Automotive Service Technician (AST)

Second Period Package (36 Modules) Comments

Date: 6/3/2021 6:24:55 AM
Module: 090201d
Version: 21
Page: 23
Comment: Answer to question #5 is incorrect. It states that bearings matched to the crankshaft should be oversized. This is incorrect. The bearings needed are undersized due to the inside diameter. The bearings now form a smaller diameter which makes them undersized. The bearing manufactures will identify this on the back of the bearing with a mark like this - 0.010us. The correct answer should be A
Status: Implemented

Date: 6/3/2021 6:30:32 AM
Module: 090201e
Version: 21
Page: 38
Comment: Answers for question #3 are incorrect. The picture was changed in the last revision, but the answers were not changed to match the new picture.
Status: Update in Progress

Date: 6/22/2021 11:12:00 AM
Module: 090201g
Version: 090201mp21.0_updated
Page: 26
Comment: It states that a cam follower is a second class lever because the fulcrum is at the end rather than the middle. However the placement of the effort (cam) and load (valve spring) are not considered. A second class lever has the load in the middle and the effort at the end opposite the fulcrum. This gives allows a smaller effort force moving over a large distance to move a heavy load a small distance (like a wheelbarrow). In the case of the cam follower, the fulcum is an one end, the effort (action of the cam) is in the middle and the load (valve spring to be compressed) is at the other end. This makes the cam follower a third class lever. In a third class lever, the load travels farther than the effort which correlates to valve lift being greater than cam lift (rocker ratio).
Status: Approved for Review

Date: 6/3/2021 6:30:50 AM
Module: 090201i
Version: 21
Page: 17
Comment: Figure 17 is incorrect. The picture is NOT an impeller wheel. (It is a differential drive pinion)
Status: Update in Progress

Date: 6/22/2021 10:46:15 AM
Module: 090201m
Version: 090201mp21.0_updated
Page: 14
Comment: The paragraph that begins with "Inspect all exhaust system heat shields..." below figure 16 is identical to the paragraph higher up on the page (one paragraph above figure 16)
Status: Approved for Review

Date: 6/22/2021 11:55:35 AM
Module: 090201o
Version: 090201op21.0_updated
Page:
Comment: The calculation of the increase in boiling point of coolant due to an increase in pressure has some errors. The ILM states that 3.25F is 2C. This is not correct -one degree Celsius is 1.8 times larger than one degree Fahrenheit. This error shows up in the calculation as the final answer calculted in fahrenheit is 257.5F. 257.5F is actually 125.3C not 128C as is calculated using metric. Using 2C is equal to 3.6F, you calculate 212F + (14 *3.6F) = 262.4F. 262.4F is equal to 128C. Also the starting point for the calculation is given at 212F (100C) (the boiling point of water) not sure why that is used rather than 225F (107C) given for a 50/50 mix on pg 7. The calculation is the for the boiling point elevation of coolant, not water.
Status: Approved for Review

Date: 6/22/2021 11:12:23 AM
Module: 090202b
Version: 090201mp21.0_updated
Page: 1
Comment: Objective one for manual TRANSMISSIONS states "Describe the purpose, operation and construction of a manual TRANSAXLE and and its components."
Status: Approved for Review

Date: 5/13/2021 9:50:15 AM
Module: 090204c
Version:
Page:
Comment: Self-Test Question 6 asks which gears are used on remote final drive assemblies; this topic is not covered in the module.
Status: Approved for Review

Date: 6/3/2021 6:19:28 AM
Module: 090205c
Version:
Page:
Comment: I have had student come out of the AIT exam totally confused asking me "what is multiplexing?" as there is a question on the exam about multiplexing. There is currently no mention of multiplexing in the 1st or 2nd period modules. It was in the older 2nd period material. I believe that we need to add a paragraph or two as an overview of multiplexing to this module.
Status: Declined


Archived Comments

Year: 2020

1/6/2020 9:35:05 AM
Module: 090202a
Version: 21
Page: 31
Comment: Figure 34 is missing
Status: Implemented