Toyota Celica/Supra 1971-1985 Repair Guide

Camshaft and Bearings

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REMOVAL & INSTALLATION



Except 5M-GE Engine
  1. Perform the Cylinder Head Removal procedure (for your engine) far enough to gain access to the camshaft bearing cap bolts. If you are going to remove the head anyway, remove the cam after removing the cylinder head.
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  3. Prior to removing the camshaft, measure its end-play with a feeler gauge. The end-play limit is 0.0098 inch (0.248mm) for the 8R-C, 18R-C, 20R and 22R engines; 0.01 inch (0.254mm) for the 4M-E and 5M-E engines. If the end-play is beyond this, replace the head.
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  5. Use a 12mm wrench to remove the bearing cap bolts. Remove the caps. Keep them in order, or mark them.
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  7. Measure the bearing oil clearance by placing a piece of Plastigage® on each journal. Replace the caps and tighten their bolts to 13-16 ft. lbs. (17-22 Nm).
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  9. Remove the caps and measure each piece of Plastigage®. If the clearance is greater than 0.004 inch (0.101mm), replace the head and cam.
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  11. Lift the camshaft out of the head.
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To install:
  1. Coat all of the camshaft bearing journals with engine oil.
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  3. Lay the camshaft in the head.
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  5. Install the bearing caps in numerical order with their arrows pointing forward (toward the front of the engine).
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  7. Install the cap bolts and tighten them to 13-16 ft. lbs. (17-21 Nm).
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  9. Complete the cylinder head installation procedure as previously outlined.
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5M-GE Engine
  1. Follow Steps 1-3 of the 5M-GE Rocker Arm Removal procedure, removing the camshaft housing (with cams) from the cylinder head.
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  3. Before removing the camshafts check camshaft end-play using a dial indicator set on the bench at one end of the front end of the camshaft. If this instrument is not available to you, take the housings to a reputable machine ship. Standard clearance is 0.0020-0.0098 inch (0.0508-0.248mm). If clearance is greater than this specification, the camshaft and/or cam housing must be replaced.
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  5. Remove the camshaft housing rear covers. Squirt clean oil down around the cam journals in the housing, to lubricate the lobes, oil seals and bearing as the cam is removed. Begin to pull the camshaft out of the back of the housing slowly, turning it as you pull. Remove the cam completely.
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  7. To install, lubricate the entire camshaft with clean oil. Insert the cam into the housing from the back, and slowly turn it as you push it into the housing. Install new O-rings in the housing end covers.
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CAMSHAFT INSPECTION



See Figures 1 through 8



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Fig. Fig. 1: Use a flat feeler gauge to measure the camshaft end-play



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Fig. Fig. 2: Use a piece of Plastigage® to measure the camshaft bearing clearance



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Fig. Fig. 3: Number or mark the camshaft bearing for later installation



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Fig. Fig. 4: Measure the camshaft end-play with a dial indicator-5M-GE engine shown



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Fig. Fig. 5: Slowly turn the camshaft as you remove it from the back of the housing



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Fig. Fig. 6: Measure the lobe height (shown) and journal diameter with a micrometer



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Fig. Fig. 7: The camshaft run-out must be measured with a dial indicator



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Fig. Fig. 8: Use an inside micrometer to measure the camshaft housing bore diameter

A dial indicator, micrometer and inside micrometer are all needed to properly measure the camshaft and camshaft housing. If these instruments are available to you, proceed; if they are not available, have the parts checked at a reputable machine shop. Camshaft specifications are included in a chart in this section.

  1. Using the micrometer, measure the height of each cam lobe. If a lobe height is less than the minimum specified, the lobe is worn and the camshaft must be replaced. Minimum intake and exhaust lobe heights are as follows:

    8R-C-1.721 inch (43.71mm) Intake; 1.724 inch (43.78mm) Exhaust
     
    18R-1.7206 inch (43.70mm) Intake; 1.7245 inch (43.80mm) Exhaust
     
    20R-1.6783-1.6819 inch (42.62-42.72mm) Intake; 1.6806-1.6841 inch (42.68-42.77mm) Exhaust
     
    22R and 22R-EC-1.6783-1.6819 inch (42.62-42.72mm) Intake; 1.6807-1.6842 inch (40.84-42.77mm) Exhaust
     
    4M-E-1.6797-1.6822 inch (42.66-42.72mm) Intake; 1.664-1.666 inch (42.26-42.31mm) Exhaust
     
    5M-E-1.6961 inch (43.08mm) Intake; 1.6988 inch (43.14mm) Exhaust
     
    5M-GE-1.3963 inch (35.466mm) Intake; 1.3963 inch (35.466mm) Exhaust
     

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  3. Place the camshaft in V-blocks and measure its run-out at the center journal with a dial indicator. On all but the 4M-E, 5M-E and 5M-GE engines, replace the camshaft if run-out exceeds 0.008 inch (0.203mm). On 4M-E and 5M-E engines, replace the camshaft if run-out exceeds 0.002 inch (0.05mm). On 5M-GE engines, the limit is 0.0016 inch (0.040mm).
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  5. Using the micrometer, measure journal diameter, jot down the readings and compare the readings with those listed in the Camshaft Specifications chart. Measure the housing bore inside diameter with the inside micrometer, and jot down the measurements. Subtract the journal diameter measurement from the housing bore measurement. If the clearance is greater than the maximum listed under Bearing Clearance in the chart, replace the camshaft and/or the housing.
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