Toyota Celica/Supra 1971-1985 Repair Guide

Rocker Arms

Print

REMOVAL & INSTALLATION



Except 5M-GE Engine

See Figures 1 and 2



Click image to see an enlarged view

Fig. Fig. 1: Rocker shaft bolt removal sequence-8R-C and 18R-C engines



Click image to see an enlarged view

Fig. Fig. 2: Rocker shaft bolt tightening sequence-8R-C and 18R-C engines

  1. Remove the rocker shaft assemblies, as detailed in the Cylinder Head portion of this section.
  2.  
  3. On the single rocker shaft engines (8R-C and 18R), remove the rocker shaft support attaching bolts (#2 in illustration) and the rocker shaft retaining screw (#3 in illustration). Slide the tension springs, rocker arms and supports off of the shafts.
  4.  

Make sure you keep the parts in order as they were removed from the shaft-this is very important.

  1. On the double rocker shaft engines, remove the rocker shaft assemblies. Remove the three retaining screws and slide the rocker supports, springs and rocker arms off of the shafts. Keep all parts in order;
  2.  

The shafts must be reassembled in the correct order.

  1. Assembly is in the opposite order of removal; make sure all components are reassembled in their original positions. Adjust the valves.
  2.  
  3. Check the oil level and top off if necessary.
  4.  

5M-GE Engine

See Figures 3, 4, 5 and 6



Click image to see an enlarged view

Fig. Fig. 3: Camshaft housing bolt removal sequence for 5M-GE engines-loosen the bolts gradually in three passes



Click image to see an enlarged view

Fig. Fig. 4: The lash adjuster is under the rocker arm on 5M-GE engines



Click image to see an enlarged view

Fig. Fig. 5: Before installing the camshaft housings, align the match hole of each No. 2 journal with the hole in the housing



Click image to see an enlarged view

Fig. Fig. 6: Camshaft housing bolt tightening sequence-5M-GE engines

  1. Remove the valve cover(s).
  2.  
  3. Remove the timing gears and timing belt assemblies.
  4.  
  5. Following the sequence shown, loosen the camshaft housing nuts and bolts in two passes. Remove the housings (with camshafts) from the cylinder head.
  6.  
  7. Remove the rocker arms, one at a time, from the head. As you remove each rocker, wipe it off and either tag it or mark it as to its proper location. It is critical that each rocker be re-installed in its correct location.
  8.  
  9. Remove each lash adjuster from the head (see Lash Adjusters Inspection below first), one at a time, and either mark or tag each one for correct installation later.
  10.  
  11. Check the oil level and top off if necessary.
  12.  

INSPECTION



Except 5M-GE Engine

See Figures 7 and 8



Click image to see an enlarged view

Fig. Fig. 7: Check the rocker arm shaft wear by wiggling the arm laterally on the shaft



Click image to see an enlarged view

Fig. Fig. 8: Using a micrometer, measure the shaft diameter, then check the rocker arm inner diameter; the difference is the oil clearance

The oil clearance between the rocker arm and shaft is measured in two steps. Measure the outside diameter of the rocker shaft with a micrometer. Measure the inside diameter of the rocker arms with a dial indicator. The difference between the rocker arm inner diameter and the shaft outer diameter is the oil clearance. Clearance specs are as follows:



8R-C-0.0012-0.015 in. (0.030-0.381mm)
 
18R-0.00067-0.00201 in. (0.017-0.051mm)
 
20R-0.0004-0.0020 in. (0.010-0.050mm)
 
22R and 22R-EC-0.0031 in. (0.078mm)
 
4M-E and 5M-E-0.0005-0.0013 in. (0.0127-0.0330mm)
 

If specs are not within these ranges, replace either the rocker shaft or rocker arm. Clearance can also be checked by moving the rocker arm laterally on the shaft when assembled. There should be little or no movement.

While disassembled, check the cam follower end (the flat end that contacts the camshaft) of the rocker arm for excess wear. The surface should be smooth and shiny. If excess wear is evident, check also the lobe of the camshaft, it may also be worn.

Reassemble the rocker shaft assemblies in the exact opposite order or removal. Accelerated camshaft wear and/or sloppy valve action will result if rocker arms are mixed and end up operating against the wrong cam lobes.

5M-GE Engine

Inspect the three contact areas of each rocker arm for pitting and/or extreme or unusual wear: the cup end, which works against the ball of the lash adjuster; the valve stem end; and the pad on top of the rocker which works against the lobe of the camshaft. Replace the rocker arm(s) if there is evidence of such wear.

 
label.common.footer.alt.autozoneLogo