Timing Chain: Service and Repair
Timing gear chains, replacementSpecial tools: 5103, 5112, 5329 (drift)
When the chains are replaced, the pulleys and strainers behind the chain tensioners should also be replaced. All other parts should be replaced as needed.
Draining coolant
Remove:
- negative battery cable.
- cap on expansion tank (2)
- vacuum hose from heating system water valve (8)
- engine splashguard
- place a drip pan under engine. Disconnect lower coolant hose (l)from radiator.
Remove:
- oil pipes (la and lb) from radiator. Hold the nipples on radiator with wrench to prevent their coming loose.
- cables to thermoswitch (2) in radiator (cars with electric cooling fan).
- hoses (3a and 3b) from radiator to expansion tank.
- upper hose (4) from coolant pump.
- lower hose from coolant pump (not seen in picture but directly under upper one).
- two bolts (5a) fastening the fan cover to radiator. radiator (6).
- fan housing (5b).
^ Remove cooling fan.
^ Remove clamp (at arrow) holding cable harness to timing gear cover.
Loosen alternator drive belts
Loosen nut and bolt (2) holding alternator to tensioner bracket (1) and lower bolt (3). Using the adjustment bolt as handle (4) push alternator towards engine until the drive belts are loose.
Remove coolant pump pulley (5).
Remove:
^ protective cover (1a)
^ distributor cap (1b)
^ rotor (2)
^ camshaft centre bolt (3)
^ rotor holder (4)
^ dust cover (5a)
^ O-ring (5b)
^ distributor housing (6)
Remove left valve cover
Remove:
^ Air intake hose (9)
^ Main cable harness clamp (10) from valve cover
^ Ignition cables and fuel pipes from bracket (11) on valve cover
Expose and remove right valve cover
Remove
^ Oil tiller cap with hoses (2)
^ EGR valve with pipes (9a and 9b) and vacuum hose (10)
^ Separate connector (3) on cable to compressor (4a)
Release, move aside and fasten compressor (4a), compressor bracket (4b) and belt tensioner.
Note! Belt tensioner pulley must not touch battery negative pole.
^ Pulley for A/C belt (5)
^ Dipstick on valve cover (6)
^ Clamp (7) around cable harness valve cover (8)
Loosen drive belt for servo pump.
Remove servo pump and bracket from engine
First remove pump. Hang it by a wire or something similar. Then remove bracket.
Turn crankshaft to TDC on exhaust/intake stroke for cylinder 1.
Marking 1 on belt pulley should be opposite 0 mark on ignition setting plate. Both cylinder 1 rockers should make contact.
Lock flywheel in place
Remove cover plate on left side of flywheel (Right hand drive = right side).
Insert locking gear segment 5112 at the upper bolt to hold flywheel in place (Right hand drive = lower bolt).
Remove crankshaft pulley 36 mm socket.
Take care that crankshaft key does not fall. Remove locking gear segment 5112.
Remove timing gear cover
Put the distributor shaft extension (1) in a safe place.
^ Cover hole to oil sump with paper (arrow in picture).
Loosen right camshaft centre bolt
^ 10 mm socket screw.
If necessary, use a screwdriver to lock camshaft in place.
^ (Use a screwdriver with a round shaft to prevent damage to valve cover gasket surfaces).
Loosen timing gear chains
Turn each chain tensioner 1/4 turn counter-clockwise and press in piston.
Remove:
^ oil pump chain and sprocket
^ chain tensioners and oil strainers
^ curved and straight vibration dampers
^ camshaft sprockets and chains
Remove from crankshaft:
^ outer sprocket
^ spacer and key
^ inner sprocket and key
If necessary, use a puller for sprockets.
Clean and check vibration dampers and tensioners
Note! Do not disassemble tensioners. If the locking pawl falls out, the tensioners must be replaced.
- Check that oil paths in tensioners are clear.
- Check dampers for damage and wear.
- Replace parts as necessary.
Remove front crankshaft seal (1) and distributor shaft extension seal (2)
Remove all remaining gasket pieces (use wooden scraper) from:
- cylinder block
- timing gear cover
- valve covers
Install crankshaft pulley and keys
- Fill holes in crankcase to prevent keys from falling into the crankcase.
- Oil all parts.
- The marking (a line) on the inner sprocket should be aligned outwards.
Note! Do not interchange left and right camshaft sprockets on B280.
The left (A) and right (B) sprockets can be identified since the small holes have different shapes. (see picture)
(NOTE! Engine in picture is viewed from front.)
Install left camshaft chain and sprocket
- Place chain on sprocket with line on sprocket between the two lines on the chain.
Place chain over inner crankshaft sprocket so line on chain corresponds to line on sprocket.
- Tighten chain on pulling side (the side which is next to the straight vibration damper).
Install camshaft sprocket so that pin on sprocket fits into groove on camshaft.
- Install centre bolt and distributor shaft extension. Hand tighten.
Install (left side):
- Curved vibration damper (A). Use thread locking compound 161 053-2 on bolts.
- New strainer in cylinder block.
- Chain tensioner (B).
- Straight vibration damper (C)
Set crankshaft and right camshaft
- Install crankshaft nut. Turn crankshaft clockwise until crankshaft key points directly down.
- Groove in camshaft should point out (see picture).
Note! Centre line (B) should be parallel to line (A) along gasket surface of valve cover.
Install right camshaft chain and sprocket
- Place chain on camshaft sprocket with line on sprocket between the two lines on chain.
- Place chain on crankshaft sprocket so that line on chain corresponds with line on sprocket.
- Tighten chain on pulling side (the side which is next to the straight vibration damper).
- Install camshaft sprocket so that pin on sprocket fits into groove on camshaft. If necessary, turn crankshaft somewhat.
- Install centre bolt.
Install on right side:
- curved vibration damper. Use locking compound (PIN 1161 053-2) on bolts.
- New strainer in cylinder block.
- Chain tensioner.
- Straight vibration damper
Tighten right camshaft centre bolt
- Torque to 70-90 Nm (51-66 ft lb). Brace with screwdriver.
- Left camshaft bolt is tightened later.
Turn locking pawls in chain tensioners 1/4 turn clockwise
Tighten chains
- Turn crankshaft approximately 2 turns.
- Remove crankshaft nut.
Note! Make sure crankshaft key points up to keep it from falling out.
When the crankshaft has been turned the marks on the chain and sprockets will no longer correspond. It will be necessary to turn the crankshaft many times before the marks line up again.
Install:
- chain and sprocket. Use locking compound (P/N 1161 053-2) on sprocket bolts.
Install timing gear cover with gaskets
- Remember to remove protective paper from holes to lower crankcase.
- Use sealing compound (P/N 1161 056-5) on four lower cover bolts.
- Trim gaskets flush against top of cylinder heads.
Front crankshaft seal, pulley
- Grease the seal.
- Install seal in timing gear cover.
- Use mandrel 5103.
- Grease distributor shaft seal.
- Remove left camshaft centre bolt.
- Install distributor shaft seal in timing gear cover.
Use mandrel 5329.
Install:
- distributor housing (6)
- rotor holder (4) (Torque to 70-90 Nm (51-66 ft lb))
- O-ring (5b) and dust cover (5a)
- camshaft centre bolt (3)
- rotor (2)
- distributor cap (lb)
- protective cover (1 a)
Install:
- Lower coolant hose to coolant pump (1).
- Pulley (2).
- Cooling fan (3), hand tighten.
Install crankshaft belt pulley
- Place locking gear segment 5112 at the lower flywheel cover bolt (Right hand drive = upper bolt).
- Be careful so the key doesn't fall out.
- 36 mm socket.
- Torque to 240-280 Nm (177-207 ft lb).
Install cover plate on flywheel cover
- Remove locking gear segment 5112.
Install:
- alternator drive belts (tighten)
- servo pump bracket
- servo pump
- servo pump drive belt (tighten)
If necessary, adjust valve clearances.
Install gaskets and valve covers
Use sealing compound (P/N 1161 026-8) in several places to fasten gaskets.
Install valve covers.
Torque to 10-15 Nm (7-11 ft lb).
In order to make certain that the T shaped joints between cylinder block, valve covers and timing gear cover are completely sealed, a piece of silicone sealant (P/N 1 161 048-2) can be placed in them.
Note! Do not use too much silicone sealant. There is a risk that sealant can enter the lubrication system and plug the oilways.
Tighten the cooling fan bolts.
Install fan shroud and radiator
- fit fan shroud (5b) over fan.
- install radiator (6) and two bolts (5a) fastening the fan shroud to radiator.
- upper radiator hose (4) to coolant pump.
- lower radiator hose to coolant pump. Install shield panel under engine.
- hoses from expansion tank (3a and 3b) to radiator.
- oil pipes (1a and 1b) to radiator. Hold the nipples on radiator with wrench to prevent their coming loose.
- cables to thermo switch (2) in radiator (cars with electric cooling fan).
Install on right side:
- clamp around cable harness (7).
- oil dipstick (6).
- A/C compressor (4a), compressor mount (4b) and the belt tightener (4c).
- compressor belt jockey pulley (5).
- install A/C compressor drive belt and tighten.
- connector (3).
- EGR valve with pipes (9a and 9b) and vacuum hose (10).
- oil filling cap with hoses (2).
- negative battery cable.
Order for installing drive belts:
A. Crankshaft pulley
B. Compressor pulley
C. Tensioner pulley
D. Pulley
Install on left side:
- ignition leads and fuel hoses to bracket (11) on valve cover. Use new tie band (P/N 949 211-8) around fuel lines.
- Clamp main cable harness (10) to valve cover using lie band P/N 949 211-8.
- Air inlet hose (9).
Connect battery negative cable
Install vacuum hose to heating system hot water valve
Fill with coolant. Start engine and let it warm up. Check operation.
Top up with coolant if necessary.
Check and adjust:
- idle speed and CO content.