Verify correct camshaft timing.
Lesson Plan for
AUT 188-189/AUT 293
Automotive Service Technology Section D/Automotive Special Problems
Course HS Title: / Automobile Service Technology/Special Problems / Program:KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No. / KCTCS Course Title
Introduction/Context / This lesson will instruct the student on how to verify correct camshaft timing. 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.
Prepared By / School / Date:
Grade Level / No. Students / No.IEP's: / Lesson Length:
Task
Verify correct camshaft timing.
No. / Objective
1 / Given the proper tools and instruction, the student will be able to verify correct camshaft timing, and pass a written test covering the task with 100% accuracy.
Connections:
Skills Standards:OH 001
OH 002
OH 003
OD 002
OD 003
OD 005
Common Core Technical Standards:
TD-SYS-2
New Common Core Standards:
RST 11-12.2
RST 11-12 3
INSTRUCTIONAL MATERIALS/TECHNOLOGY
Teacher Designed Materials and Other Handouts
Textbooks and Workbooks
Jack Erjavec / Automotive Technology: A Systems Approach / 4th Edition / Thomson/Delmar / 236-257
Web Addresses
Today's Class / Melior / www.todaysclass.com
Equipment
As Needed / Advance Timing Light / Various
Content/Presentation/Demonstration Outline
GEAR DRIVE: Inform students that this is when a gear on the crankshaft meshes directly with another gear on the camshaft. The gear on the crankshaft is usually made of steel. The gear on the camshaft may be steel for heavy-duty applications, or it may be aluminum or pressed fiber when quiet operation is a major consideration. Let students know that the gears are helical in design because helical gears are stronger and also tend to push the camshaft backward during operation to help prevent the camshaft from walking out of the block.
CHAIN DRIVE: Inform students that this is when the sprockets on the camshaft and the crankshaft are linked by a continuous chain. The sprocket on the crankshaft is usually made of steel. The sprocket on the camshaft may be steel for heavy-duty applications. Let students know that when quiet operation is a major consideration, an aluminum sprocket with nylon covering on the teeth is used. Explain to students that nearly all OHV engines use a chain drive system. Chain drives are also used on many OHC engines, especially DOHCs. Often multiple chains are used and arranged in an elaborate fashion. Inform students that these chain arrangements use a chain tensioner to maintain proper tightness and different silencing pads to reduce the noise of the chain.
BELT DRIVE: Inform students that this is when the sprockets on the crankshaft and the camshaft are linked by a continuous neoprene belt. The belt has square-shaped internal teeth that mesh with teeth on the sprockets. The timing belt is reinforced with nylon or fiberglass to give it strength and prevent stretching. This drive configuration is limited to overhead camshaft engines. Explain to students that the camshaft and crankshaft must always remain in the same relative position to each other. To obtain the correct initial relationship of the components, timing marks on the crankshaft and camshaft are aligned during assembly.
Let students know that if wear exists on any component, replacement of the entire assembly is necessary. Wear in the chain, gears, or sprockets results in poor engine performance.
For correct valve timing, and to verify correct camshaft timing, the camshaft drive must be installed so that the camshaft and crankshaft are in time with each other. Both sprockets are held in position by a key or possibly a pin. Inform students that there are factory timing marks on the crankshaft gear or sprocket and on the camshaft gear or sprocket. The timing marks on all the gears must be positioned according to the manufacturer's instructions.
Instruct students that if they setting the timing on a set of sprockets that use a chain, the chain is installed on the crankshaft gear first, then around the camshaft sprocket. Remind students to never wind a chain onto the gears or use a screwdriver, pry bar, or hammer to force a chain into position. Prying or pounding on the chain damages the links, which will cause the chain to stretch and fail. Inform students to carefully place the entire assembly as a unit onto the shafts by pressing both gears evenly, keeping the keyways aligned.
Applications/Practice
Evaluation and feedback Prior to Testing or Lab Work
STUDENT ASSESSMENT:(Assess student progress with performance criteria.)
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.)