Main Repair Instructions Disassembly

Remove both cylinder head covers by removing round rubber mounts 1, then remaining bolts (arrows).



Remove thermostat housing cover and thermostat. Unscrew the (20) 6 mm bolts and remove timing case cover.



CAUTION Do not allow the steel dowels (arrows) to fall into the lower timing case.



The right bank (cyl. 1-6) camshaft must be removed to facilitate the upper timing case removal.


Depress each valve assembly with tool 11 3 180 and remove the drag arms and thrust pads.


NOTE

1.) When depressing valve spring assembly, the pertinent piston must never be at top dead center.

2.) Rotate the engine until each cam lobe points straight away from the cylinder head.

3.) The depressing tool must not bear against the cam lobe surface.

4.) Store the drag arms and thrust pads in the order removed and reinstall in the same operating position.

5.) Use "caution" when removing the thrust pads. Cover oil drain holes to prevent accidental entry during removal and installation.



Rotate engine to No. 1 cyl. top dead center (OT = TDC).



Lock engine with tool 11 2 300.


CAUTION Never remove the locatlng pin before the camshaft drive is fully reassembled.

After the engine repair is completed, the locating pin must be removed prior to engine start up.



Valves of cylinders No. 1 and 7 are closed when dowel pins (or dowel pin drillings) face toward inside (arrows).



Remove chain guide rail and retaining clips (arrows). These retaining clips may not be installed in all engines.

CAUTION Cover chain port openings to prevent clips from falling into engine.



Press off anti-tamper cap from chain tensioner.

NOTE The cap will be deformed during removal and must be renewed during final assembly.



Release timing chain tension.

^ Loosen locknut 2.
^ Loosen adjusting screw 1 by several turns.
^ Unscrew tension plug 3.
^ Remove tension spring and piston.

CAUTION Assembly under spring pressure.



Loosen and remove bolts (arrows) and sprocket of right bank (cyl. 1-6).



Loosen and remove bolts and sprocket of left bank (cyl. 7-12).



Unscrew retainlng bolt 1 and remove chain guide rail in upward directlon (arrow).



Remove right bank (cyl. 1-6) cam journal bearing caps and remove camshaft.

NOTE The bearing caps are matched and numbered 1 through 7 and must not be mispositioned. The No. 1 bearing cap is on the sprocket end.



Remove rear timing case sectlon by removing (21) 6 mm bolts. Pull timing case forward and clear of dowel pins.

CAUTION Do not allow the steel dowels to fall into the lower timing case.



Swing the timing case up and out (arrow) as shown.

Remove all old gasket material from all sealing surfaces and inspect for imperfections.

CAUTION When cleaning sealing surfaces:
1.) Do not use sharp metal tools as gouging and damage will result. Use only wooden or plastic edge tools.

2.) Clean and Inspect all blind bolt holes with solvent and moderate compressed air.

3.) Do not allow gasket material or cleaning fluids to enter and contaminate the crankcase via the lower timing case openings.