Timing Chain: Service and Repair

Replacement





1 Screw out glow plug using 20.8 mm box wrench.






2 Remove cylinder head cover.

On vehicles with automatic transmissions and vacuum controlled modulating pressure, additionally detach vacuum lines at switch-over valve.

CAUTION: Be sure not to cross vacuum lines. The pipe unions and vacuum lines are color coded.






On engines with longitudinal control spindles, detach all control rods. Withdraw retainer (arrow) and force longitudinal control spindle in aft direction. Unscrew bracket (1) and unclip idle control cable (2) with plastic sleeve (3)






3 On engines with tension rail version (A) remove chain tensioner. Service and Repair
On vehicles with air-conditioners, detach York A/C compressor together with connected lines, depositing on one side. However, first remove fan and water pump pulley, additionally removing air cleaner cover on engines with oil bath air cleaners. Drain coolant and detach thermostat body.






4 On engine 617.912 remove adapter at air cleaner.
5 Cover chain guard with cloth and grind open both pins of a link in timing chain.
6 Attach new timing chain to old timing chain by means of a plug link






7 Using tool combination, slowly turn crankshaft in normal direction, simultaneously raising old timing chain until split link arrives at top of camshaft sprocket.

CAUTION: Timing chain must continue to mesh with camshaft sprocket and crankshaft sprocket.






8 Detach old timing chain and connect ends of new one with split link.
For this purpose hold chain ends on camshaft sprocket with a piece of wire.
Insert split link into chain from behind (arrow).






9 Insert outer fishplate of split link, enclosed loosely, (with impressed IWIS mark) into installer (arrow). The outer fishplate is held magnetically.






10 Place installer on split link and press-on fishplate to stop, while holding installer at vertical lever.






11 Relocate die (02) of assembly tool in such a manner, that the notch (arrow) is pointing forward.






12 Hold assembly tool on handle and rivet chain bolts individually.
(Tightening torque of spindle approx. 30 - 35 Nm - reference value.)






13 Check chain bolt rivet and rivet again, if required (arrows).






14 Turn crankshaft and check adjusting marks at engine TDC.

NOTE: Should adjusting marks not agree it will be necessary to check camshaft timing, and start of delivery at injection pump.

15 Install chain tensioner.
16 Using 20.8 mm box wrench, insert glow plugs and then connect.
17 Fit cylinder head cover.
18 On vehicles with tension rail version (A in image, step No. 3) fill cooling system with coolant and then pressure-test.