This lesson will instruct the student on how to remove and reinstall transmission/transaxle and torque converter, inspect engine core plugs, rear crankshaft seal, dowel pins, dowel pin holes, and mating surfaces. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in an Automotive Repair Facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to an automobile accident or create customer satisfaction issues.
Remove and reinstall transmission/transaxle and torque converter; inspect engine core plugs, rear crankshaft seal, dowel pins, dowel pin holes, and mating surfaces.
Given the proper tools and instruction, the student will be able to remove and reinstall transmission/transaxle and torque converter, inspect engine core plugs, rear crankshaft seal, dowel pins, dowel pin holes, and mating surfaces, and pass a written test covering the task with 100% accuracy.
Instruct students that the first step in removing the transmission is to disconnect the battery. Tell them that removing the transmission from an RWD vehicle is generally more straightforward than removing one from an FWD model, as there is typically one cross member, one drive shaft, and easy access to cables, wiring, cooler lines, and bell housing bolts. Explain that transmissions in FWD cars, because of their limited space, can be more difficult to remove as you may need to disassemble or remove large assemblies such as the engine cradle, suspension components, brake components, splash shields, or other pieces that would not usually affect RWD transmission removal.
On RWD vehicles, tell students to raise the vehicle and drain the transmission fluid. Have them mark the drive shaft at the rear axle before disconnecting it to avoid run-out-related vibrations, then they can remove the drive shaft.
On FWD vehicles, tell them to attach a support fixture to the engine, raise the vehicle, and drain the fluid. Have them remove the front wheels and follow the service manual to remove the front axles.
Instruct students to disconnect manual linkages, vacuum hoses, electrical connections, speedometer drives, and control cables. Tell them the inspection cover between the transmission and the engine should be removed next. Have them mark the position of the converter to the flexplate to help maintain balance or runout. Explain that it will be necessary to rotate the crankshaft to remove the converter bolts, and that this can be done by using a long ratchet and socket on the crankshaft bolt or by using a flywheel turning tool if space permits.
Tell students to position a transmission jack before removing any cross member or bell housing bolts. Explain that the use of a transmission jack also allows for easier access to parts hidden by cross members or hidden in the space between the transmission and the vehicle’s floor pan. While supporting the transmission with a transmission jack, have students remove the cross member or transmission mounts, and then remove the starter and bell housing bolts.
Tell students to now pull the transmission away from the engine. Let them know that it may be necessary to use a pry bar between the transmission and engine block to separate the two units. Instruct them to make sure the converter comes out with the transmission. Let them know that this prevents bending the input shaft, damaging the oil pump, or distorting the drive hub.
After separating the transmission from the engine, instruct students to retain the torque converter in the bell housing. Let them know that this can be done simply by bolting a small combination wrench to a bell housing bolt hole across the outer edge of the converter. Inform them that when the transmission is removed, it is an opportune time to check the engine’s rear crankshaft seal. Explain that most late-model rear main engine seals are one piece and accessed by only engine or transaxle/transmission removal.
Tell students to be sure to check all bell housing bolt holes and dowel pins. Cracks around the bolt holes indicate that the case bolts were tightened with the case out of alignment with the engine block. Let them know that the case should be replaced if any cracks are present. Explain that a transmission case is very thin, and welding may distort the case, and it is not possible to determine if a repair will hold.
Inform students that if any of the bolts that were removed during disassembly have aluminum on the threads, the thread bore is damaged and should be repaired. Let them know that thread repair entails installing a threaded insert, which serves as new threads for the bolt, or re-tapping the bore. Let them know that after the threads have been repaired, they should thoroughly clean the case.
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Evaluation and feedback Prior to Testing or Lab Work
Objective 1. / Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist will be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.
STUDENT ASSESSMENT: (Assess student progress with performance criteria.)
Objective 1 / Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)