No matter how bad it looks, it’s seldom the transmission’s fault.
Photo 1: Impact-damaged spur gear displays brittle, granular texture typical of sudden breakage.
Photo 2: Fresh shock damage is evident in a Southeastern Freight Lines’ transmission.
Photo 3: Forcing or “grinding” gears usually leaves partially damaged teeth that appear polished and shiny.
Photo 4: Gear-tooth spalling is relatively benign, and could have been caused by poor lubrication or excessive loading.
Photo 5: Bearing discoloration and scoring is likely the result of low lube.
Photo 6: Complete burn-up, probably caused by low or no lube, shows catastrophic degeneration with telltale “apple coring.”
