36 Questions
What is the primary reason for ensuring all oil passage drillings in the crankshaft are clean and free of obstructions?
To allow for proper inspection of the crankshaft
What should you do if you come in contact with corrosive chemicals during the cleaning process?
Follow recommended first aid procedures
Why is it important to keep compressed air and high-pressure water away from your body during the cleaning process?
To avoid accidents and personal injury
What should you do before lifting heavy components during the cleaning process?
Use proper equipment for lifting operations
What is the primary purpose of wearing personal protective equipment during the cleaning process?
To prevent personal injury and protect yourself from hazardous materials
Why is it important to familiarize yourself with WHMIS sheets for all chemicals and solvents involved in the cleaning process?
To understand the properties and hazards of the chemicals and solvents
What is the primary concern when oil passages are not properly cleaned?
Foreign material may be flushed into the bearings
What is the purpose of coating the crankshaft with light preservative oil and wrapping it in plastic?
To prevent corrosion during storage
What is the recommended course of action for damaged threads in the crankshaft?
Clean the threads with a tap or have them repaired by a machine shop
What is the purpose of inspecting the seal surface area on the crankshaft?
To check for grooves or damage to the seal surface
What is the recommended method for removing a worn wear sleeve from a crankshaft?
Score the surface in several places with a chisel
What is the most accurate method for detecting cracks in a crankshaft?
Fluorescent magnetic particle (Magnaflux) inspection
Why is it essential to inspect the crankshaft main bearing, connecting rod bearing, and thrust surfaces?
To check for scoring or ridging
What is the recommended method for cleaning the crankshaft?
Hot tank, mechanical parts washer, or steam cleaner
What happens if more than half of the threaded holes in the crankshaft are damaged?
The crankshaft may need to be replaced
Why is it crucial to blow dry the crankshaft with compressed air after washing?
To prevent rust formation
What is the primary concern when inspecting a crankshaft?
Determining the reusability of the crankshaft
Why should the spindle of the micrometer be positioned carefully when measuring the journal surface?
To prevent incorrect measurements due to oil holes and fillet radius
What is the purpose of measuring the distance between the thrust surfaces of a crankshaft?
To determine thrust surface wear
How is crankshaft straightness typically checked?
Mounting a dial indicator to the bench and rotating the crankshaft
What is the purpose of regrinding journals of a crankshaft?
To restore worn journals to exact dimensions
What is stamped on the front counterweight of a reground crankshaft?
The amount of material removed from the journals
Why should crankshafts with cracks in critically loaded areas generally be replaced?
Because they are no longer serviceable
What is the purpose of measuring the main and connecting rod journals?
To determine wear, out of round, and taper
Who should interpret cracks to determine the reusability of a crankshaft?
A specially trained personnel
What is the purpose of checking the straightness of a crankshaft?
To ensure the crankshaft is serviceable
What is the purpose of grinding a crankshaft's journals?
To restore the journals to a usable condition
Why are undersize bearings used in a reground crankshaft?
Because they fit the reground crankshaft's journals
What is the purpose of reboring a block's bearing bore?
To install an oversize bearing
How are bearings commonly identified?
By stamped dimensions on the back of the shell
What happens to the distance between the thrust surfaces when they are reground?
It increases
What is the purpose of inspecting the crankshaft gear?
To check for breakage and signs of wear
Why is it necessary to consult the manufacturer's service information for crankshaft gear removal and installation?
Because the procedure varies depending on the engine design
What is the purpose of removing the crankshaft gear?
To perform certain crankshaft service procedures
What is the result of grinding a crankshaft's journals to different undersizes?
All journals are ground to the same dimension
What is the purpose of hard chromium plating or welding a worn crankshaft journal?
To repair the journal if the cost of repair is less than a new crankshaft
Study Notes
Safety Precautions
- Wear personal protective equipment (eye protection, apron, gloves, hearing protection, breathing protection) when working with corrosive chemicals, petroleum solvents, high-pressure water, steam cleaning, and compressed air.
- Keep compressed air and high-pressure water away from the body.
- Work in a well-ventilated area when using chemicals and solvents.
- Familiarize yourself with WHMIS sheets for all chemicals and solvents involved in cleaning processes.
- Follow recommended first aid procedures if you come in contact with corrosive chemicals.
Crankshaft Cleaning
- Clean the crankshaft thoroughly before inspection to remove oil and deposits.
- Use petroleum solvent, hot tank, mechanical parts washer, or steam cleaner to clean the crankshaft.
- Blow the crankshaft dry with compressed air after cleaning.
- If not reinstalling the crankshaft immediately, coat it with light preservative oil and wrap it in plastic to prevent rust formation and dirt contamination.
Crankshaft Inspection
- Visually inspect the crankshaft main bearing, connecting rod bearing, and thrust surfaces for scoring and ridging.
- Inspect machined surfaces (journals and fillet areas) for discoloration, which indicates excess heat.
- Inspect threaded holes in the nose and flange for damaged threads.
- Inspect the seal surface area for grooves, and polish out minor grooves (less than 0.010" or 0.25 mm) for reuse.
Crack Detection
- Check crankshafts for cracks using dye check, magnetic particle, or fluorescent magnetic particle (Magnaflux) methods.
- Inspect critical areas of loading on the crankshaft for fatigue cracks.
Measurement
- Measure machined and load-bearing surfaces of the crankshaft to determine serviceability.
- Measure main and connecting rod journals to determine wear, out of round, and taper.
- Measure the distance between thrust surfaces to determine thrust surface wear.
- Check crankshaft straightness or runout using V-blocks and a dial indicator.
Crankshaft Reconditioning Procedures
- Straighten crankshafts if runout is within manufacturer's limits, but recheck for cracks after straightening.
- Regrind journals that are worn beyond manufacturer's minimum specifications to an undersize dimension.
- Use undersize bearings on reground crankshafts to provide correct bearing clearance.
- Oversized bearings can be installed in oversized bores.
Learn about the safe procedures and personal protective equipment required for inspecting and measuring crankshafts. Understand the importance of safety in the cleaning and inspection process. Identify the necessary precautions to take when working with corrosive chemicals and compressed air.
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