Tài liệu học tập cơ bản khái quát về động cơ và các bộ phận trên ô tô phiên bản tiếng anh. Tài liệu này nhằm giúp chúng ta tiếp cận được cấu tạo chức năng của các bộ phận của xe. Với tài liệu này giúp các bạn sinh viên ngành cơ khí ô tô tiếp cận được những kiến thức cơ bản về ô tô và đồng thời nâng cao kiến thức tiếng anh. Bộ tài liệu này được soạn thảo bởi trường đào tạo và huấn luyện nghề ở Canada.
Chapter 42 Automatic Transmission and Transaxle Service Identification • Proper identification is essential but can be difficult • Pan shape can sometimes be used • Best method is to used the ID numbers stamped on the case or on a metal tag • Many use bar codes for quick ID Fluid Check • Check on a flat level surface • Follow manufacturers service guidelines to accurately check fluid level • Low and excessively high fluid levels can cause aeration • Examine the fluid carefully Transmissions Without a Dipstick • Checked similar to a manual transmission • Done to prevent overfilling and causing damage • Some transmissions use a fluid level sensor to alert the driver Fluid Changes • Change when there is an indication of oxidation or contamination • Periodic changes are part of vehicle maintenance program • Change at normal operating temperature • Inspect the pan for deposits and particles • Follow all service procedures for fluid and filter changes Sources of Transaxle Fluid Leaks Checking Mounts • Engine and transmission mounts are important to transaxle operation • Inspect mounts for looseness and cracks • Watch the torque reaction when applying power in forward and reverse Diagnosis of Noise and Vibration Problems • Many noise and vibration problems may be caused by: – – – – – Engine Drive shaft, U-joints, or CV joints Wheel bearings Wheel/tire imbalance Or other conditions Checking the Torque Converter • Problems may include: – abnormal noises – poor acceleration in all gears – normal acceleration but poor high speed performance – transmission overheating Throttle Valve (TV) Linkages • TV linkage may control downshift valve and TV • Throttle pressure is used to indicate engine load • Influences shift timing • Can cause early upshifts or harsh delayed upshifts TV Circuit Kickdown Switch Adjustment • Used on some transmissions to indicate WOT and force a downshift Band Adjustment • Refer to the clutch and band application chart to determine if slipping during shifting can be corrected by band adjustment • May be adjusted externally with a torque wrench Transmission Overhaul • Before removing the transmission: – – – – – Inspect the torque converter bolts and TC Index the flexplate to the converter Remove the battery ground cable Disconnect linkages, cooler lines, and wiring Remove the dipstick tube Transmission Overhaul (cont’d) • Inspect the flexplate for cracks or damage • Inspect the TC drive lugs, check for ballooning, check balance weights, pilot and drive hub • Check flexplate and converter drive hub for runout Transmission Overhaul (cont’d) • Replace TC if any doubt of its condition • Inspect drive chains for stretch and side play • Check all pumps, valve bodies, and cases for warpage • Keep parts absolutely clean • Use correct size thrust washers • Soak friction plates in clean ATF before installing Transmission Overhaul (cont’d) • • • • Always use new gaskets and seals Ensure all wiring is connected Flush the transmission cooling system Use only lint-free cloths Installation • • • • • • Check alignment dowels and holes Make sure pilot hole in crank is smooth Make sure pilot hub is smooth and lubricated Flush the converter Check converter endplay and height Pour one quart of ATF into the TC before mounting to the transmission ... weights, pilot and drive hub • Check flexplate and converter drive hub for runout Transmission Overhaul (cont’d) • Replace TC if any doubt of its condition • Inspect drive chains for stretch and side... Dipstick • Checked similar to a manual transmission • Done to prevent overfilling and causing damage • Some transmissions use a fluid level sensor to alert the driver Fluid Changes • Change when there... with a torque wrench Transmission Overhaul • Before removing the transmission: – – – – – Inspect the torque converter bolts and TC Index the flexplate to the converter Remove the battery ground