Camshaft Inspection

NOTE: Do not rotate the camshaft during inspection.

1.Remove the intake camshaft gear and exhaust camshaft gear.

2.Remove four bolts securing the lower camshaft holder, then remove the lower camshaft holder and rocker arm/hydraulic tappet assembles.

3.Put the lower camshaft holder, camshafts, and upper camshaft holders on the cylinder head, then tighten the bolts in sequence to the specified torque.

Specified Torque 
8 mm Bolts: 22 N·m (2.2 kgf·m, 16 lbf·ft) 
6 mm Bolts: 12 N·m (1.2 kgf·m, 8.7 lbf·ft) 
6 mm Bolts: (21), (22), (23) 

 

4.Seat the camshaft by pushing it away from the camshaft pulley end of the cylinder head.

5.Zero the dial indicator against the end of the camshaft, then push the camshaft back and forth and read the end play. If the end play is beyond the service limit, replace the cylinder head and recheck. If it is still beyond the service limit, replace the camshaft.

Camshaft End Play 
Standard (New): 0.05-0.15 mm
(0.002-0.006 in.)
 
Service Limit: 0.16 mm (0.0063 in.) 

 

6.Unscrew the camshaft holder bolts two turns at a time, in a crisscross pattern. Then remove the upper camshaft holders from the lower camshaft holder.

7.Lift the camshafts out of the cylinder head, wipe them clean, then inspect the lift ramps. Replace the camshaft if any lobes are pitted, scored, or excessively worn.

8.Clean the camshaft journal surfaces in the lower camshaft holder, then set the camshafts back in place. Place a plastigage strip across each journal.

9.Install the upper camshaft holders, then tighten the bolts to the specified torque as shown in 3.

10.Remove the upper camshaft holders. Measure the widest portion of plastigage on each journal.

  • If the camshaft-to-holder clearance is within limits, go to 12.
  • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has been replaced, replace the cylinder head.
  • If the camshaft-to-holder clearance is beyond the service limit and the camshaft has not been replaced, go to 11.

Camshaft-to-Holder Oil Clearance 
Standard (New):  
No. 1 Journal: 0.0012-0.0027 mm (0.00005-0.00011 in.) 
No. 2, 3, 4, 5 Journals: 0.0020-0.0035 mm (0.00008-0.00014 in.) 
Service Limit:  
No. 1 Journal: 0.08 mm (0.003 in.) 
No. 2, 3, 4, 5 Journals: 0.10 mm (0.004 in.) 

 

11.Check the total runout with the camshaft supported on V-blocks.

  • If the total runout of the camshaft is within the service limit, replace the cylinder head.
  • If the total runout is beyond the service limit, replace the camshaft and recheck the camshaft-to-holder oil clearance. If the oil clearance is still beyond the service limit, replace the cylinder head.

Camshaft Total Runout 
Standard (New): 0.03 mm (0.001 in.) max. 
Service Limit: 0.04 mm (0.002 in.) 

 

12.Measure cam lobe height.

Cam Lobe Height Standard (New) 
Intake A: 36.433 mm (1.4462 in.) 
Intake B: 35.362 mm (1.3922 in.) 
Exhaust: 35.539 mm (1.3992 in.)