Part 1. Preparation and safety
Objective
- Disconnect and remove underside engine connections and 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
- Double check to make sure the battery is disconnected.
- Ensure the vehicle is supported by at least two correctly rated jackstands.
- 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
- Minimize the risk of stripping exhaust bolts or nuts by using a six point socket or spanner instead of twelve point.
- Check to ensure that all connections have been removed.
Part 2: Step-by-step instruction
- Remove upper bolts from transmission
All transmissions have some type of bellhousing that bolts to the engine block. On many manual transmissions the bellhouse is a separate piece of the transmission that houses the flywheel and the clutch plate and disc. Some types of manual transmissions can be separated from the bellhousing while they are still connected to the block. Most automatic transmissions have the bellhousing permanently molded as a fixed part of the transmission. In either case the bellhousing will be connected to the block with a number of bolts.
On most engines there will be two or more upper bolts that are much easier to get to from the top. A stubby wrench is often the best tool when space is limited.
- Raise the front of the vehicle
Make sure that the vehicle is on a flat hard surface, so that the wheels of the engine hoist can roll smoothly.
Never work under a vehicle that is only supported by a jack. A jack is only used to raise one end of a vehicle far enough for it to be lowered onto stronger, safer, and more stable jackstands.
Never use cinder blocks to support a car, they are brittle and breakable, and may collapse under the weight.
When you have it resting on at least two correctly rated jackstands, give the vehicle a firm shake. If it is at all wobbly, reposition the stands until it is absolutely solid and safe.
- Remove the starter motor
Remove the bellhousing or torque converter cover if there is one, so that you can get to the starter.
Double check to make sure that your battery is disconnected, then undo the starter bolts alternately until one of them is free. Then thread that same bolt back in by hand for a few turns. Now remove the other bolt. Support the weight of the starter with one hand and remove the remaining bolt. Starter motors are heavy and the wires that connects to them are usually not very long, so have a box or some blocks of wood ready to rest this component on as it comes loose.
Disconnect the bigger of the wires from the starter. This wire comes from the positive side of the battery, or on some engines from a remote starter solenoid. Then disconnect the other, or sometimes two other, smaller wires. Pay close attention to which wires went to each place on the starter. As soon as you have the starter secured, label the wires and record their numbers with any other notes you need to reconnect them later.
- Disconnect the torque converter
With automatic transmissions, the disc that connects the crankshaft and transmission is called the flexplate. On a manual transmission the disc is called a flywheel and has other parts of the clutch assembly connected to it. An automatic transmission has a torque converter instead of the clutch assembly. To separate the engine block from the transmission, you need to remove the bellhousing bolts that attach it to the block, undo the engine mounts and the engine with the flywheel or flexplate attached would be clear to pull directly away from the transmission and then up and out. For manual transmissions you just need to be aware that the transmission shaft needs to clear first before hoisting up.
The torque converter of an automatic is physically bolted to the flexplate, and it's better to disconnect the converter and leave it in place on the transmission. There are usually three or four bolts that make the connection. You will need to rotate the flexplate by hand so you can remove the bolts one by one. If you don't have a special tool for rotating flexplates, you can clamp a pair of vice grips on the flexplate and spin it a little at a time. Rotating the flexplate turns the engine over, so removing the spark plugs will reduce the compression resistance of the engine and make this job a lot easier.
When all three bolts have been removed, push the converter to the rear. It should spin freely. Internally, the engine is now disconnected from the transmission.
- Disconnect the exhaust
Exhaust bolts can often be corroded and sometimes they are completely seized. One way to minimize the risk of stripping a bolt or nut is to make sure you use six point tools instead of twelve point.
It is better for a stubborn bolt to break off, than for a nut to strip so that you are unable to remove it. When that happens you may need to cut the bolt or stud with a hacksaw or oxyacetylene torch.
The exhaust flange can also be difficult to remove. Be patient and try not to damage other parts of the car while you're prying it loose.
Sometimes it is necessary to use a lot socket wrench extensions to get at the nuts on the exhaust manifold.
- Check all underside linkages
Look around the engine bay to check the connections. All of the lines, cables, or hoses that connect the engine to the chassis should now be clear.
- Disconnecting the transmission
To remove this engine we need to leave the transmission in place, so we need to unbolt the rest of the bellhousing from the block.
The upper bolts were removed before the vehicle was raised, but there are two middle and two lower transmission bolts still in place. Some engines have two pins on either side on the bellhousing. These are alignment dowels.
First remove the middle bolts. If a bolt is too close to the firewall to fully unthread, thread it back in but leave it loose so that you can get it out later when the hoist is able to lift the engine. Loosen the bolts in the lower area, but don't unthread them completely and take them out. You may need to use a double extension to get up in between the transmission and the exhaust pipe. A flex socket on the end of an extension is the easiest way to turn corners and get at the bellhousing bolts from under the car, where you may not even be able to use a stubby wrench.
The two lower bolts should now be the only two bolts left connected on the bellhousing.
Remove any bolts that hold the two halves of the engine mounts together, and any bolts that may hold the engine mounts to the chassis of the vehicle.
Once the engine mount bolts are out, the motor is just sitting ready to be picked up. It's connected to the frame at the two engine mount positions. The back end is supported by the transmission mount that is sitting on the frame cross-member.
