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Timing Chain: Removal & Installation Lexus LX J80

Mechanical 8 illustrations ~1544 words

Removal

  1. Drain cooling system and engine oil. Remove lower engine cover. Remove accessory drive belts. Remove cooling fan, water pump pulley, shroud and radiator.
  2. Remove A/C compressor with hoses attached and secure aside. Remove A/C compressor bracket from cylinder block. Remove radiator coolant pipe and hose from cylinder block. (Scheme 19) Remove bolts/nuts, water pump and gasket. Remove cylinder head. See «CYLINDER HEAD»(ref-49416-S20264278112001011500000). Remove No. 1 and 2 oil pans. See OIL PAN.
  3. Using Pulley Holder (SST 09213-58012) and Handle (SST 09330-00021), hold crankshaft pulley. Remove crankshaft pulley bolt. Using puller, remove crankshaft pulley. NOTE: Oil pump drive shaft gear thrust clearance must be checked before removing timing chain cover.
  4. Using dial indicator, check oil pump drive shaft gear thrust clearance when moving gear back and forth. (Scheme 20) Standard oil pump drive shaft gear thrust clearance is.0016-.0063" (.040-.160 mm) with maximum thrust clearance of.0118" (.300 mm). Replace oil pump drive shaft gear and or/timing chain cover if thrust clearance exceeds maximum specification.
  5. Remove drive belt idler pulley and drive belt adjusting bar. (Scheme 19) Remove bolts from timing chain cover. Note bolt length and location for reassembly reference. Remove timing chain cover by gently prying between cylinder block and timing chain cover.
  6. Remove "O" rings from rear of timing chain cover. Remove timing chain and camshaft sprocket. Remove crankshaft sprocket, damper and slipper. (Scheme 19)
  7. Remove bolt and oil jet from front of cylinder block. Remove crankshaft rotor and oil pump drive shaft gear. (Scheme 19) If removing pump drive shaft gear, place shop towels against block. Using 2 screwdrivers, pry pump drive shaft gear from crankshaft.

Scheme 19

Scheme 19
Scheme 19

Scheme 20

Scheme 20
Scheme 20

Installation

  1. If installing crankshaft front seal in timing chain cover, use hammer, Handle (SST 09316-00011) and Seal Installer (SST 09316-00051). Install seal until seal surface is even with timing chain cover. Apply grease to seal lip of seal.
  2. If installing pump drive shaft gear on crankshaft, rotate crankshaft until key in crankshaft is facing downward. Install pump drive shaft gear on crankshaft. If installing oil pump drive shaft gear, apply engine oil to splines at center of gear where shaft of oil pump drive rotor engages. Install oil pump drive shaft gear. CAUTION: Ensure crankshaft rotor is installed with flat side toward cylinder block. (Scheme 19)
  3. Install crankshaft rotor with flat side of crankshaft rotor toward cylinder block. (Scheme 19) Install oil jet on cylinder block. Install and tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-49416-S15026808592001011500000). Install damper and slipper. Install and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49416-S15026808592001011500000). Ensure slipper moves smoothly. CAUTION: Ensure crankshaft sprocket is installed with flat side toward cylinder block. (Scheme 19)
  4. Install crankshaft sprocket with flat side toward cylinder block and crankshaft rotor. (Scheme 19) If necessary, use hammer and Sprocket Installer (SST 09636-20010) to install crankshaft sprocket.
  5. Install timing chain. Align bright links on timing chain with timing mark on camshaft sprocket (STEP 1), and on crankshaft sprocket (STEP 2). (Scheme 21)
  6. Place tie around timing chain to ensure timing chain does not come loose (STEP 3). (Scheme 21) Ensure sealing surfaces on front of cylinder block and rear of timing chain cover are clean. Apply sealant to rear of timing chain cover. Ensure sealant does not enter "O" ring areas on timing chain cover. (Scheme 22) CAUTION: When installing timing chain cover, ensure splines on drive rotor of oil pump in timing chain cover fully engage with oil pump drive shaft gear, or components may be damaged.
  7. Install NEW "O" rings on rear of timing chain cover. Install timing chain cover on cylinder block. Engage gears of oil pump drive rotor and drive gear, and install oil pump. Install drive belt adjusting bar and bolts/nuts of timing chain cover. Ensure proper length bolt is installed in designated area. (Scheme 23) Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49416-S15026808592001011500000). Remove tie from timing chain.
  8. Install drive belt idler pulley and crankshaft pulley. Install and tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-49416-S15026808592001011500000). Install No. 1 and 2 oil pans. See «OIL PAN»(ref-49416-S40138827002001011500000).
  9. Install cylinder head using proper procedure. See «CYLINDER HEAD»(ref-49416-S20264278112001011500000). To install remaining components, reverse removal procedure. Tighten bolts/nuts to specification. See «TORQUE SPECIFICATIONS»(ref-49416-S15026808592001011500000). Fill crankcase and cooling system.

Scheme 21

Scheme 21
Scheme 21

Scheme 22

Scheme 22
Scheme 22

Scheme 23

Scheme 23
Scheme 23

Camshaft must be removed for valve lifter removal. See CAMSHAFT . Note location of adjusting shims and valve lifters for reassembly reference. Remove valve lifters and adjusting shims from cylinder head.

To install, reverse removal procedure. Coat components with engine oil before installing. Ensure components are installed in original location and valve lifter rotates smoothly in cylinder head. If camshaft, adjusting shims or valve lifters are replaced, check valve clearance. See VALVE CLEARANCE ADJUSTMENT under ADJUSTMENTS.

Scheme 24

Scheme 24: Removal
Scheme 24: Removal
  1. Drain cooling system. Disconnect PCV hoses. Remove air intake hose located between throttle body and airflow meter. Disconnect control cables, coolant hoses, electrical connectors and vacuum hoses at throttle body. Remove throttle body and gasket.
  2. Remove heater coolant valve and engine wiring from firewall for access to valve cover. Remove spark plug wire covers from valve cover. Disconnect plug wires from spark plugs. Remove bolts, valve cover and gasket. Rotate crankshaft clockwise so cylinder No. 1 is at TDC on compression stroke. Ensure timing mark on crankshaft pulley aligns with "0" mark on timing chain cover.
  3. Ensure one-dot timing marks on camshaft sprockets are aligned. see scheme 2 Ensure 2-dot timing marks are even with cylinder head surface. If one-dot timing marks are not aligned, rotate crankshaft clockwise one full revolution (360 degrees).
  4. Remove nuts, timing chain tensioner and gasket from cylinder head. see scheme 10 Remove half-circular plug from front of cylinder head. Place reference mark on timing chain and camshaft sprocket for reassembly reference.
  5. Hold intake camshaft by placing wrench on hexagonal portion of camshaft. Remove camshaft sprocket bolt and distributor gear. see scheme 10 Remove camshaft sprocket with timing chain, allowing camshaft sprocket and timing chain to rest on slipper and damper. (Scheme 19) CAUTION: DO NOT allow timing chain to disengage from crankshaft sprocket. NOTE: Camshaft bearing caps are numbered for location. No. 1 bearing cap is forward, near timing chain; No. 7 is at rear. Camshaft bearing caps are stamped with an "I" for intake camshaft, and "E" for exhaust camshaft. Install bearing caps with arrow pointing forward. CAUTION: Camshafts must be properly positioned to lift camshaft straight from cylinder head to prevent damage to cylinder head and camshaft. DO NOT pry or force camshafts from cylinder head as component damage may result.
  6. For exhaust camshaft removal, use wrench on hexagonal portion of camshaft to rotate exhaust camshaft for access to service bolt hole on sub-gear. Secure sub-gear on exhaust camshaft to main gear using a 6 x 1 x 18-mm service bolt "B". (Scheme 24) Before removing camshaft bearing cap bolts, ensure torsional spring force of sub-gear is held by service bolt "B".
  7. Rotate intake camshaft to position 2-dot timing mark at a 35-degree angle (STEP 1). (Scheme 25) Lightly push exhaust camshaft toward rear of cylinderhead.
  8. Alternately loosen bolts on No. 1 exhaust camshaft bearing cap. Remove No. 1 exhaust camshaft bearing cap. Alternately loosen and remove No. 2, 3, 5 and 7 exhaust camshaft bearing cap bolts. DO NOT loosen No. 4 and 6 exhaust camshaft bearing cap bolts. Remove No. 2, 3, 5 and 7 exhaust camshaft bearing caps.
  9. Alternately loosen No. 4 and 6 exhaust camshaft bearing cap bolts. Ensure camshaft is lifted upward evenly as No. 4 and 6 exhaust camshaft bearing cap bolts are removed. Remove No. 4 and 6 exhaust camshaft bearing caps and exhaust camshaft. NOTE: If exhaust camshaft is not lifted upward evenly, retighten No. 4 and 6 exhaust camshaft bearing cap bolts. Reinstall all exhaust camshaft bearing caps and reposition timing mark. Repeat procedure and remove exhaust camshaft.
  10. For intake camshaft removal, rotate intake camshaft so 2-dot timing mark is at 25-degree angle (STEP 2). (Scheme 25) This aids in camshaft removal by using lobes on cylinder No. 1 and 4 to push on valve lifters.
  11. Lightly push intake camshaft toward front of cylinder head. Alternately loosen bolts on No. 1 intake camshaft bearing cap. Remove No. 1 intake camshaft bearing cap.
  12. Alternately loosen and remove No. 3, 4, 6 and 7 intake camshaft bearing cap bolts. DO NOT loosen No. 2 and 5 intake camshaft bearing cap bolts. Remove No. 3, 4, 6 and 7 intake camshaft bearing caps.
  13. Alternately loosen No. 2 and 5 intake camshaft bearing cap bolts. Ensure intake camshaft is lifted upward evenly as No. 2 and 5 camshaft bearing caps bolts are removed. Remove No. 2 and 5 intake camshaft bearing caps and intake camshaft. NOTE: If intake camshaft is not lifted upward evenly, retighten No. 2 and 5 intake camshaft bearing cap bolts. Reinstall all intake camshaft bearing caps and reposition timing mark. Repeat procedure and remove intake camshaft.
  14. If removing sub-gear from exhaust camshaft, install service bolt "A" in camshaft. (Scheme 26) Using screwdriver, rotate sub-gear clockwise and remove service bolt "B". Remove snap ring, wave washer, sub-gear and gear spring from exhaust camshaft. see scheme 10
  15. Remove valve lifters and adjusting shims from cylinder head (if necessary). Mark component location for reassembly reference. Components must be installed in original location.

Scheme 25

Scheme 25
Scheme 25

Scheme 26

Scheme 26
Scheme 26

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