Toyota Pick-ups/Land Cruiser/4Runner 1970-1988

Timing Chain and Tensioner

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REMOVAL & INSTALLATION



See Figures 1 and 2

8R-C and 18R-C Engines
  1. Remove the cylinder head and timing chain cover as previously detailed.
  2.  
  3. Remove the timing chain (front) together with the camshaft drive sprocket.
  4.  
  5. Remove the crankshaft sprocket and oil pump jack shaft, complete with the pump jack shaft, complete with the pump drive chain (rear). Remove the chain vibration damper.
  6.  


CAUTION
Both timing chains are identical; tag them for proper identification during installation.

  1. Inspect the chains and sprockets for wear or damage. Clean the chains with solvent.
  2.  
  3. Use a vernier caliper to measure the amount of stretch of both chains. Measure any 17 links while pulling the chain which is being measured taut.
  4.  
  5. Repeat Step 5 at two other places on each chain. Replace either of the chains if any of the 17 link measurements exceed 147mm or if the difference between the minimum and maximum readings is more than 0.20mm, on any one chain.
  6.  
  7. Remove the plunger and spring from one of the chain tensioners. Inspect all of the parts of the tensioner for wear of damage. Fill it with oil and assemble it if it is not defective.
  8.  
  9. Repeat Step 7 for the other tensioner.
  10.  


CAUTION
Do not mix the parts of the two chain tensioners together.

To install:
  1. Position the No. 1 piston at TDC by having the crankshaft keyway point straight up (perpendicular to ) toward the cylinder head.
  2.  
  3. Align the oil pump jack shaft, with its keyway pointing straight up as well.
  4.  
  5. Align the marks on the timing sprocket and the oil pump drive sprocket with each of the marks on the chain.
  6.  
  7. Install the chain and sprocket assembly over the keyways, while retaining alignment of the chain/sprocket timing marks.
  8.  


CAUTION
Use care not to disengage the welch plug at the rear of the oil pump driveshaft by forcing the sprocket over its keyway.

  1. Install the oil pump drive chain vibration damper.
  2.  
  3. Install the gasket for the timing chain cover.
  4.  

Use liquid sealer on the gasket before installation.

  1. Install both of the chain tensioners in their respective places, being careful not to mix them up. Tighten their securing bolts to 12-17 ft. lbs.
  2.  


CAUTION
Use care when installing the chain tensioner bolts; they have oil holes tapped in them.

  1. Fit the camshaft drive sprocket over the keyway on the oil pump driveshaft. Tighten its securing nut to 58-72 ft. lbs.
  2.  
  3. Install the camshaft drive chain over the camshaft drive sprocket. Align the mating marks on the chain and sprocket.
  4.  
  5. Apply tension to the chain by tying it to the chain tensioner. This will prevent it from falling back into the timing chain cover once it is installed.
  6.  
  7. Install the timing chain cover and cylinder head as previously outlined.
  8.  



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Fig. Fig. 1: Timing chain and gear-8R-C and 18R-C engines



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Fig. Fig. 2: Timing chain stretch measurement-8R-C and 18R-C engines

20R, 22R, 22R-E and 22R-TE Engines

See Figures 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18

  1. Remove the cylinder head and timing chain cover as previously outlined.
  2.  
  3. Separate the chain from the damper, and remove the chain, complete with the camshaft sprocket.
  4.  
  5. Remove the crankshaft sprocket and the oil pump drive with a puller.
  6.  
  7. Inspect the chain for wear or damage. Replace it if necessary.
  8.  
  9. Inspect the chain tensioner for wear. If it measures less than 11mm, replace it.
  10.  
  11. Check the dampers for wear. If their measurements are below the following specifications, replace them:

    Upper damper: 5.0mm
     
    Lower damper: 4.5mm
     

  12.  

To install:
  1. Rotate the crankshaft until its key is at TDC. Slide the sprocket in place over the key.
  2.  
  3. Place the chain over the sprocket so that its single bright link aligns with the mark on the camshaft sprocket.
  4.  
  5. Install the cam sprocket so that the timing mark falls between the two bright links on the chain.
  6.  
  7. Fit the oil pump drive spline over the crankshaft key.
  8.  
  9. Install the timing cover gasket on the front of the block.
  10.  
  11. Rotate the camshaft sprocket counterclockwise to remove the slack from the chain.
  12.  
  13. Install the timing chain cover and cylinder head as previously outlined.
  14.  



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Fig. Fig. 3: Timing chain-to-crankshaft alignment-20R, 22R, 22R-E and 22R-TE engines



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Fig. Fig. 4: Timing chain-to-camshaft alignment-20R, 22R, 22R-E and 22R-TE engines



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Fig. Fig. 5: Timing mark locations-22R engine



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Fig. Fig. 6: Removing the distributor and fuel pump drive gear assembly retaining bolt



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Fig. Fig. 7: Removing the distributor and fuel pump drive gear assembly



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Fig. Fig. 8: Removing the timing cover front bolt



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Fig. Fig. 9: Timing cover front bolt



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Fig. Fig. 10: Removing the drive spline



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Fig. Fig. 11: Removing the timing cover



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Fig. Fig. 12: Timing chain tied-to-sprocket



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Fig. Fig. 13: Removing the timing chain tensioner mounting bolts



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Fig. Fig. 14: Removing the timing chain tensioner assembly



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Fig. Fig. 15: Removing the timing chain damper



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Fig. Fig. 16: Inspecting the timing chain tensioner assembly for wear



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Fig. Fig. 17: View of the timing chain and related parts



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Fig. Fig. 18: Cleaning the timing chain cover

 
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