Camshaft, Lifters and Push Rods: Testing and Inspection

Camshafts, Tappet and Shim Inspection

Cam Wear
Using a micrometer, measure cam height. If measured height is below its limit, replace camshaft.

Cam height "a"








Camshaft Runout
Set camshaft between two "V" blocks, and measure its runout by using a dial gauge. If measured runout exceeds the specified limit, replace camshaft.

Runout limit 0.03 mm (0.0012 in.)





Camshaft Journal Wear
Check camshaft journals and camshaft housings for pitting, scratches, wear or damage. If any malcondition is found, replace camshaft or cylinder head with housing. Never replace cylinder head without replacing housings.





Check clearance by using gauging plastic. Checking procedure is as follows.

1. Clean housings and camshaft journals.
2. Make sure that all tappets with shims are removed and install camshafts to cylinder head.
3. Place a piece of gauging plastic to full width of journal of camshaft (parallel to camshaft).
4. Install camshaft housing.
5. Tighten camshaft housing bolts in such order as indicated in figure a little at a time till they are tightened to specified torque.

NOTE: Do not rotate camshaft while gauging plastic is installed.

Tightening torque
Camshaft housing bolt a: Tighten 11 Nm (1.1 kgf-m, 8.0 ft. lbs.) by the specified procedure





6. Remove housing, and using scale (2) on gauging plastic envelop (1), measure gauging plastic width at its widest point.

Journal clearance








If measured camshaft journal clearance exceeds limit, measure journal (housing) bore and outside diameter of camshaft journal. Replace camshaft or cylinder head assembly whichever the difference from specification is greater.

Camshaft journal








Wear of Tappet and Shim
Check tappet and shim for pitting, scratches, or damage.
If any malcondition is found, replace.





Measure cylinder head bore and tappet outside diameter to determine cylinder head-to-tappet clearance. If clearance exceeds limit, replace tappet or cylinder head.

Cylinder head bore and tappet outside diameter








Oil Relief Valve
Check oil relief valve for clogging and ball for being stuck.