Gm Global Technolgoy Operations, Inc.

Darrin S Mallard

Scott R Kloess

Jose M Lopez

Robert S Brines

Charles J Lemont, Jr

David C Pomerville

William C Gregory

Marc J Tahnoose

Charu S Hayes

Terry R Peterson

A method of determining steering rack rattle propensity of a rack and pinion steering assembly may comprise: simultaneously recording audio, and measuring acceleration of a rack, and right and left side tie-rod end loads; identifying rack rattle events from the audio recording; determining common characteristics of the measured rack acceleration and tie-rod end loads during the identified rack rattle events; creating a rack rattle index level; applying a predetermined force profile to a test rack and pinion steering assembly; measuring a test acceleration on the test rack and pinion steering assembly; calculating a test RMS level in a test frequency range using a test time constant; determining a rack rattle index value from the calculated test RMS level; and comparing the rack rattle index value to the rack rattle index level.

Test procedure for determining steering rack rattle

A wear compensator for use in a vehicle rack and pinion steering assembly and a method of biasing a rack against a pinion shaft gear in a rack and pinion steering assembly are disclosed. The wear compensator may include a rack follower, an adjuster plug, a wear cam and a torsion spring. The rack follower slides on the rack. The adjuster plug is retained by the steering gear housing and includes a plug cam surface. The wear cam includes a wear cam surface operatively engaging the plug cam surface, is mounted between the rack follower and the adjuster plug, and can rotate relative to the adjuster plug. The torsion spring connects between the adjuster plug and the wear cam in order to rotatably bias the wear cam relative to the adjuster plug.

Steering rack wear compensator

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Oxford, MI, United States of America

Darrin S Mallard