Removing and Installing Tensioning Rail

Removal
1 Remove radiator and fan.






2 Remove cylinder head cover.

On engines with automatic transmissions and vacuum-controlled modulating pressure, additionally detach vacuum lines at switchover 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 design (A, figure, step 8). Remove chain tensioner. Removing and Installing Chain Tensioner

On vehicles with air-conditioners, detach York A/C compressor together with connected lines, depositing on one side. However, first remove water pump pulley, additionally removing air cleaner cover on engines with oil bath air cleaners. Drain coolant and detach thermostat body.

On engine 617.912, remove adapter at air cleaner.

4 On engine 617 remove pulley and vibration damper,and on engine 616 take out pulley. On engine 615.940 with 12.5 mm alternator V-belt, also remove pulley.






5 Using tool combination, turn crankshaft until recess in balance plate appears at tension rail bearing pin (image, step No. 10).






6 Mark positions of camshaft sprocket and timing chain to show how they fit together.










7 Remove slide rail or rails from cylinder head. Withdraw hearing pin using impact extractor.

On vehicles with level control, detach delivery oil pump together with connected lines, depositing on one side.






8 On engines with light metal tension rail version (B) force back thrust pin of chain tensioner.






9 Remove camshaft sprocket. To release waisted bolt secure camshaft sprocket with screwdriver or steel pin.






10 Withdraw bearing pin using impact extractor.






CAUTION: If bearing pin is so tight that it resists removal with impact extractor it will then have to be removed using remover as per part No.115 589 20 33 00.

11 Take tension rail out in upward direction.


Installation





12 Coat bearing pin collar with sealant.
13 Position tension rail and drive bearing pin home, using impact extractor.
14 Place camshaft sprocket and timing chain on cam-shaft with reference to markings.
15 Apply waisted bolts for camshaft sprocket and torque to 80 Nm (8 kpm). For this purpose secure camshaft sprocket with screwdriver or steel pin.
16 Fit chain tensioner.
17 Fit slide rail.
18 Now proceed in reverse order of removal.
19 Fill cooling system with coolant and then pressure-test.