### Timing Chain, Gears and Tensioner

#### REMOVAL & INSTALLATION

##### 200SX (Z Series)

1. Before beginning any disassembly procedures, position the No. 1 piston at TDC on the compression stroke.
2. 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.
3. 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.
4. 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
5. 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.
6. Using a two armed gear puller, remove the crankshaft sprocket assembly.

   To install:

7. 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.

   NOTE: 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.

8. 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.

   Fig. 1: Removing the camshaft sprocket

   Fig. 2: Tensioner and chain guide removal

   Fig. 3: Crankshaft sprocket removal

   Fig. 4: Timing chain and sprocket alignment — Z series engine

   Fig. 5: Use the No. 2 mark and hole to align camshaft — Z series engine