Lobe Lift

Camshaft Lobe Lift, 3.0L (2V) Engine:

Camshaft Lobe Lift, 3.0L (4V) And 3.4L SHO Engine:

1. Check the lift of each lobe in consecutive order and make a note of the readings.
2. Remove valve covers.
3. Remove rocker arm seat bolts, rocker arm seat and rocker arm (3.0L (2V) engine only).
4. On 3.0L engines, make sure valve tappet is seated against camshaft. Install Dial Indicator with Bracketry 100-002 (TOOL-4201-C) or equivalent so the ball socket adapter of indicator is on top of valve tappet. The Cup Shaped Adapter 303-007 (TOOL-6565-AB) or equivalent will be on top of push rod and in same plane as valve tappet or push rod movement.
5. On 3.0L(V) and 3.4L SHO engines, install Dial Indicator with Bracketry 100-002 (TOOL-4201-C) or equivalent so that the rounded tip of the indicator is on top of camshaft lobe and on the same plane as valve tappet.
6. Remove spark plugs.
7. Connect an auxiliary starter switch in starting circuit. Crank engine with ignition switch in OFF position. Bump crankshaft over until valve tappet is on base circle of camshaft lobe. At this point, valve tappet will be in its lowest position. If checking during engine assembly, turn crankshaft using a socket wrench and/or ratchet.
8. Zero the dial indicator. Continue to rotate crankshaft slowly until valve tappet is in fully-raised position (highest indicator reading).

9. NOTE: If lift on any lobe is below specified service limits, camshaft and valve tappet operating on worn lobes must be replaced, as well as any flat valve tappet showing pitting or a worn or concave contact face. Roller valve tappets showing wear on roller or having damaged bearings must be replaced.

Compare total lift recorded on indicator with specifications.
10. To check accuracy of original indicator reading, continue to rotate crankshaft until indicator reads zero.
11. Remove dial indicator, adapter and auxiliary starter switch.

12. CAUTION: After installing rocker arms, do not rotate crankshaft until hydraulic valve tappets have had sufficient time to bleed down. Otherwise serious valve damage may result. Manually bleeding down will reduce waiting time.

Install rocker arm seats (if equipped), rocker arms and rocker arm seat bolts (if equipped).
13. Install valve covers.
14. Install spark plugs.