Camshaft - Installation and Timing
caution
The camshaft sprockets are attached to the camshafts using slotted bolt holes. This allows for very accurate valve timing and therefore improved performance and fuel economy. Never fit the camshaft sprockets without correctly setting the camshaft timing using the service tools and timing procedure described below. Severe engine damage will result from incorrect valve timing adjustment.
- Check that the dot mark on the primary gear is still aligned with the line on the crankcase and the service tool T3880601 is installed. Ensure the crankshaft cannot rotate.
- Thoroughly clean the camshafts and journals. Inspect the ends of the camshafts for correct fitment of the sealing plugs. Lubricate the camshafts with clean engine oil before fitting to the head.
- If removed, refit the camshaft sprockets noting their orientation, and secure using the original bolts. DO NOT tighten the fixings at this stage; the sprockets must be free to rotate.
- Refit the camshaft drive chain and, if removed, the tensioner blade and rubbing strip (see Camshaft Drive Chain - Installation).
- Refit the exhaust camshaft to the cylinder head, hooking the camshaft drive chain over the sprocket as you do so.
- Ensure there is no slack between the crankshaft and exhaust sprocket when the sprocket fixings are centrally located within the slotted holes. Ensure alignment marks on the end of the camshaft journals are pointing inwards.
- Refit the inlet camshaft to the cylinder head, hooking the chain over the sprocket as you do so.
- Ensure the fixings on the inlet sprocket are also centrally located within the slotted holes when there is no slack between the exhaust and inlet sprockets. Ensure alignment marks on the end of the camshaft journals are pointing inwards.
- Check that the chain is correctly located around the crankshaft, and both camshaft sprockets.
- Rotate the camshafts until the alignment marks on the end of the camshaft journals are pointing inwards.
- Insert the service tool T3880640 into the camshaft slots, ensuring the removal screw is unscrewed fully, as shown below. Ensure that the tool is centrally located between the camshafts.
T3880640 - Camshaft Timing Plate
Camshaft slots
Removal screw
- Assemble the dowels, spark plug tower O-rings, camshaft ladder and top pad in the same location and orientation as prior to removal.
note
Locate each camshaft to the head ensuring the camshafts are correctly identified (inlet and exhaust) and are also correctly located over their respective valve banks.
Camshaft Alignment Marks |
caution
The service tool T3880640 must be located centrally between the camshafts. Incorrect positioning of the tool may prevent the camshaft ladder locating correctly to the cylinder head during fixing tightening, resulting in incorrect valve timing being set. Severe engine damage will result from incorrect valve timing adjustment.
note
The bolts for the camshaft cap ladder are tightened in two stages.
Stage 1
- Fit and evenly tighten the fixings to 5 Nm, in the sequence shown below.
Camshaft Cover Fixings Tightening Sequence |
Stage 2
- In the sequence shown above, tighten the bolts to 10 Nm.
- Fit the service tool T3880607 using the original fixings and tighten to 8 Nm.
T3880607 - Camshaft Timing Tensioner
- Using the service tool T3880609 and a 6 mm Ball Ended Allen Key, tighten the service tool T3880607 to 0.6 Nm preset by the service tool T3880609.
T3880607 - Camshaft Timing Tensioner
T3880609 - Timing Torque Limiter
6 mm Ball Ended Allen Key
- Tighten the two accessible (uppermost) camshaft sprocket fixings to 22 Nm.
Uppermost fixings
- Remove the service tool T3880601 by rotating the removal screw clockwise as shown below.
T3880640 - Camshaft Timing Plate
Removal screw
- Remove the service tool T3880601.
- Rotate the engine until the remaining two sprocket fixings are accessible.
- Tighten the two remaining camshaft sprocket fixings to 22 Nm.
- Place a suitable wedge between the camshaft drive chain tensioner blade and crankcase, to hold the camshaft drive chain taut during removal of the service tool T3880607.
- Release the tension on Camshaft Timing Tensioner T3880607 and remove it.
- Refit the timing chain tensioner, incorporating a new gasket and O-ring (see Camshaft Drive Chain Tensioner - Installation).
- Rotate the crankshaft clockwise 2 complete turns, using the bolt fitted to the end of the crankshaft. Stop rotation when number 1 cylinder is at Top Dead Centre (TDC), that is when the dot mark on the primary gear aligns with the line on the crankcase.
- Insert the service tool T3880601 into the timing holes in the crankcase and crankshaft.
Dot mark
Marker line
T3880601 - Camshaft Timing Pin
Timing hole in crankcase
- Check that the timing marks are still approximately aligned (to check that the camshaft timing has not moved during service tool T3880607 removal).
- Remove the service tool T3880601.
- Check the valve clearances. Adjust as necessary (see Valve Clearance Measurement).
caution
The torque value stated is very important to accurate timing. Always use the correct value of 0.6 Nm, as set using the service tool T3880609. Using an incorrect torque value will result in incorrect valve timing being set, or damage to the tensioner blade or other valve train components. Either condition may result in serious damage to the engine, reduced engine performance, or reduced fuel economy.
caution
Always check that the service tool T3880640 has been removed before rotating the engine. Severe damage will result to the camshafts or service tool T3880640 if engine rotation is attempted with the tool installed.
note
Before inserting the timing pin, ensure the 'dot' on the primary gear is aligned with the line on the crankcase.
Perform the following operations
Perform the following operations: