A Real-Life Example of Why Materials Quality Is Important

Last Summer, I replaced both of the front stabilizer links in my pickup truck. At that time, the rubber bushings were disintegrating. One of the links had actually broken due to hitting a particularly large pothole. I thought, barring another large pothole, this would be the last time I'd be dealing with that for at least a couple years. Alas, that was not the case.

A couple days ago, I was driving and heard a clunk, followed by some pinging noises. Upon looking in the rear-view mirror, I noticed a rod-shaped item bouncing in the roadway and thought I must have driven over some trash in the road. A few minutes later, I heard more noises and saw more objects rolling around in the road behind me. I also noticed the handling was suddenly really "loose". Then I realized these were coming off my truck and were NOT stuff already in the road. I pulled off at the nearest gas station and, upon peering under my vehicle, found the situation shown in the stitched photo of both the left and right front suspension. Note the missing parts in the right-hand side of the picture v.s. the left. Fortunately the part that broke was NOT a life-or-death critical component - but this was unnerving nonetheless. Also extremely annoying is the fact I had replaced these parts less than 7,000 miles/6 months ago - and certainly did NOT plan on doing this in 15 degree weather.

While I bought these parts at a legitimate auto parts store, my guess is there was a flaw in the metal - perhaps a void - that created a weak spot which just happened to fail at that time.

The following day, I showed these pictures in class to my Applied Engineering students as an object lesson in why manufacturing quality is important and the possible real-life consequences of product failures. Judging from their reactions, I think the point was made and got across to one and all.