REMOVAL & INSTALLATION
3A and 3A-C Engines
See Figures 1 through 6
- Remove the valve cover as described previously.
- Loosen the rocker support bolts, in three steps, using the proper sequence.
- Remove the bolts and remove the rocker assembly from the head. Inspect the valve contacting surfaces for wear. Inspect the rocker-to-shaft clearance by wiggling the rocker on the shaft. There should be virtually no play; any noticeable motion requires replacement of the rocker arms and/or the shaft.
- Disassemble the rockers from the shaft. Check the contact surfaces for signs of visible wear or scoring.
- Using either an inside micrometer or a dial indicator, measure the inside diameter of the rocker arm. Using a regular micrometer, measure the diameter of the shaft. Maximum allowable difference (oil clearance) between the two measurements is 0.0024 in. (0.06mm).
- After replacing any needed parts, loosen the adjusting screw lock nuts.
- The rocker shaft has oil holes in it. When assembling the rockers onto the shaft, make sure the holes point (when viewed from the end of the shaft) at the 3, 6 and 9 o'clock positions.
Failure to observe this positioning will starve the rockers for oil, causing expensive and premature wear.
- Loosen the valve adjusting screw lock nuts then install the rocker assembly on the head. Tighten the retaining bolts in three steps using the correct sequence. Torque the bolts to 18 ft. lbs. (25 Nm) on the third pass.
- Adjust the valves using the procedures in Engine Performance & Tune-Up .
See Figures 7 through 15
- Remove the valve cover following the procedures and cautions described earlier.
- Loosen the camshaft bearing cap bolts, a little at a time, using the proper sequence.
Do not remove the distributor bearing cap.
- Remove the camshaft.
- Arrange the bearing caps in order, do not mix them!
- Loosen the rocker arm adjusting screw locknuts.
- While lifting the top of the spring, pry off the spring with a small prytool.
- Remove the rocker arms and arrange them in order. Check the contact surface for any signs of pitting or wear.
- Check that the adjusting screw is positioned as shown and install a new spring to the rocker arm.
- Using a small prytool, press the bottom lip of the spring until it fits into the groove on the rocker arm pivot.
Make sure the valve adjusting screw is in the rocker arm pivot.
- Pry the rocker spring clip onto the pivot. Pull the rocker arm up and down to check that there is spring tension and that the rocker does not rattle.
- Install the camshaft. Refer to the procedures later in this section.
- Adjust the valves as described in Engine Performance & Tune-Up .