ASE A3 case studies
ASE A3 · Put your knowledge to work in context.
ASE A3, Manual Drive Train and Axles, is one of the subject-area tests in the ASE automobile and light truck certification series administered by the National Institute for Automotive Service Excellence. It is intended for working technicians and serious students who diagnose, service, and repair clutch assemblies, manual transmissions and transaxles, drive shafts and half-shafts with their universal and constant velocity joints, differentials, and the axles and four-wheel drive components that put torque to the ground. The ASE A3 case studies are 5 cases and about 3,777 words.
1Engine Flare Under Load on a 5-Speed Pickup
A 2006 rear-wheel-drive pickup with a 4.0 L V6 and a 5-speed manual transmission comes in with 138,000 miles on it. The owner reports that when towing a trailer up a grade in 4th gear at about 2,800 rpm, the engine flares roughly 500 rpm but road speed does not increase, and there is a faint burning smell after long climbs.
761 words, about 4 min2High-Gear Whine in a 6-Speed Transaxle
A 2013 front-wheel-drive sedan with a 6-speed manual transaxle and 105,000 miles is brought in for a whine heard at 55-70 mph. The noise is loudest during light acceleration and steady cruise and nearly disappears when the driver lifts off the throttle.
752 words, about 4 min3Lift Kit Vibration and Clunk on a Two-Piece Driveshaft
A 2011 rear-wheel-drive 4x4 pickup with a two-piece steel driveshaft and a center support bearing was fitted with a 6 in suspension lift 8,000 miles ago; only a 1.5 in transfer case drop kit was installed with it. The owner complains of a vibration from 45-55 mph that is worse when accelerating or climbing a grade and disappears when coasting or when the transmission is in neutral.
762 words, about 4 min4Limited-Slip Chatter and a Load-Sensitive Howl
A 2008 rear-wheel-drive three-quarter-ton truck with a 4.10 axle and a limited-slip differential has 155,000 miles. The rear axle was serviced 2,000 miles ago: the cover was resealed and the housing refilled with 80W-90 GL-5 gear oil that carries no limited-slip rating, and no friction modifier was added.
755 words, about 4 min5Low-Speed Bind and a Highway Vibration on a 4WD SUV
A 2014 four-wheel-drive SUV with an electronically controlled transfer case, an independent front suspension with half-shafts, and 118,000 miles comes in with two complaints. The first is a shudder felt through the floor and steering wheel during tight low-speed turns, especially in a parking lot.
747 words, about 4 min