Mazda 323/626/929/GLC/MX-6/RX-7 1978-1989

Camshaft and Bearings

Print

REMOVAL & INSTALLATION



GLC and 1979-82 626

Perform this operation on a cold engine only.


WARNING
Do not remove the camshaft sprocket from the timing chain. Be sure that the sprocket and chain relationship is not disturbed. Wire the timing chain and sprocket together, so that they will not fall into the front cover. Maintain tension on the chain to avoid loss of timing at the crankshaft sprocket.

  1. Remove the water pump (except GLC front wheel drive).
  2.  
  3. Rotate the crankshaft so that the No. 1 cylinder is at TDC.
  4.  
  5. Remove the distributor, as described earlier in this section.
  6.  
  7. Remove the rocker arm cover.
  8.  
  9. Release the tension on the timing chain by using an appropriate clamping tool (rear wheel drive models) or by removing the tensioner (front wheel drive GLC). Refer to the procedures earlier in this section.
  10.  
  11. Remove the cylinder head bolts using several passes in the reverse of the torque sequence (refer to the Cylinder Head Removal & Installation procedure, earlier in this section).
  12.  
  13. Remove the rocker arm assembly.
  14.  
  15. If so equipped, remove the nut, washer and distributor drive gear from the camshaft.
  16.  
  17. Remove the nut and washer securing the camshaft sprocket.
  18.  
  19. Remove the camshaft and inspect for wear, as described later in this section.
  20.  

To install:
  1. Position the camshaft in the cylinder head, and fasten the timing chain sprocket. Coat the bearing surfaces with engine oil.
  2.  
  3. If applicable, install the distributor drive gear, washer and nut on the camshaft.
  4.  
  5. Re-tension the timing chain, as described earlier in this section.
  6.  
  7. Check that the camshaft end-play is within specifications, and correct if necessary.
  8.  
  9. Install the rocker arm assembly, then tighten the cylinder head bolts in several stages, using the appropriate torquing sequence. Check and adjust the valves, as described in Engine Electrical .
  10.  
  11. Install the rocker arm cover with a new gasket.
  12.  
  13. Install the distributor, as described earlier in this section.
  14.  
  15. If applicable, install the water pump.
  16.  

1983-87 626-Except Diesel
  1. Loosen the alternator mounting bolts, release belt tension, and remove the alternator belt.
  2.  
  3. Remove the cylinder head cover and gasket, then remove the upper timing belt cover and gasket.
  4.  
  5. Using a wrench on the crankshaft pulley bolt, turn the engine in its normal direction of rotation until the camshaft pulley "A" mark aligns with the V-notch at the top of the front housing.
  6.  
  7. Loosen the tensioner lockbolt until it can be turned by hand.
  8.  
  9. Block the camshaft pulley from turning by putting a socket and extension (or prybar of some sort) through one of the holes in the pulley. Secure this "wedge" against one of the front housing bolts, while loosening the pulley's lockbolt.
  10.  
  11. Remove the pulley from the camshaft, being careful to maintain tension on the timing belt so it won't slip off the timing belt crankshaft pulley below.
  12.  

If the belt does not maintain sufficient contact with the timing belt pulley, you will have to remove the crankshaft pulley and realign the timing marks.

  1. Loosen the rocker assembly mounting bolts in several stages, following the proper sequence (refer to the Rocker Shafts Removal & Installation procedure, earlier in this section). Remove the rocker assembly (with the bolts intact), then remove the camshaft.
  2.  

To install:
  1. Before replacing or reinstalling the camshaft and related parts, check the bearing clearance, end-play, along with the cam and journal dimensions, as described later in this section.
  2.  
  3. Lubricate all parts thoroughly with clean engine oil and position the camshaft on the cylinder head with the pin in the front positioned at the top.
  4.  
  5. Lubricate the bearing surfaces and position the rocker assembly on the cylinder head. Torque the bolts in several stages to 13-19 ft. lbs. (18-26 Nm), following the appropriate sequence.
  6.  
  7. Raise the camshaft pulley into position at the front of the camshaft without losing the timing. To do this, maintain upward tension on the pulley while carefully levering the tensioner upward against spring tension. When the pulley is high enough, position it on the front of the camshaft so that the lockpin engages the hole in the pulley. Install and tighten the pulley lockbolt to 35-48 ft. lbs. (47-65 Nm), while keeping the pulley from turning, as described above.
  8.  
  9. Using a wrench on the crankshaft pulley bolt, turn the engine two revolutions in its normal direction. You can check that belt timing is correct by aligning the crankshaft pulley and oil pump body timing marks, then checking that the marks on the camshaft pulley and timing cover are still aligned. Torque the tensioner bolt to 28-38 ft. lbs. (38-51 Nm).
  10.  
  11. Check and adjust the valves, as described in Engine Electrical .
  12.  
  13. Install the timing belt cover, with a new gasket if necessary, and torque the bolts to 5-7 ft. lbs. (7-9 Nm).
  14.  
  15. Reinstall the cylinder head cover with a new gasket.
  16.  
  17. Install and properly tension the alternator belt.
  18.  

626 Diesel

See Figures 1, 2 and 3

To perform this procedure, you will need a 6mm hexagonal (Allen type) socket and a puller with bolts that screw into the threaded holes of the camshaft's front and rear pulleys. You will also need two M8 x 32mm x 45mm bolts to remove the rear pulley.

  1. Disconnect the negative battery cable. Remove the drive belts and right side splash shield.
  2.  
  3. Remove the cylinder head cover and gasket. Using a 6mm hexagonal socket, unfasten and remove the front portion of the crankshaft pulley.
  4.  
  5. Remove the rear timing belt cover. Turn the crankshaft until the rear camshaft pulley and rear seal plate timing marks align.
  6.  
  7. Loosen the lockbolt for the belt tensioner. Use a screwdriver to turn the tensioner and remove all tension from the belt. Hold the tensioner all the way in the released position, then tighten the tensioner lockbolt to hold it in this position.
  8.  
  9. Mark the timing belt for reinstallation in the same direction, then remove the belt.
  10.  
  11. Hold the camshaft with an open-end wrench installed on the flats located just behind the center bearing. Loosen the rear pulley lockbolt, but do not remove it. Install a puller by screwing its two outer bolts into the threaded holes of the pulley. When they are threaded in all the way, tighten the bolt at the center of the puller so that its inner end rests against the lockbolt. Continue turning the center bolt until the pulley comes free of the camshaft. Remove the puller and pulley, along with the key. Be sure to retain the key.
  12.  
  13. Install the two bolts described in the note above through the two holes in the injection pump drive pulley and into the rear seal plate. Then, unscrew the pulley lockbolt. After the lockbolt is removed, use a puller to remove the pulley from the injection pump driveshaft.
  14.  
  15. Remove both front timing belt covers and their gaskets.
  16.  
  17. Turn the crankshaft via the bolt at its center so the timing marks on the camshaft pulley and front seal plate align.
  18.  
  19. Loosen the lockbolt on the belt tensioner, push the tensioner to the left (so as to tighten the spring and loosen the belt), then hold it there as you retighten the lockbolt. Unbolt and remove the torque stop from in front of the timing belt.
  20.  
  21. Mark the timing belt for its direction of rotation, then remove the belt.
  22.  
  23. Turn the crankshaft 45 degrees clockwise from the timing mark on the front of the oil pump housing, as shown.
  24.  

Do not attempt to hammer the pulley or camshaft to remove the pulley.

  1. Hold the camshaft with an open-end wrench installed on the flats located just behind the center bearing. Loosen the front pulley lockbolt, but do not remove it. Then, install a puller by screwing its two outer bolts into the threaded holes in the pulley. When they are threaded in all the way, tighten the bolt at the center of the puller so its inner end rests against the lockbolt. Continue turning the center bolt until the pulley comes free of the camshaft. Remove the puller and pulley, along with the key. Be sure to retain the key.
  2.  
  3. To remove the timing belt crankshaft pulley, use a tire iron to hold the flywheel in place as you remove the lockbolt. The pulley should slide straight off the crankshaft. Make sure to retain both the washer and key.
  4.  
  5. Loosen the camshaft bearing cap nuts a little at a time, using several stages of the numbered order. Then, remove the camshaft front and rear bearing caps. Next, remove both the front and rear camshaft oil seals.
  6.  
  7. Use a small prytool and carefully pry the oil pump (front crankshaft) oil seal out of the oil pump.
  8.  
  9. Remove the tensioner lockbolts, springs, and tensioners from both the front and rear of the engine. Remove the lockbolts and remove both the front and rear seal plates.
  10.  
  11. Remove the attaching nuts and remaining camshaft bearing caps, then remove the camshaft.
  12.  

To install:
  1. Inspect the camshaft bearing surfaces and bearing clearances, then check the camshaft dimensions as described later in this section. Replace any worn parts. Thoroughly lubricate all bearing surfaces (saddles, caps, and cam journals), then carefully position the camshaft in the block.
  2.  



Click image to see an enlarged view

Fig. Fig. 1: After removing the timing belt, rotate the crankshaft 45° clockwise to guard against piston or valve damage



Click image to see an enlarged view

Fig. Fig. 2: Diesel engine camshaft caps must be loosened in the order shown



Click image to see an enlarged view

Fig. Fig. 3: Diesel engine camshaft caps must be tightened in the order shown


CAUTION
Install the camshaft so that the groove for the front pulley's key faces straight upward. Otherwise, the valve and pistons may be damaged when the caps are torqued!

  1. Install front and rear seal plates and their lockbolts. Coat the entire surfaces on which both the front and rear camshaft caps rest with a sealer. Then, install the camshaft caps and nuts. Tighten the nuts very slightly.
  2.  
  3. Install front and rear camshaft seals by hand. Note that the rear seal is slightly larger. Make sure you coat the seal lips with oil first.
  4.  
  5. Tighten the caps in three stages of the numbered order to 15-21 ft. lbs. (20-28 Nm). Oil its lips, then install a new oil pump oil seal around the crankshaft. Use a hammer and a 1.4 in. (35.5mm) diameter pipe to gently tap the oil pump seal into position. The oil pump seal's front edge should be aligned with the front edge of the oil pump body.
  6.  
  7. Use a 1.3 in. (33mm) or slightly smaller pipe to tap the front and rear camshaft seals into position. The front edge of the front seal should be aligned with the front edge of the cylinder head; the front edge of the rear seal should be aligned with the rear edge of the cylinder head.
  8.  
  9. The remaining steps of the installation procedure are the reverse of the removal procedure. Refer to timing belt removal and installation procedures to install and adjust the belts. If the camshaft has been replaced, adjust the valves before running the engine.
  10.  

323 Models
NON-TURBO
  1. Remove the cylinder head cover, as described previously in this section.
  2.  
  3. Remove the camshaft pulley after inserting a small prytool in one of the slots on the face of the pulley to hold it in place while loosening the bolt with a wrench. After removing the bolt, withdraw the pulley from the camshaft.
  4.  
  5. Remove the rocker shaft assembly, as described earlier in this section.
  6.  
  7. Unfasten the attaching bolt, then remove the camshaft thrust plate from the front bearing. Carefully pry the camshaft oil seal out of the front cylinder head bore with a small prytool. Be careful not to damage the bore or camshaft! Slide the camshaft out of the bearing bores in the head.
  8.  
  9. Inspect the camshaft bearing surfaces and bearing clearances, then check the camshaft dimensions as described later in this section. Replace any worn parts.
  10.  

To install:
  1. Thoroughly lubricate all bearing surfaces (bores and cam journals), then carefully slide the camshaft into position in the block.
  2.  
  3. Install the camshaft thrust plate and attaching bolt. Torque the thrust plate attaching bolt to 6-8 ft. lbs. (8-11 Nm).
  4.  
  5. Coat the outer bore of a new camshaft oil seal and the inner bore of the cylinder head with a thin coat of engine oil. With a piece of pipe approximately the diameter of the oil seal (but not larger), gently tap the seal straight into position around the front of the camshaft.
  6.  
  7. Install the camshaft pulley onto the dowel pin with the pin groove facing straight upward, then torque the camshaft pulley bolt to 36-45 ft. lbs. (49-61 Nm).
  8.  
  9. Install the rocker shaft assembly, as described previously in this section. Check and adjust the valve clearances.
  10.  
  11. Install the cylinder head cover with a new gasket, as described previously in this section.
  12.  

TURBO

See Figures 4 and 5

  1. Remove the cylinder head cover, as described previously in this section.
  2.  
  3. Engage the camshaft journal that is closest to the seal plate with an adjustable wrench to hold it stationary. Using a box wrench, loosen the camshaft pulley bolt. Remove the bolt and washer, then slide the camshaft pulley from the camshaft. The remaining camshaft pulley is removed in exactly the same manner.
  4.  
  5. Unbolt and remove the seal plate from the cylinder head. Gently insert the end of a suitable prying tool between the cylinder head and the camshaft oil seal, then remove the seal. Be careful not to damage the seal bore during removal. Remove the remaining oil seal in the same manner.
  6.  



Click image to see an enlarged view

Fig. Fig. 4: Cylinder head components-323 turbo



Click image to see an enlarged view

Fig. Fig. 5: Camshaft cap bolt tightening sequence-323 turbo

  1. Remove the camshaft cap retaining bolts in reverse of the tightening sequence and remove the caps. (Although the caps are numbered, it might be advisable to record fore and aft orientation for easier reference.)
  2.  
  3. Lift the intake and exhaust camshafts from the bearing saddles in the cylinder head. Clean the camshafts thoroughly with a lint-free rag and set the camshaft on V-blocks. Proceed to the inspection procedures, as described later in this section.
  4.  

To install:
  1. Coat the bearing, journal and lobe surfaces of the camshaft with clean engine oil. Gently place the camshafts into the cylinder head.
  2.  
  3. Apply a thin coat of oil to the camshaft oil seal bores and the lip of the new seals. Install the seals into the cylinder head using a hammer and socket or a length of pipe that closely approximates the diameter of the seal. Tap the seals evenly into the seal bores.
  4.  
  5. Wipe each cap with a clean rag. Locate the front camshaft cap and apply a thin coat of non-hardening sealant to the cap surface. Do not apply sealant to the bearing surface!
  6.  
  7. Install the camshaft caps in their original locations. Gradually torque the camshaft cap bolts in the proper sequence to 8-11 ft. lbs. (11-15 Nm).
  8.  
  9. Install the exhaust side camshaft pulley so that the E mark stamped on its face is aligned with the upper timing mark on the front housing. Similarly, install the intake side camshaft pulley so that the I mark is aligned with the upper timing mark on the front housing. Install the pulley bolts and washers. Hold the camshaft stationary as described earlier and torque the bolts to 36-45 ft. lbs. (49-61 Nm).
  10.  
  11. Install the cylinder head cover with a new gasket and seal washers, as described previously in this section.
  12.  

1988-89 626/MX-6
  1. Disconnect the negative battery cable.
  2.  
  3. Tag and disconnect the spark plug wires, then remove the spark plugs (for easier crankshaft rotation).
  4.  
  5. Remove the engine side cover and the accessory drive belts.
  6.  
  7. Unbolt the crankshaft pulley, then remove the upper and lower timing belt covers and gaskets. Remove the crankshaft pulley baffle plate and note how it is installed. The curved side should be facing out.
  8.  
  9. Engage the timing belt pulley's lockbolt with an appropriate size metric socket and breaker bar, then turn the crankshaft in its normal direction of rotation until the "arrowed" 1 mark on the camshaft is aligned with the mark on top of the front housing (see illustration). Unbolt and remove the tensioner, then disconnect the tensioner spring from its mount.
  10.  
  11. Remove the timing belt. If the old timing belt is to be reused, mark the direction of rotation, prior to removal.
  12.  
  13. Block the camshaft pulley from turning by putting a socket and extension (or prybar of some sort) through one of the holes in the pulley. Secure this "wedge" against one of the front housing bolts, while loosening the pulley's lockbolt and washer.
  14.  
  15. Remove the pulley from the camshaft.
  16.  
  17. Remove the cylinder head cover, as described earlier in this section.
  18.  
  19. Unfasten and remove the front and rear cylinder head housings, along with their gaskets.
  20.  
  21. Wipe all the camshaft journals with a clean lint-free rag. Before removing the rocker arm shafts, refer to the inspection procedures, later in this section, then check the camshaft end-play and journal oil clearances. These measurements will help you determine if the camshaft is acceptable for reinstallation or whether it should be replaced.
  22.  
  23. Loosen the rocker arm shaft bolts following the appropriate sequence, as described earlier in this section. Loosen each bolt gradually, in several stages, and remove along with the spacers. Mark the shafts based on which side of the head they are installed (intake or exhaust), and keep the components of each shaft in a separate plastic bag. Look at the amount of holes in both shafts to determine on what side they are installed. The intake shaft has twice the amount of holes as the exhaust side. The stepped ends of both shafts go toward the rear of the head.
  24.  

Do not remove the hydraulic lash adjusters, unless it is absolutely necessary to do so. The lash adjusters are sealed in the rocker arms by an O-ring. If this O-ring is disturbed or damaged, the lash adjusters may leak. If they are removed, make sure that new O-ring are installed and that the oil reservoirs in the rocker arms are filled with clean engine oil.

  1. The camshaft caps are marked with arrows that show the installation position. Note the direction of the arrows, so that they will be installed in the original positions. Remove the camshaft caps and lift the camshaft from the bearing saddles in the cylinder head. There are five camshaft caps, with No. 3 at the center. The No. 3 cap has a drilled oil passage from which it receives oil from the cylinder head. It must be reinstalled in its original position. Clean the shaft thoroughly and set the camshaft on V-blocks. Proceed to the inspection section.
  2.  

To install:
  1. Liberally coat all the camshaft bearing, journal and lobe surfaces with clean engine oil. Gently place the camshaft into the cylinder head. Rotate the camshaft until the dowel pin on the end of the shaft is facing straight up.
  2.  
  3. Install the camshaft caps so that the arrows are facing in the original direction. Make sure that the No. 3 cap is installed correctly.
  4.  
  5. Install the rocker arm shafts so that the stepped ends are facing the rear of the head. Install the rocker arm shaft retaining bolts and spacers. Torque the bolts gradually in the proper sequence to 13-20 ft. lbs. (18-27 Nm). When tightening the bolts, prevent the rocker arm and spacers from being pinched between the shaft and the camshaft cap.
  6.  
  7. Apply engine oil to a new oil seal and to the front housing bore, then press the seal in place.
  8.  
  9. Apply engine oil to the oil seal lip, then install the cylinder head front housing with a new gasket.
  10.  
  11. Install the cylinder head rear housing with a new gasket.
  12.  
  13. Attach the cylinder head cover with sealant and bolts, as described earlier in this section.
  14.  
  15. Install the timing belt tensioner and timing belt, as described earlier in this section. Install the crankshaft pulley baffle plate.
  16.  
  17. Install the timing belt covers, using new gaskets if necessary.
  18.  
  19. Position the crankshaft pulley, and torque the botls to 9-13 ft. lbs. (12-17 Nm).
  20.  
  21. Install and properly tension the accessory drive belts. Install the engine side cover.
  22.  
  23. Install the spark plugs and connect the plug wires.
  24.  
  25. Connect the negative battery cable.
  26.  

929

The following procedure applies to the camshaft in either cylinder bank.

  1. Rotate the engine so that the No. 1 piston is at TDC. Properly relieve the fuel system pressure, as described in Fuel System .
  2.  
  3. Disconnect the negative battery cable and drain the cooling system.
  4.  
  5. Tag and disconnect the spark plug wires, then remove all six spark plugs (to make crankshaft rotation easier).
  6.  
  7. Remove the fresh air duct, the cooling fan and radiator cowling. Remove the drive belts.
  8.  
  9. Remove the air conditioning compressor idler pulley. If necessary, unfasten the compressor and position it to the side.
  10.  
  11. Remove the crankshaft pulley and baffle plate. Remove the coolant bypass hose and the upper radiator hose.
  12.  
  13. Remove the timing belt cover assembly retaining bolts. Remove the left and right timing belt covers and gaskets. Turn the crankshaft to align the mating marks of the pulleys.
  14.  
  15. Remove the upper idler pulley. Remove the timing belt. If reusing the belt, be sure to mark the direction of rotation. Remove the timing belt auto tensioner.
  16.  
  17. Remove the cylinder head cover and gasket. If necessary, first remove/reposition any components which interfere.
  18.  
  19. Engage the camshaft pulley with a suitable spanner wrench type holding tool and loosen the retaining bolt. Remove the pulley from the end of the camshaft.
  20.  
  21. Loosen the rocker arm shaft retaining bolts in the sequence shown in Rocker Arm/Shaft Removal and Installation section described earlier in this section. Loosen the bolts gradually and in several stages. Remove the rocker arm and shaft assemblies.
  22.  

Do not remove the hydraulic lash adjusters, unless it is absolutely necessary to do so. The lash adjusters are sealed in the rocker arms by an O-ring. If this O-ring is disturbed or damaged, the lash adjusters may leak. If they are removed, make sure that new O-rings are installed and that the oil reservoirs in the rocker arms are filled with clean engine oil.

  1. Insert the blade of a small prytool between the camshaft oil seal and gently pry the seal from the cylinder head bore. Be careful not to damage the seal bore. Discard the seal and purchase a new one.
  2.  
  3. Before removing the camshaft thrust plate, proceed to the inspection section to measure the camshaft end-play. This will determine if the thrust plate or the camshaft have to be replaced.
  4.  
  5. Remove the thrust plate, then slowly and carefully withdraw the camshaft from the cylinder head. Clean off the lobe and journal surfaces, then proceed to the inspection section, which follows.
  6.  

The camshaft in the left cylinder bank fits into a distributor/oil pump drive gear. Since this drive gear engages both the distributor shaft and the oil pump driveshaft gear, you must also remove the necessary parts to disengage the gears, before the left camshaft can be removed.

To install:
  1. If applicable, apply sealant to the end of the distributor/oil pump drive gear which mates with the left camshaft, then fully seat the gear.
  2.  
  3. Apply a liberal coating of clean engine oil to the surfaces of the cam lobes, bearing and journal surfaces. Slowly and carefully insert the camshaft into the cylinder head. Install the camshaft thrust plate and torque the retaining bolt to 6-8 ft. lbs. (8-11 Nm).
  4.  
  5. Wipe down the surface of the seal bore with a clean rag and coat the lip of the new oil seal with clean engine oil. Install the seal into the cylinder head using a socket or a length of pipe (that closely approximates the diameter of the seal) as an installation tool. Tap the seal evenly into the seal bore.
  6.  
  7. Coat the surfaces of the rocker arm and the rocker arm shafts with clean engine oil. Install the rocker shafts in their original positions. The intake side shaft has twice as many oil holes as the exhaust side. Torque the rocker shaft bolts to 14-19 ft. lbs. (19-26 Nm) in several stages of the proper sequence. When tightening the rocker shaft bolts, makes sure the rocker arm shaft spring does not get pinched between the shaft and the mounting boss.
  8.  
  9. Align the camshaft so that its key points upward, then install the camshaft pulley. On the left cylinder bank, the L mark on the face of the pulley should be at the top, while on the right cylinder bank, the R mark should be at the top. Tighten the retaining bolt to 52-59 ft. lbs. (71-80 Nm).
  10.  
  11. Install the cylinder head cover with a new gasket and new seal washers.
  12.  
  13. If applicable, install the oil pump drive gear and gear cover, as well as the distributor spacer and distributor on the left cylinder head. Be sure to replace the O-rings with new ones and to lubricate the drive gears and O-rings with engine oil.
  14.  
  15. The remainder of the installation is the reverse of the removal procedure. Be sure to reload the timing belt tensioner and install the timing belt, as described earlier in this section.
  16.  
  17. Fill the cooling system to the proper level and reconnect the negative battery cable.
  18.  

INSPECTION



See Figures 6, 7, 8, 9 and 10

  1. Inspect the camshaft cam faces and bearing journals for roughness or obvious excessive wear. Measure the cam height with a micrometer, taking measurements at the outer edge of the cam on both sides. The surface of the cam must be clean to ensure accurate readings.
  2.  

Replace the camshaft if it is obviously worn/damaged, or if the cam height is worn beyond limits as listed in the "Camshaft Specifications Chart" in this section.

Click image to see an enlarged view

Fig. Fig. 6: Use a micrometer to measure camshaft journal diameter at the outer edge of each cam (as indicated by the numbers 1 and 2). Also take measurements 90 degrees apart to determine elliptical wear (as indicated by letters A and B)



Click image to see an enlarged view

Fig. Fig. 7: Checking camshaft run-out with a dial indicator



Click image to see an enlarged view

Fig. Fig. 8: Checking camshaft journal bearing oil clearances using Plastigage® inserts



Click image to see an enlarged view

Fig. Fig. 9: Measuring camshaft bore diameter to determine the camshaft journal oil clearance-1.6L non-turbo and 3.0L engines



Click image to see an enlarged view

Fig. Fig. 10: Checking camshaft end-play with a dial indicator

  1. Measure the camshaft bearing journals with a micrometer. The cam journals should also be measured at 90 degree angles to determine elliptical wear. Subtract the smaller reading from the larger. The limit is 0.002 in. (0.05mm) for all engines except the 3.0L. On the 3.0L engine, maximum out-of-round is 0.0012 in. (0.03mm).
  2.  

On 1.3L, 1.5L, 1.6L and 2.0L (Codes FE and RF) engines, the camshaft must be replaced if worn beyond limits. On 2.0L (Code MA) engines, the journals may be ground and undersize bearings may be installed.

  1. Mount the camshaft on metal V-blocks and check camshaft runout with a dial indicator, taking the measurement at the center bearing. The limit is 0.0012 in. (0.03mm).
  2.  
  3. Check the camshaft bearing clearances. This is done by installing Plastigage® or equivalent inserts, which will flatten out according to the bearing clearance when the camshaft bearing caps are torqued to specification. You can determine the clearance after removing the rocker assembly and inserts, then measuring the insert's dimensions. Be sure to follow the package directions.

    Torque rocker assembly bolts to 56-60 ft. lbs. (76-81 Nm) on all engines except the 2.0L (Codes FE and RF) and 2.2L. On the 2.0L engine, torque the assembly bolts to 13-19 ft. lbs. (18-26 Nm), and on the 2.2L engine, torque the bolts to 13-20 ft. lbs. (18-27 Nm). On 1.6L turbo engines, torque the camshaft caps to 8-11 ft. lbs. (11-15 Nm).
     
    Torque the diesel engine camshaft bearing caps to 15-20 ft. lbs. (20-27 Nm).
     
    Clearance should be 0.0007-0.0027 in. (0.018-0.069mm) for front and rear bearings, and 0.0011-0.0031 in. (0.03-0.08mm) for the center bearing on the 2.0L (Code MA) engines, which use bearing inserts. On the 1.5L engine, the clearance limit is 0.0059 in. (0.15mm). On the 1.6L turbo engine, the oil clearance for all journals is 0.0014-0.0032 in. (0.035-0.080mm). On the 2.0L gasoline and 2.2L engines, clearance should be 0.0014-0.0033 in. (0.035-0.084mm) on bearings 1 and 5 (at either end), and 0.0026-0.0045 in. (0.066-0.114mm) on bearings 2 and 4. On the 2.0L diesel engine, clearance should be 0.0014-0.0033 in. (0.035-0.084mm) for the front and rear bearings, and 0.0026-0.0045 in. (0.066-0.114mm) for the three center bearings.
     
    On the 1.6L non-turbo and 3.0L engines, you must measure the outside diameter of the cam journals, and use an inside diameter micrometer to measure the inside diameters of the bearing bores (these are integral with the cylinder head). Subtract the smaller figure from the larger to get the clearance. On the 1.6L engine, normal limits are 0.0014-0.0033 in. (0.035-0.085mm) for the front and rear bearings, and 0.0026-0.0045 in. (0.065-0.115mm) for the center bearings. The maximum allowable clearance is 0.0059 in. (0.15mm) for all bearings. On the 3.0L engine, normal limits are 0.0024-0.0035 in. (0.060-0.090mm) for the front and rear bearings, and 0.0031-0.0045 in. (0.080-0.115mm) for the center bearings. The maximum allowable clearance is 0.0059 in. (0.15mm) for all bearings.
     
    Except on the 2.0L (Code MA) engines (which have replaceable bearings), the cylinder head assembly and rocker assembly must be replaced if the camshaft is within limits, but the clearance is still excessive.
     

  4.  

  1. With the camshaft installed in the cylinder head, measure camshaft end-play by inserting a feeler gauge between the camshaft pulley surface and the surface of the thrust plate, or by mounting a dial indicator against the cylinder head, and pushing the camshaft along its axis. Although their standard ranges may vary slightly, the camshaft end-play wear limit is 0.008 in. (0.20mm) for all piston engines covered by this information. If clearance is excessive, replace the thrust plate.
  2.  

 
label.common.footer.alt.autozoneLogo