ASE S3 Drive Train (School Bus) case studies
ASE S3 Drive Train (School Bus) · Put your knowledge to work in context.
The ASE S3 Drive Train credential is one of the school bus certifications offered within the ASE certification test series administered by the National Institute for Automotive Service Excellence. It is intended for service professionals who diagnose, service, and repair the drivetrain systems of school buses - a fleet environment where reliability and safety margins matter more than in most passenger-car work, and where technicians are expected to reason about heavy-duty components, load, and duty cycle. The ASE S3 Drive Train (School Bus) case studies are 5 cases and about 2,406 words.
1Clutch Slip on a Loaded Hill Route
A 2016 conventional school bus with a manual transmission and 78,000 miles is used on a rural route with two long 6% grades. The driver reports that on the second grade, with a full load of 60 students, engine rpm climbs about 300 rpm above what road speed should command whenever the pedal is held steady, and the smell in the cab is sharp.
499 words, about 2 min2Automatic Bus Harsh 2-3 Shift After Fluid Service
A 2014 transit-style school bus with an automatic transmission and 112,000 miles had its fluid and filter changed at a quick-service shop two weeks ago. Since then the driver reports a harsh, banging 2-3 upshift, especially when the bus is cold, and a slight flare on the 3-4 shift when climbing with a full load.
494 words, about 2 min3Rear Axle Whine That Changes With Throttle
A 2012 school bus with a single-speed rear axle and 145,000 miles develops a whine the driver notices most at 45-55 mph. The noise is loudest on deceleration (coast) and gets quieter when the throttle is applied.
484 words, about 2 min4Driveline Vibration at Highway Speed
A 2017 school bus with a two-piece driveshaft and a center support bearing develops a vibration felt in the floor and seats that begins at 52 mph and peaks at 58 mph, then diminishes above 62 mph. It is not felt in the steering wheel.
465 words, about 2 min5Manual Transmission Pops Out of Gear on Downhill
A 2013 school bus with a manual transmission and 96,000 miles pops out of third gear when the driver lifts off the throttle on a downhill grade with a full load. It stays in gear under acceleration and on flat ground.
464 words, about 2 min