LeighJ

Is is grand name for wheel balance ?? if not do you know what's invloved.


Cheers,

UkLegacyT

what do you mean, sorry - i dont understand the question?
ian

LeighJ

I had my Scooby serviced this weekend, and I need to take it back in a few weeks for a geometry check, what Iam trying to establish is, what is this check, whats involved.

UkLegacyT

this check is the geometry/alignment of the wheels, more commonly known as 'tracking' or 'wheel alignment'.
on 90% of cars, only the front wheels are adjustable.
the wheel alignment is basically the toe in/out of the front wheels. subaru's (impreza & legacy) correct setting is 0 degrees (i.e. - running perfectly parallel, no toe in or out) although they can be set at -1 degrees (toeing out 1 degree, to help combat torque steer of modified cars.
if the alignment is incorrect (caused by general wear or knocking a kerb etc), it will cause uneven wear of the front tyres. If toeing out, the inside shoulder of each tyre will wear at a faster rate than the remainder. Likewise, if toeing in, the outside shoulder of each tyre will wear faster.
During the service, they have probably just noticed a bit of wear/scrubbing, and hence suggested the check as reasurance.
If the alignment is incorrect, the shoulder (either inner or outer, depending on whether toeing out/in) will wear to a bald strip around the circumference of the tyre. The tyre is then illegal.
also note that a slight scrubbing of the outer shoulders can be caused by fast/hard cornering. also, cars with power steering wear both inner and outer shoulders at a faster than normal rate, especilly in the steering is turned often while stationary.
if you have one front tyre with outer wear, and the other front tyre with inner wear, this is a cause for concern, and may be due to incorrect camber.
hope this explains
regards
ian

LeighJ

Thanks very much for that Ian.

Leigh

UkLegacyT

your welcome mate

ian

Dave T-S

Not being pernickety, but to answer the question a full geometry check/alignment is not just checking the tracking.

It is:
Toe (relationship of the opposite wheels to each other on the same axle, in a parallel measurement).

Camber (measurement of the wheel in relation to the vertical plane i.e. how much the top of the wheel leans in or out, in relation to the bottom).

And lastly caster (or king pin inclination - the relationship of the wheel axis fore and aft to it's top and bottom swivel points).

A proper full alignment check will, or should, address all of these on an Impreza, both front and rear (and in relation to each other).

[Edited by Dave T-S - 1/14/2002 2:42:38 PM]

LeighJ

More thanks required, gald I'm not doing it, sounds like a right pain in the..