Part 1. Preparation and safety
Objective
- Disassemble the underside of the block.
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
- Keep a look out for any indications of engine failure.
Part 2: Step-by-step instruction
- Drain the block
The rotating assembly of an engine includes the crankshaft, connecting rods, and pistons.
Taking apart the rotating assembly is easier with the engine upside down, but there will still be some coolant trapped in the block, so keep a catch tray under the motor as you rotate it. There will be even more coolant left in the block if you were unable to remove one of the drain plugs earlier in the disassembly process.
- Remove the oil pump and tray
Some oil pumps are very easy to remove. Unscrew one bolt and simply pull off the pump.
Other pumps have two bolts and may also have a few other bolts that hold the pickup tube and screen in place.
As this pump is removed you can see the plastic collar that holds the oil pump drive rod onto the pump. If this collar is broken you will need to replace it.
If the engine has a windage tray to prevent oil from splashing onto the crankshaft, remove it now, with any dipstick tube or extension that might be inside the oil pan area.
- Look for engine problem evidence
Knocking noises were heard coming from deep inside this engine.
With the oil pan removed it is apparent that one of the rod bearings has disintegrated. The chunks of metal on the left are the remains of bearing shells that used to look like the undamaged ones on the right. Oil in this engine was being burned in the combustion chamber because of bad valve stem seals and guides. The oil level became too low, the pressure dropped, the rod bearing overheated, and the bearing was chewed up into fragments that ended up in the oil pan.
- Label the connecting rods and caps
Always mark the connecting rods before you remove them. The best way to do this is with a number punch set, but you could use a regular center punch.
You need to be able to turn the crankshaft, so use a crank turning tool, or reinstall the balancer and center bolt.
The connecting rod caps will need to be replaced in the same orientation, so label them in two places: above and below the parting line of the cap and rod body. It is a good idea to also label the main caps of the block in the same way.
