ASE H3 Drive Train (Transit Bus) case studies
ASE H3 Drive Train (Transit Bus) · Put your knowledge to work in context.
The ASE H3 Drive Train (Transit Bus) credential is part of the ASE certification series for service professionals who maintain and repair transit buses. It is aimed at technicians working in transit fleets, municipal operations, and shops that service heavy-duty bus drivetrains, and it is one of several tests ASE offers across the country to certify automotive service professionals. The ASE H3 Drive Train (Transit Bus) case studies are 5 cases and about 2,844 words.
1Repeat Driveline Vibration After U-Joint Replacement
A 40-foot low-floor transit bus with a rear-mounted engine and a two-piece driveshaft comes in with a driver complaint of a vibration felt through the floor between 35 and 45 mph, worst under light acceleration. Six weeks ago the shop replaced the rear U-joint on the forward shaft after a seized bearing cap was found.
581 words, about 3 min2Harsh 1-2 Shift After Valve Body Service
A transit bus with an electronically controlled automatic transmission (six forward speeds) had the valve body removed for a stuck shift solenoid. The technician reused the original valve body gasket, cleaned the separator plate, and reinstalled.
600 words, about 3 min3Wheel-Speed and Output-Speed Mismatch on a Retarder-Equipped Bus
A 60-foot articulated bus with a retarder-equipped automatic transmission reports intermittent ABS/traction warning lamps and a driveline shudder during low-speed turns. The transmission controller logs a ratio error between engine speed and output speed that appears only below 10 mph.
572 words, about 3 min4Rear Axle Oil Leak and Bearing Noise After Seal Replacement
A transit bus rear axle had the pinion seal replaced at 180,000 miles because of a leak at the companion flange. Two months later the axle is leaking again from the same area, and the driver reports a whine that is loudest at 45–55 mph and changes when the throttle is lifted (coast vs.
555 words, about 3 min5Intermittent No-Move Complaint on a Series-Hybrid Bus Driveline
A series-hybrid transit bus intermittently refuses to move from a stop. The driver reports that after a long regen braking event on a downhill route, the bus will not accelerate for several seconds; the dash shows a driveline warning, then it clears and the bus drives normally.
536 words, about 3 min