Magnum 500 Center Cap Lock
By Rick Maginnis
To help secure and prevent theft of Magnum 500 center caps, a simple 60 cent retaining
ring may be installed using snap ring pliers.
Figure 1 shows the components involved. In this example, a center
cap for the small 2 inch hole Magnum 500 is shown. The relaxed diameter of the internal
retaining ring is approximately 2.1 inches as illustrated in figure 2. After the wheel is
removed from the car, the retaining ring is compressed with the pliers as shown in figure
3 and placed into the back side of the center cap. When installed (figure 4) the retaining
ring expands causing the center cap's metal holding clips to firmly grip the outer edge of
the hole. Voila! The center cap will not rattle or come off while driving and is darn near
impossible to remove without first taking the wheel off the car - cheap security!
The 1-15/16" steel internal retaining rings used in this
example were obtained online from Barnhill Bolt Co.,
Inc., Albuquerque, New Mexico. Part no. #N1300-193 at a cost of 0.62 each. (shipping
was twice the cost of the parts.) Another near optimal ring would be the slightly smaller
1-7/8" part #1300-187. Evidently, there is considerable variation in hole diameter
from one wheel to the next. The smaller size was experimented with first and fit well on
one spare Magnum 500 wheel but didn't provide as much gripping force on four other wheels,
hence the use of the slightly larger 1-15/16 ring. Buy both - mix and match as required.
For 2-1/8" hole diameter Magnum's a larger retaining ring will be necessary.