全车配件

常用配件

配件专家

维修专家

When replacing a pressed-fit camshaft gear, use a puller to remove it from the cam.

• Disconnect the negative battery cable.
• Remove the covers protecting the camshaft drive gears.
• Check for proper alignment of the timing marks on the timing gears.
• Remove the timing gears according to the service manual.
• Clean the timing gears.
• Inspect the gears for wear or cracks, and replace necessary parts.
• After replacing any worn or damaged gears and drives, set the timing marks according to the service manual.
• Rotate the engine through two complete rotations of the crankshaft. Check to see if the timing marks on the gears are still in proper alignment.
• Reinstall all covers removed for access.
• Reconnect the negative battery cable and start the engine.
• Set the ignition timing to the manufacturer's specifications.

When reinstalling the gear, take care that the cam does not move to the rear; it could knock loose the core plug in the rear of the block or chip cam lobes on neighboring lifters.

• The rear of the cam gear must be supported while the cam is pressed from its center.
• After the new cam gear is pressed on, end play is checked with a feeler gauge.
  
  
  Checking the clearance behind the thrust plate to determine camshaft end play. Courtesy of Federal Motors Corporation, Service Technology Group.
  
• The clearance between a cam thrust plate and the sprocket or gear varies from 0.0015" to 0.005".
• If a spacer is used, it must be from 0.0015" to 0.005" thicker than the thrust plate.
• The cam will press against the spacer, which fits inside the thrust plate hole, controlling end thrust.
• In some cases, adjustment is made by replacing the thrust plate.
• Some engines limit the end play of the camshaft through the use of a cam button.
• A nylon button or torrington bearing sets on a spring and is installed between the camshaft timing gear and the timing chain cover.
• Aluminum gears can be heated for easier installation.