Camshaft Gear/Sprocket: Service and Repair
Removing and installing camshaft timing gearTools
Preliminary work
1. Remove camshaft housing cover.
Tools and materials
Special tools
Tools:
Removing camshaft timing gear
ATTENTION: Engine damage due to turning the crankshaft against the running direction (engine assembled)!
--> Never turn the engine against the running direction when the timing drive mechanism is fitted (timing chain may jump over).
--> Proceed carefully while working as otherwise engine damage may occur.
--> Only turn the engine on the crankshaft and never on the camshaft as the timing chain can jump over.
--> After working on the camshaft timing gears, the timing must be adjusted.
--> Please observe the general warning notes and working regulations --> '10 The most important working regulations and warning notes'
ATTENTION: Engine damage due to turning the crankshaft against the running direction (engine assembled)!
--> Never turn the engine against the running direction when the timing drive mechanism is fitted (timing chain may jump over).
--> Proceed carefully while working as otherwise engine damage may occur.
--> Only turn the engine on the crankshaft and never on the camshaft as the timing chain can jump over.
--> After working on the camshaft timing gears, the timing must be adjusted.
--> Please observe the general warning notes and working regulations --> '10 The most important working regulations and warning notes'
ATTENTION: Engine damage due to turning the crankshaft against the running direction (engine assembled)!
--> Never turn the engine against the running direction when the timing drive mechanism is fitted (timing chain may jump over).
--> Proceed carefully while working as otherwise engine damage may occur.
--> Only turn the engine on the crankshaft and never on the camshaft as the timing chain can jump over.
--> After working on the camshaft timing gears, the timing must be adjusted.
--> Please observe the general warning notes and working regulations --> '10 The most important working regulations and warning notes'
1. Using socket 9714, turn the crankshaft until cylinder 1 is located at ignition TDC.
View Shows Position Of Cams On Cylinder 1:
View Shows Position Of Cams On Cylinder 5:
Note: If the cams on cylinder 1 are not positioned as shown, check whether the crankshaft still needs to be turned through another turn (360°)!
2. Ensure the cams of cylinders 1 and 5 are in the position shown (ignition TDC) -see figure- and --> View shows position of cams on cylinder 5.
View Shows TDC Position Of Crankshaft:
3. Insert locating pin 9595/1 through the bore provided in the crankshaft gearwheel and into the relevant groove in the timing chain housing cover -see figure-.
Installation Location Of Chain Tensioner:
4. Remove chain tensioner -arrow-.
Upper Plastic Guide For Timing Chain:
5. Loosen timing chain and pull upper plastic guide away from both pins. If necessary, turn camshaft timing gear back and forth a little with the ring wrench so that the timing chain has more play between the wheels --> Upper plastic guide for timing chain.
Loosening Camshaft Timing Gear:
Note:
^ The fastening screws of the sprockets must be replaced after removal.
^ The diamond washers of the chain sprockets must be replaced after removal.
^ The screws of the sprocket wheels are tightened by hand during assembly and are then loosened by one or two turns. This play is necessary so that the camshafts can still be turned.
6. Just loosen the fastening screw of the camshaft adjuster (1 or 2 turns). To do this, counter the a/f 32 hexagon of the camshaft adjuster and camshaft timing gear with a ring wrench. Only remove the cheese head bolt of the camshaft timing gear -to illustrate the operation more clearly, the figure does not include the timing case cover- -.
7. If necessary, use a rubber hammer to carefully loosen the camshaft timing gear from the back.
ATTENTION: Engine damage due to small parts falling into the timing case (e.g. diamond washer)!
--> Do not let the diamond washer under the camshaft timing gear and camshaft adjuster fall into the timing case.
Note: There is a diamond washer between the camshaft and camshaft timing gear and between the camshaft and camshaft adjuster. This is to be replaced after the corresponding wheel has been removed. If the fastening screw of the wheel is only loosened to adjust the timing (1 or 2 revolutions), the diamond washer does not need to be replaced.
8. Use both hands, to carefully remove the camshaft timing gear from the chain.
Removing Diamond Washer:
ATTENTION: Engine damage due to small parts falling into the timing case (e.g. diamond washer)!
--> Do not let the diamond washer under the camshaft timing gear and camshaft adjuster fall into the timing case.
9. Remove the diamond washer located under the camshaft adjuster. In this case (removal of camshaft timing gear) replace the diamond washer.
Installing camshaft timing gear
Note: If they have been removed, replace the diamond washer and M12 cheese head screw of the camshaft.
Replacing The Diamond Washer:
1. Replace the diamond washer and M12 cheese head screw located under the camshaft timing gear.
2. Lift the timing chain and carefully place the camshaft timing gear on the camshaft. To get sufficient play in the timing chain, it may be necessary to turn the loosened camshaft adjuster back and forth. Place timing chain on camshaft timing gear.
3. Position new M12 fastening screw on camshaft timing gear and screw in loosely (it must still be possible to turn the camshaft timing gear).
4. Fit plastic guide for the timing chain.
Installation Location Of Chain Tensioner:
5. Install chain tensioner -arrow-.
Subsequent work
1. Adjust timing for the camshafts'. After adjusting the timing, tighten the camshaft timing gears and camshaft adjusters Initial tightening 7.5 ft. lbs.. Initial tightening 37 ft. lbs. Final tightening 135° Initial tightening 7.5 ft. lbs.. Initial tightening 37 ft. lbs.. Final tightening 90°.
2. Install camshaft housing cover.