Timing Chain and Sprockets
REMOVAL & INSTALLATION
2.3L and 2.4L Engines
The following tools will be required to perform this procedure:
- Camshaft sprocket timing alignment pins - J 36008 or equivalent
- Camshaft sprocket wrench - J 39579 or equivalent
Fig. 1: View of the DOHC engine "timed position'' - 2.3L and 2.4L engines
Fig. 2: View of the SOHC engine "timed position'' - 2.3L engine
- Remove the timing chain guides. There are usually three.
- Raise and safely support the front of the vehicle.
- Make sure all of the slack is above the tensioner. Gently pry off timing chain tensioner spring retainer, then remove the spring.
NOTE: On the 2.3L engine two styles of tensioners are used. Early production engines will have a spring post and late production ones will not. Both styles are identical in operation and are interchangeable.
- Remove the timing chain tensioner shoe retainer.
- Make sure all the slack in the timing chain is above the tensioner assembly; remove the chain tensioner shoe. The timing chain must be disengaged from the wear grooves in the tensioner shoe in order to remove the shoe. Slide a suitable small prybar under the timing chain while pulling shoe outward.
- If difficulty is encountered while removing chain tensioner shoe, proceed as follows:
- Lower the vehicle.
- Hold the intake camshaft sprocket with a camshaft sprocket wrench - J 39579 or equivalent holding tool and remove the sprocket bolt and washer.
- Remove the washer from the bolt and re-thread the bolt back into the camshaft by hand. The bolt provides a surface to push against.
- Remove intake camshaft sprocket using a 3-jaw puller in the 3 relief holes in the sprocket.
NOTE: Do NOT try to pry the sprocket off the camshaft or damage to the sprocket or chain housing could occur.
- Unfasten the tensioner assembly attaching bolts, then remove the tensioner.
The tensioner piston is spring loaded and could fly out causing personal injury. Use care when removing.
- Matchmark the timing chain outer surface for reassembly purposes.
- If equipped, remove the chain housing to block stud, which is actually the timing chain tensioner shoe pivot.
- Remove the timing chain.
- Inspect the parts for wear, then replace if necessary. Some scoring of the timing chain shoe and guides is normal. Clean the old sealant off of the bolt with a wire brush. Clean the threaded hole in the camshaft with a round nylon bristle brush.
Failure to following installation procedures can result in severe engine damage.
- Install the intake camshaft sprocket onto the camshaft with the marked surface showing. Install the sprocket retaining bolt and washer. Use an adhesive compound 12345493 or equivalent on the bolt. Tighten the bolt to 52 ft. lbs. (70 Nm), while holding the sprocket with tool J-36013, J 39579 or equivalent, if removed.
- Install tool J 36800 or equivalent, through hole(s) in the camshaft sprocket(s) into the holes in the timing chain housing. This positions the camshafts for correct timing.
Fig. 3: Placing the camshaft sprockets onto the marked surface of the camshaft
- If the camshafts are out of position and must be rotated more than 1?8 turn in order to install the alignment dowel pins:
- The crankshaft must be rotated 90°clockwise off of TDC in order to give the valves adequate clearance to open.
- Once the camshafts are in position and the dowels installed, rotate the crankshaft COUNTERCLOCKWISE back to TDC.
NOTE: Do NOT rotate the crankshaft clockwise to TDC, or valve and piston damage could occur.
The side of the timing chain that was marked must be facing outward when installed.
- For DOHC engines only, install the timing chain over the exhaust camshaft sprocket, around the idler sprocket and around the crankshaft sprocket.
- Remove the alignment dowel pin from the intake (DOHC only) camshaft. Using dowel pin remover tool J 39579 or equivalent, rotate the intake (DOHC only) camshaft sprocket counterclockwise enough to slide the timing chain over the intake (DOHC only) camshaft sprocket. Release the camshaft sprocket wrench. The length of chain between the two camshaft sprockets will tighten. If properly timed, the intake camshaft alignment dowel pin should slide in easily. If the dowel pin does not fully index, the camshafts are not timed correctly and the procedure must be repeated.
Fig. 4: Place the timing chain over the exhaust camshaft and around the idler sprocket and around the crankshaft sprocketDOHwhat is the position for the timing chain gears. - 91063g31.gif
- Leave the alignment dowel pins installed.
- Raise and safely support the vehicle.
- With slack removed from chain between intake camshaft sprocket (camshaft sprocket for SOHC engines) and crankshaft sprocket, the timing marks on the crankshaft and the cylinder block should be aligned. If marks are not aligned, move the chain one tooth forward or rearward, remove the slack and recheck the marks.
- If equipped, tighten the chain housing to block stud. The stud is installed under the timing chain. Tighten to 19 ft. lbs. (26 Nm).
- For vehicles through 1991, reload timing chain tensioner assembly to its "zero'' position as follows:
- Assemble restraint cylinder, spring and nylon plug into plunger. Index slot in restraint cylinder with peg in plunger. While rotating the restraint cylinder clockwise, push the restraint cylinder into the plunger until it bottoms. Keep rotating the restraint cylinder clockwise but allow the spring to push it out of the plunger. The pin in the plunger will lock the restraint in the loaded position.
- Install tool J-36589 or equivalent, onto plunger assembly.
- Install plunger assembly into tensioner body with the long end toward the crankshaft when installed.
- For 1992-98 vehicles, reload timing chain tensioner assembly to its "zero'' position as follows:
- Form a keeper from a piece of heavy gauge wire. See the accompanying figure.
- Apply slight force on the tensioner blade to compress the plunger.
- Insert a small prybar into the reset access hole, then pry the racket pawl away from the ratchet teeth while forcing the plunger completely in the hole.
- Install the keeper between the access hole and the blade.
Fig. 5: View of reloading the timing chain twhat is the position for the timing chain gears. - 86883177.gifembly to its "zero'' position - 1992-98 vehicles
- Install the tensioner assembly to the chain housing. Recheck the plunger assembly installation. It is correctly installed when the long end is toward the crankshaft.
- Install and tighten timing chain tensioner bolts. Tighten to 89 inch lbs. (10 Nm).
- Install the tensioner shoe and tensioner shoe retainer. Remove the special tool J-36589, then squeeze the plunger assembly into the tensioner body to unload the plunger assembly.
- Lower vehicle enough to reach and remove the alignment dowel pins.
- Rotate crankshaft clockwise (normal rotation) two full rotations. Align the crankshaft keyway with the mark on the cylinder block, then reinstall the alignment dowel pins. The pins will slide in easily if the engine is timed correctly.
If the engine is not correctly timed, severe engine damage could occur.
- Install the timing chain guides and, if equipped, the crankshaft oil slinger.
- Install the timing chain front cover. For details, please refer to the procedure located in this section.
- Connect the negative battery cable, then start the engine and check for oil leaks.