REMOVAL & INSTALLATION
200SX (Z Series)
See Figures 1, 2, 3, 4 and 5
- Before beginning any disassembly procedures, position the No. 1 piston at TDC on the compression stroke.
- Remove the front cover as previously outlined. Remove the camshaft cover and remove the fuel pump if it runs off a cam lobe in front of the camshaft sprocket.
- With the No. 1 piston at TDC, the timing marks in the camshaft sprocket and the timing chain should be visible. Mark both of them with paint. Also mark the relationship of the camshaft sprocket to the camshaft. At this point you will notice that there are three sets of timing marks and locating holes in the sprocket. They are for making adjustments to compensate for timing chain stretch. See the following "Timing Chain Adjustment" for more details.
- With the timing marks on the cam sprocket clearly marked, locate and mark the timing marks on the crankshaft sprocket. Also mark the chain timing mark. Of course, if the chain is not to be re-used, marking it is useless
- Unbolt the camshaft sprocket and remove the sprocket along with the chain. As you remove the chain, hold it where the chain tensioner contacts it. When the chain is removed, the tensioner is going to come apart. Hold on to it and you won't lose any of the parts. There is no need to remove the chain guide unless it is being replaced.
- Using a two armed gear puller, remove the crankshaft sprocket assembly.
- Install the timing chain and the camshaft sprocket together after first positioning the chain over the crankshaft sprocket. Position the sprocket so that the marks made earlier line up. This is assuming that the engine has not been disturbed. The camshaft and crankshaft keys should both be pointed upward. If a new chain and/or gear is being installed, position the sprocket so that the timing marks on the chain align with the marks on the crankshaft sprocket and the camshaft sprocket (with both keys pointing up). The marks are on the right hand side of the sprockets as you face the engine. The L18 has 42 pins between the mating marks of the chain and sprockets when the chain is installed correctly. The L20B has 44 pins. The 1977-78 L24 engine used in the 810 has 42 pins between timing marks. The L24 (1979-84), Z20E and Z20S engines do not use the pin counting method for finding correct valve timing. Instead, position the key in the crankshaft sprocket so that it is pointing upward and install the cam
shaft sprocket on the camshaft with its dowel pin at the top using the No. 2 (No. 1 on the L24) mounting hole and timing mark. The painted links of the chain should be on the right hand side of the sprockets as you face the engine. See the illustration.
The factory manual refers to the pins you are to count in the L-series engines as links, but in America, this is not correct. Count the pins. There are two pins per link. This is an important step. If you do not get the exact number of pins between the timing marks, valve timing will be incorrect and the engine will either not run at all, in which case you may stand the chance of bending the valves, or the engine will run very bad.
- Install the chain tensioner and the front cover assembly.
If timing chain assembly uses chain guides these guides do not have to be removed to replace the timing chain. Check the timing chain for cracks and excessive wear.
TIMING CHAIN ADJUSTMENT
See Figure 6
When the timing chain stretches excessively, the valve timing will be adversely affected. There are three sets of holes and timing marks on the camshaft sprocket.
If the stretch of the chain roller links is excessive, adjust the camshaft sprocket location by transferring the set position of the camshaft sprocket from the factory position of No. 1 or No. 2 to one of the other positions as follows:
- Turn the crankshaft until the No. 1 piston is at TDC on the compression stroke. Examine whether the camshaft sprocket location notch is to the left of the oblong groove on the camshaft retaining plate. If the notch in the sprocket is to the left of the groove in the retaining plate, then the chain is stretched and needs adjusting.
- Remove the camshaft sprocket together with the chain and reinstall the sprocket and chain with the locating dowel on the camshaft inserted into either the No. 2 or 3 hole of the sprocket. The timing mark on the timing chain must be aligned with the mark on the sprocket. The amount of modification is 4° of crankshaft rotation for each mark.
- Recheck the valve timing as outlined in Step 1. The notch in the sprocket should be to the right of the groove in the camshaft retaining plate.
- If and when the notch cannot be brought to the right of the groove, the timing chain is worn beyond repair and must be replaced.
See Figures 7, 8, 9, 10, 11, 12 and 13
- Disconnect the negative battery cable.
- Set the No. 1 piston at TDC of the compression stroke.
- Remove the front cover.
- If necessary, define the timing marks with chalk or paint to ensure proper alignment.
- Hold the camshaft sprocket stationary with a spanner wrench or similar tool and remove the camshaft sprocket bolt.
- Remove chain tensioner.
- Remove the chain guides.
- Remove the timing chain.
- Remove the sprocket oil slinger, oil pump drive gear and crankshaft gear.
- Install the crankshaft sprocket, oil pump drive gear and oil slinger onto the end of the crankshaft. Make sure the crankshaft sprocket timing marks face toward the front.
- Install the camshaft sprocket, bolt and washer. The alignment mark must face towards the front. Tighten the bolt just enough to hold the sprocket in place.
- Verify that the No. 1 piston is at TDC of the compression stroke. The crankshaft key-ways should be at the 12 o'clock position.
- Install the timing chain by aligning the marks on the chain with the marks on the crankshaft and camshaft sprockets. Torque the camshaft sprocket bolt to 87116 ft. lbs. (118157 Nm) once the timing chain is in place and aligned.
- Install the chain tensioner and chain guide.
- Install the front cover.
- Connect the negative battery cable.
See Figures 14 and 15
- Release the fuel system pressure.
- Disconnect the negative battery cable and drain the cooling system. Drain engine oil.
- Remove the cylinder head assembly.
- Remove the oil pan.
- Remove the oil strainer, crankshaft pulley.
- Remove the front cover assembly.
- Remove the lower timing chain tensioner, tension arm, lower timing chain guide.
- Remove the lower timing chain and idler sprocket.
- Check all components for wear. Replace as necessary. Clean all mating surfaces and replace the cylinder head gasket.
- Install crankshaft sprocket. Make sure that mating marks of crankshaft sprocket face front of the engine.
- Rotate crankshaft so that No. 1 piston is set a TDC position.
- Install idler sprocket and lower timing chain.
- Install chain tension arm, chain guide and lower timing chain tensioner.
- Install front cover assembly.
- Install crankshaft pulley, oil strainer and oil pan.
- Install the cylinder head assembly.
- Install all remaining components in reverse order of removal.
- Connect the negative battery cable. Refill all fluid levels. Road test the vehicle for proper operation.