 The replacement of the original standard transmissions eliminated the trademark "jamming" sound.However, the well-intentioned modifications in 1989 added stresses to the frame; during the summer 1999 season, one of the Red Jammers lost a front axle after the increased stresses had cracked the front frame members, and closer inspection revealed cracks in many buses, forcing the park's concessionaire to retire the fleet immediately.By that year, it was estimated that each bus had operated for at least , assuming of operation each day for 60 years of 100-day seasons.