Automotive General Services Technician Model

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Lesson Plan Industry Sector
Transportation

Lesson Plan Originally Created By: Beau Sunahara

**Shift linkage, Interlock, & Detents (updated) by Beau Sunahara

Part of Unit: Transmissions and Drivetrains

Lesson Plan Overview / Details

In this lesson, students will demonstrate shifting gears on a manual transmission. 

Students will be able to list advantages and disadvantages of different types of linkages. 

Student will also accurately understand how an interlock and a detent works with internal linkage systems.

Student grouping will be entire class, as this lesson is primarily a lecture.

Lesson Time

1 Class period
55 Minutes

Prerequisites

  • Gears lesson
  • Synchronizer lesson

Standards

California Career and Technical Education Standards

California Academic Content Standards (Reinforced)

NATEF Standards

  • Manual Drive Train and Axles: Task C-10 Inspect, adjust, and reinstall shift cover, forks, levers, grommets, shafts, sleeves, detent mechanism, interlocks, and springs.
  • Manual Drive Train and Axles: Task C-5 Diagnose hard shifting and jumping out of gear concerns; determine necessary action.

Objectives and Goals

  • Students will be able to identify parts of a detent and inter-lock system
  • Students will be able to relate a shift pattern with what is actually happening inside a manual transmission
  • Students will be able to accurately describe the operation of the detent system
  • Students will be able to accurately describe the operation of the inter-lock system
  • Students will be able to accurately recognize transmission problems such as shifter popping out of gear and gears locked in a gear

Vocabulary

Detent balls
Detent balls also know as poppet balls are spring loaded steel balls used to help keep the shift rails in place. They generally have three positions: forward, middle, and back.
Inter-lock mechanism
The inter-lock mechanism is used to prevent a manual transmission from shifting into two gears at once. If one shift rail is moved in any of the three positions the two remaining shift rails are locked into place.

Activities in this Lesson

  • Shifting flash activity - Hooks / Set

    Teacher will show students the Website to show them what is actually happening when they shift a stick on a manual transmission vehicle.

    Students can select a gear on the flash animation to see what is happening inside the transmission.

    The teacher will show the students the actual parts that are being affected while the students change gears on the flash page.

    The teacher will ask a leading question: "What do you think will happen if a manual transmission were to shift into two gears at the same time?"

    Students can either answer aloud when called on, or all students can write down what they think would happen on a scrap sheet of paper.  This can be recalled when the teacher starts to lecture on the purpose of the inter-lock system.

    • transmission3.htm [ Go to Site ] This website has a flash activity where students can manipulate a shifter and see what happens inside the transmission.
  • Detent - Lecture

    The teacher will explain how the shift rails work in a manual transmission.

    The teacher will revisit the previous lecture of angled gears and how their design creates end-thrust.  The teacher will then ask students to make predictions on how end-thrust affects a shifter handle while it is in gear.

    The teacher will explain how detents are used to keep a manual transmission in a selected gear.

    The teacher will show parts through the use of a document camera if available; if no document camera is available, the teacher can hold up the parts as they are being explained.

    The teacher will also pass around parts so students get to handle the various parts being explained.

    The teacher will ask for questions at the end of the lecture to clarify explanations.

    Students will take Cornell-style notes during the lecture.

  • Video on Detent - Other

    The teacher will show a video of how the detent works.

    The teacher will quiz students during the video to check for understanding.

    Students will take Cornell-style notes on the video.

  • Inter-lock - Lecture

    The teacher will revisit the lesson on sychronizers and how the sleeves fit into the shift-forks.

    The teacher will explain that if a manual transmission ever shifted into two gears at the same time, a cataclysmic failure in the transmission would occur.  To prevent this type of damage, shift-forks have an inter-lock device to allow only one shift rail to be moved at a time.

    The teacher will ask for questions at the end of the lecture to clarify explanations.

    Students will take Cornell-style notes during the lecture.

    The teacher will need to express this is not the sole way to lock out gears, but this is just one example of how a transmission is able to lock the other rails out.

  • Inter-lock Video - Other

    The teacher will show a video of how the shift inter-lock works.

    The teacher will quiz students during the video to check for understanding.

    Students will take Cornell-style notes on the video.

  • Closure - Closure

    At the end of the lesson the teacher will give a short quiz.

    After the students turn in the quiz the teacher will go over the answers to give feedback on the questions.

Assessment

Assessment Types:
Teacher-Made Test,

During the lecture the teacher will call upon students to answer questions to check for understanding.

During the video the teacher will call upon students to answer questions to check for understanding.

This would be a mid-unit lesson so a quiz of pervious lessons on drive train and transaxle lessons would be given.

  • man trans fund quiz2.doc man trans fund quiz2.doc [ Download ] 2nd quiz given mid-unit