Part 1. Preparation and safety
Objective
- Disassemble and remove the valve train.
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
- Some parts must be reassembled back into the same cylinders they were removed from. Use an organizer tray to hold parts that are removed and ensure they are placed in their correct order.
Part 2: Step-by-step instruction
- Remove rocker arms
The valve train is made up of all of the parts that are associated with the opening and closing of the valves. The valve train controls the mechanical timing of these events. The camshaft, lifters, pushrods, rocker arms, valve springs and the valves themselves all make up the valve train.
Start with the rocker arm nuts which are at the fixed pivot points of the rocker arms. If the engine has rocker shafts that the rocker arms are mounted on, the entire shaft is usually unbolted and lifted off as one piece. As the rocker arms come off, make sure the pivot ball that is under the rocker nut stays with its respective rocker arm.
- Use an organizer tray
It's very important that as you take the valvetrain apart, everything that can be re-used has to be organized so that during reassembly it goes back into the exact position that it came from. If parts are not matched to their original placements, with their companion parts, excessive wear will occur. Some tools suppliers have special valvetrain organizer trays for this purpose. New components should be uniform in size and, of course, don't need to be matched.
- Remove pushrods
As you remove the pushrods, make sure the upper end stays in the up position. If you reassemble them upside down or get them mixed up, they will wear out a lot faster.
- Remove valve lifters
There are special pick tools that make it easier to pull out clean valve lifters, but you can also use a small flat head screw driver to do this.
If any or all of the lifters are gummed up with dirty oil and don't want to come out, leave them where they are. They can be removed from the bottom after the camshaft has been removed.
Unless they are obviously unsalvageable, put them all in the organizer tray for now. They will be assessed later to see if they can be reused or not.
