Repair 7

The timing chain in an internal combustion engine connects the crankshaft and camshaft. The timing chain ensures that the two shafts remain in sync with one another. Beginning in the mid 1980s, metal timing chains were widely replaced by rubberized timing belts or timing gears. An internal combustion engine will not run with a broken timing chain or belt. Timing chains are rarely known to break during an engines typical lifetime.

Under-tensioning

If a timing chain is not properly tensioned, it may develop slack, which can result in chain-slap and premature fatigue. Cracks in the chain may develop, resulting in failure.

Over-tensioning

An overly tight timing chain is placed under excessive stress. The added tension increases friction and heat within the moving parts of the chain that can result in early failure.

Engine Seizure

Situations such as an engine overheating or running out of oil can cause a piston to seize within the cylinder. If this happens while the engine is running at a high rpm, the sudden stop in rotation can cause a timing chain to fail.

When doing car repairs on engines, a chain hoist is often needed. It allows you to take the engine out of the car and suspend it, so you can easily access its inner parts. A chain hoist also makes it easier to lift heavier items in general. It can be difficult to mount a chain hoist in a garage or other building because it requires not only knowledge of how to put it up, but also an understanding of building structural integrity.

Instructions

1

Examine the area you want to use as the main support for the chain hoist. This should be a major support for the building as a whole and ideally a metal girder or support. It has to be able to hold several hundred pounds without putting it under too much stress. The last thing you want is for the beam to break or bend while working on the engine.

2

Place a ladder under the support beam for the hoist and throw the lifting sling over the beam. This is what will help lift the hoist to the proper height. Take out the shackle bolt and run it through the loops from the lifting sling and place back in the shackle.

3

Rest the eye loops of the sling on the shackle bolt by rotating the shackle and open the safety lock on the hoist hook located near the chain hoist. This allows for the movement of the chain into its proper position and height.

4

Open the hook of the hoist and slide it into the shackle and close the safety lock, so the chain will securely hang from the shackle. If the lock is not closed, the chain can slip when it lifts a load, causing injury. The hoist is now securely mounted to its main support and ready to be used.

The 1986 Toyota Pickup belongs to the fourth generation of this series which was in production from 1983 to 1988. The most common engine for this vehicle is a four-cylinder 2.4-liter engine. The 1986 Toyota pickup uses a timing chain to drive the camshaft with the crankshaft. The timing chain may require replacement, although it can last for the lifetime of the vehicle. The most critical aspect of the timing chain replacement is keeping the timing marks aligned during the procedure.

Instructions

1

Disconnect the alternator and oil pan with a socket wrench. Remove the cooling fan with the water pump still attached. Disconnect the securing bolt for the crankshaft pulley and pull the crankshaft pulley from the crankshaft with a suitable gear puller.

2

Detach the water bypass hose to access the timing chain cover. Disconnect the adjusting bar for the cooling fan belt with a socket wrench. Remove the water outlet pipe for the heater.

3

Remove the mounting bolts for the timing chain cover with a socket wrench, and detach the cover. Separate the timing chain from the crankshaft damper. Remove the timing chain and camshaft sprocket from the camshaft. Remove the crankshaft sprocket and oil pump drive from the crankshaft with a suitable gear puller.

4

Turn the crankshaft clockwise with a wrench until the crankshaft key aligns with the timing mark on the crankcase. Align the key way on the crankshaft sprocket with the key on the crankshaft and mount the sprocket to the crankshaft.

5

Mount the new timing chain to the crankshaft sprocket so that the single bright link on the chain aligns with the timing mark on the crankshaft sprocket. Mount the timing chain to the camshaft sprocket so that the timing mark on the sprocket is between the pair of bright links on the timing chain.

6

Place the drive spline for the oil pump over the key on the crankshaft and mount the gasket for the timing chain cover to the front of the engine block. Turn the camshaft sprocket counterclockwise with a wrench to take up the slack on the timing chain.

7

Replace the cover for the timing chain. Tighten the 8-mm mounting bolts to 9 foot-pounds with a torque wrench and tighten the 10-mm bolts to 29 foot-pounds. Apply a thin layer of gasket sealer to the gaskets for the oil pan and timing chain cover.

8

Connect the adjusting bar for the cooling fan belt, and tighten its mounting bolts to 9 foot-pounds with a torque wrench. Attach the water outlet pipe for the heater and the water bypass pipe.

9

Mount the crankshaft pulley to the crankshaft and tighten its mounting bolt with a socket wrench. Attach the water pump and air conditioning compressor. Connect the oil pan and alternator.

The timing chain keeps parts within your engine in sync by shutting and opening valves at their correct times. If you experience problems with your timing chain, knowing the right procedure for replacing it is valuable information to have.

Significance

Timing chain problems can lead to other serious engine issues. Pistons can be damaged as a result of a broken timing chain. You are also at risk of bending valves if you prolong your timing chain replacement.

Identification

There are several things that you can look for to identify timing chain problems. Strange engine noises proceeding from the front of the engine is a great indicator. A rattling sound as you increase and lower speeds often suggests that your timing chain is failing.

Procedure

To replace your timing chain, several parts will need to be removed first, such as fan belts and pulleys. Timing covers should also be removed and inspected. When replacing the timing chain, the tensioner and sprockets should be replaced with it as well.

The Ford Focus is a compact car that Ford has manufactured since 2000 for the United States. It has either a 2.0-liter or 2.3-liter engine with a double overhead camshaft. Some versions of the Focus use a timing chain to turn the camshafts with the crankshaft. The procedure for replacing the timing chain is generally the same, although some models of the Ford Focus also require you to remove the camshaft sprockets.

Instructions

1

Disconnect the front cover from the engine with a socket wrench. Compress the tension rod for the timing chain to align the hole in the tensioner housing with the hole in the tensioner rod. Place the end of a paperclip into the holes to keep the tensioner rod temporarily in place.

2

Remove the mounting bolts for the timing chain tensioner with a socket wrench and disconnect the tensioner from the crankcase. Disconnect the right guide for the timing chain, and detach the timing chain from the sprockets. Disconnect the left guide for the timing chain.

3

Attach a holding tool to the flats of the camshaft to hold it in place. Disconnect the mounting bolts for the camshaft sprockets with a socket wrench, and remove the sprockets from the camshafts. Remove the holding tool from the camshaft. Mount the camshaft sprockets to the camshaft, and fasten the mounting bolts by hand. Perform this step only if you need to remove the camshaft sprockets to install the new timing chain.

4

Mount the left guide for the timing chain, and tighten its mounting bolts to 89 inch-pounds with a torque wrench. Mount the timing chain to the crankshaft sprocket and camshaft sprockets. Connect the right guide for the timing chain, and tighten its mounting bolts to 89 inch-pounds.

5

Install the tensioner for the timing chain, and fasten its mounting bolts by hand. Pull the paper clip from the tensioner housing to apply tension to the timing chain. Tighten the mounting bolts for the tensioner to 89 inch-pounds with a torque wrench.

6

Attach the holding tool to the flats on the camshaft to hold the camshaft in place. Tighten the mounting bolts for the camshaft sprocket to 53 foot-pounds with a torque wrench. Perform this step only if you removed the camshaft sprockets in step three.

7

Attach the front cover to the engine with a socket wrench.