This lesson will instruct students on the proper procedures to dismount, inspect, and remount tire on wheel, and balance wheel and tire assembly (static and dynamic). 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.
Dismount, inspect, and remount tire on wheel; Balance wheel and tire assembly (static and dynamic).
Given the proper tools and instructions from the vehicle manufacturers shop manual or computer software, students will be able to dismount, inspect, and remount a tire on the wheel, balance wheel and tire assembly (static and dynamic), and pass a written exam on the task with 100% accuracy by the end of the course.
Instruct students on the proper procedures to dismount, inspect, and remount tire on a wheel:
1. Remove the valve core to deflate the tire. 2. Remove any wheel weights from the wheel. 3. Mount the tire on the tire changer and dismount the tire according to the instructions of the manufacturer of the tire changer. CAUTION: Failure to follow manufacturer's instructions when operating a tire changer can result in serious personal injury. NOTE: In order to make bead removal easier and to prevent damage, apply a rubber lubricant to both beads before dismounting.
4. Inspect the wheel and valve stem and answer the questions on the attached worksheet. 5. Using the procedure outlined on the worksheet, inspect the tire that needs to be mounted. a. Inspect the beads. b. Check for any punctures in the tire. Patch repairable punctures before mounting. c. Check for wear or damage to the tire tread or sidewall. Discard defective tires. d. Check for and remove any foreign material from inside the tire. 6. Clean the bead seating area of the rim before mounting the tire.
7. Mount the tire on the wheel according to the manufacturer's instructions for the tire changer. a. Apply a rubber lubricant to both beads before mounting. CAUTION: Do not exceed 25 psi when popping the tire beads. Keep fingers clear of the tire when seating the bead on the rim. b. Inflate the tire to 40 psi to seat the beads after they popped. c. Install the valve core and adjust the tire pressure to the recommended pressure. d. Check for leaks at the valve core. Repair any leaks. e. Install the valve stem cap or extension. f. Check for leaks around both tire beads. Repair any leaks. g. Inspect the tire for uneven bead seating and correct as needed. 8. Proceed as indicated on the attached worksheet and have the instructor sign off.
The instructor will demonstrate proper use of tire changer and wheel balancer, while stating all safety rules of machine and care needed around a tire pressure sensor. Instruct students that static imbalance will cause tire to vibrate up and down, dynamic imbalance will make tire vibrate from side to side and up and down. A wheel assembly is balanced by adding wheel weights to the side opposite the heavy area. There are various types and sizes of wheels weights. Most press fit onto the wheel. Some mag wheels use stick on weights.
Instruct students that to static balance a wheel and tire assembly, add wheel weights opposite the heavy area of the wheel. If a large amount of weight is needed, add half the inside of the wheels and half to the outside of the wheel. This helps keep dynamic balance correct. To dynamic balance a wheel and tire, you must add weights exactly where needed. The dynamic balancing machine will indicate where and how much weight to add to bring the assembly into dynamic balance.
When balancing a wheel assembly, tell students to follow these safety rules: • Wear eye protection • Remove rocks and other debris from tire tread • Place a jack stand under car when using on car balancer • When using the engine to spin the wheels, do not exceed 35 mph • With a limited slip differential, raise both rear wheels off the ground when using on car balancer • Follow the operating instructions provided with the wheel balancing equipment.
Evaluation and feedback Prior to Testing or Lab Work
Assessment Plan Formative: 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 / depth of knowledge. 3/ Adaptations and/or accommodations for special needs students will be added if required.
STUDENT ASSESSMENT: (Assess student progress with performance criteria.)
Assessment Plan Summative: Objective 1 / Summative assessment / written test questions on stated objective / depth of knowledge 3/ 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.)