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Words and photos by Wayne Scraba

hocks and suspension issues in racecars is a pretty common thread, but one thing some folks neglect is this:  The need to remove "stiction" from suspension components.  Basically, in my own personal application, I quickly discovered that certain aftermarket bushings create a considerable amount of sticking and friction in the suspension (hence the term high end shock absorber manufacturers refer to as "stiction").

OEM control arm bushings are designed to live a long life and for the most part, to be easily serviced in the field.  They're a compromise between ride, handling and cost.  There are plenty of bushings options out there, including custom made spherical bearings, non-serrated OE-style bushings, urethane bushings and in the case of this article, "Del-A-Lum" bushings.  We’ve tried most of these pieces, and at least from this writer’s perspective, the Del-A-Lum bushing system likely offers the best results compared to the effort required for installation.

To recap, when the suspension system in a racecar has this stiction, it means the shock can't do its job effectively.  In reality, the bushings I used were sticking (due to friction) during suspension travel.  This also meant that as the bushing heated up or cooled down, the amount and rate of travel available in the front suspension changed, often by dramatic margins.  Additionally, it meant that the shock absorber settings could never be the same from one trip down the quarter mile to another.  In simple terms, the bushings were doing much of the job the shock was supposed to handle, but without any consistency or any adjustability.  A solution was arranged to resolve this matter.  Without going into detail, a special sleeve was fabricated to take the place of the OEM bushing sleeve in the control arm.  From that point, a high strength spherical bearing could be used to replace the bushing.  The upper bushings were effectively loosened by lightly honing the ID (you also have to keep in mind that the torque required on the fasteners which hold the components in place does not change -- only the torque required to move the suspension system changes).  What I ended up with was a break away torque of less than 5 foot pounds, without a spring or shock mounted in the front suspension system.  The idea worked.  The suspension was now one loose puppy.

This is a basic Del-A-Lum bushing, broken down.  Basically, the bushing consists of an aluminum bushing housing.  Inside is a Del-A-Lum insert.  On either end of the bushing housing, a large diameter Del-A-Lum washer is installed, sandwiched with another large diameter steel washer.  As you can see, the system includes a grease fitting, and by design, each piece can be serviced.


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