Expedition 4WD V8-281 4.6L SOHC (1998)
Camshaft: Testing and Inspection
Lobe
Lobe Lift
Check the lift of each camshaft lobe in consecutive order and make a note of the readings.
1. Remove the valve covers.
2. Remove the spark plugs.
3. Install Dial Indicator with Bracketry so that the rounded tip of the indicator is on top of the camshaft lobe and on the same plane as the Hydraulic
Lash Adjuster (HLA).
4. Rotate the crankshaft until the base circle of the camshaft lobe is reached.
5. Zero the Dial Indicator with Bracketry. Continue to rotate the crankshaft until the (A) high-lift point of the camshaft lobe is in the fully-raised
position (highest indicator reading).
6. To check the accuracy of the original indicator reading, continue to rotate the crankshaft until (B) base circle is reached. The indicator reading
should be zero. If a zero reading is not obtained' repeat Steps 1 through 6.
7. If total lift recorded on Dial Indicator with Bracketry is not within specifications; replace the camshaft.
NOTE: If the lift on any lobe is below the specified service limits, the camshaft roller followers operating on that camshaft must be replaced.
8. Remove Dial Indicator with Bracketry.
9. Install the spark plugs.
10. Install the valve covers.
Lobe Surface
Inspect camshaft lobes for pitting or damage in the active area. Minor pitting is acceptable outside the active area.
