How To: Remove and Install Cams and Set Engine Timing

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How to Remove Camshafts:
Often, as part of a valve clearance inspection, one or more shims will have to be replaced. The typical approach is to use a special tool to leverage the lifter downward and access the shim. In my opinion, this has two drawbacks: First, the special tool isn't cheap, isn't readily available, and isn't easy to use. Second, if you have multiple shims to swap, doing them one at a time won't allow you to see what shims are installed in each lifter.

In my experience, removing the camshafts is the better approach. It gives you plenty of room to work, allows you to see what shims are installed in all of the lifters (possibly allowing you to swap between cylinders to get clearances back in spec) and makes shim access quite easy.

Here's how you remove and install the camshafts. The general approach is as follows:
  • Remove the spark plugs
  • Set the engine to top-dead-center (TDC)
  • Remove the valve cover
  • Remove the timing tensioner
  • Remove the camshafts
  • Access the shims as needed
  • Install the camshafts
  • Set the engine timing
  • Install the valve cover
  • Install the spark plugs
1. Remove the spark plugs:
Make sure each plug wire is labeled as to the cylinder it serves. Grasp the spark plug resistor cap and pull upward while turning, to remove:
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Using a 5/8" spark-plug socket, remove each spark plug:
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2. Remove side cover and set to top-dead-center (TDC):
Using an 8mm socket, remove the four bolts securing the side cover in place. Remove the side cover and sit aside:
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Using a 14mm wrench, rotate the engine counter-clockwise until the "T" mark on the rotor aligns with the mark on the pickup sensor:
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3. Remove the valve cover:
Using a 4mm hex-head (Allen head) socket, remove the 8 bolts securing the valve cover to the cylinder head. Note: Remove these bolts in a criss-cross pattern, 1/4 turn at a time, to prevent damage to the valve cover.
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There are small rubber grommets between the valvecover bolts and the valve cover. Pull these out and keep them with the bolts to prevent them from being lost. They are expensive; $9 each.
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In preparation for removing the valve cover, use zip-ties to secure the throttle cable and spark plug wires well out of the way:
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Lift the valve cover off of the cylinder head and place in a plastic bag to keep clean. Sit it aside. Note: If the VC does not want to come loose, gently tap on it using a rubber mallet to break the seal of the gasket.

4. Loosen the bolts securing the gear to the camshaft:
Using a 10mm socket, loosen the two bolts which hold each timing gear to the camshaft. Loosen them slightly but do not remove them.


5. Remove the cam chain tensioner:
With the valve cover removed, you will have access to the valvetrain. In preparation for removing the cams, the engine was placed at TDC for the #1 cylinder. To verify the #1 cylinder is at TDC, confirm that the cam lobes for the #1 cylinder point away from each other as shown:
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Using a 14mm socket, remove the bolt securing the timing tensioner adjustment spring:
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Behind the bolt, you will find a copper washer and two springs. Ensure both springs came out and place them in a ziplock bag:
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Using a 5mm hex-head (Allen head) socket, remove the two bolts securing the timing tensioner to the engine. Withdraw the timing tensioner and note its orientation:
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Stuff a piece of paper towel into the tensioner hole to prevent debris getting into the engine:
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Note: Do not rotate the engine while the timing chain tensioner is removed. The engine should be left at top-dead-center during the duration.


6. Remove the camshafts:
The timing chain should now be loose enough that you can lift it off of the cam gears. Lift it upward and sit it aside:
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Using a 10mm socket, remove the 12 bolts securing the cam caps. Note: Remove these bolts in a criss-cross manner, a 1/4 turn at a time. This will prevent damage to the camshaft. Continue until all bolts are loose and then remove the cam caps and lift out the cam. Note the location that each cam cap and cam go and mark them with a sharpie so that they can be installed in the same location
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To prevent the timing chain from falling into the engine, secure it with a pair of zip ties. This way, if it does fall in, it'll be easily removed:
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You now have full access to the lifters and valve shims: Using a magnetic pickup tool, remove the lifter (as needed). Use a small flat-blade screwdriver to pop the shim free from the lifter. Noe that the shim size is usually marked on the underside of the shim.
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