[notts-vrs]

ive had my car in at skoda more times than ive had hot dinners over tracking issues and pulling to the left.... answer I get every time, nothing found to be at fault.