When you're diagnosing a vehicle that leads or pulls, have you considered the effect of road slope? Road slope is a major contributor to vehicle lead/pull complaints.
As a part of normal operation, vehicles will follow side-to-side road slope or road crown. So, first check with the customer about the types of roads they are driving on. Some drivers do not recognize the influence of road slope on vehicle pull/lead.
Roads typically have some degree of crown or slope to allow for rain run-off. Vehicles are designed to compensate for a slight amount of road crown, but evaluating a vehicle on the wrong roads can lead to improper diagnosis.
For example, if you are testing the vehicle for a "leads to the left" concern, you will want to evaluate the concern in the left lane as well as in the other lanes. If the vehicle quickly climbs the road crown, then it may have an issue that needs to be looked into further.
So, be sure to understand the customer's operating environment and whether or not road slope is causing the customer's concern (fig. 17).Â
RED ARROW: Cause -- road slope pulls vehicle
GREEN ARROW: Effect -- driver pulls at steering wheel.
TIP:Â Do your test drive on actual roads, not in a parking lot, to give you a real world impression of the vehicle's behavior in right and left sloping lanes.
For further assistance please reference the leads/pulls diagnosis document in SI.
- Thanks to Brian Snyder and Dan Stress
As a part of normal operation, vehicles will follow side-to-side road slope or road crown. So, first check with the customer about the types of roads they are driving on. Some drivers do not recognize the influence of road slope on vehicle pull/lead.
Roads typically have some degree of crown or slope to allow for rain run-off. Vehicles are designed to compensate for a slight amount of road crown, but evaluating a vehicle on the wrong roads can lead to improper diagnosis.
For example, if you are testing the vehicle for a "leads to the left" concern, you will want to evaluate the concern in the left lane as well as in the other lanes. If the vehicle quickly climbs the road crown, then it may have an issue that needs to be looked into further.
So, be sure to understand the customer's operating environment and whether or not road slope is causing the customer's concern (fig. 17).Â
RED ARROW: Cause -- road slope pulls vehicle
GREEN ARROW: Effect -- driver pulls at steering wheel.
TIP:Â Do your test drive on actual roads, not in a parking lot, to give you a real world impression of the vehicle's behavior in right and left sloping lanes.
For further assistance please reference the leads/pulls diagnosis document in SI.
- Thanks to Brian Snyder and Dan Stress
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