Machine diagnosis

Part 1. Preparation and safety

Objective

• Identify reasons for machining components.

Personal safety

Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection - such as rubber gloves and barrier cream
• Respiratory equipment - such as face masks and valved respirators

If you are not certain what is appropriate or required, ask your supervisor.

Safety check

• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.

Points to note

• When the inspections and measurements are completed, you will be able to diagnose what parts need machining and which need replacing.

Part 2: Step-by-step instruction

1. Diagnose parts for machining
   When the inspections and measurements are completed, you will be able to diagnose what parts need machining and which need replacing. Here are a few examples:
   Both boring and honing the cylinders is quite often necessary, which means that the pistons will need to be replaced.
   A block may have a misaligned main bearing bore, or a warped deck, in which case both will need to be cut straight.
   The head could be warped and it could have bad valve seats and guides.
   If a connecting rod bearing has broken, then that rod might be bent or twisted and need to be replaced, and the other rods may need resizing as well.
   The crankshaft may also need to be cut as well as polished to bring it back to a usable state.