Removal and installation camshafts (Mercedes-Benz S-Class W140)

Note: See also Section Timing Drive - General Information, Component Maintenance.

The dimensions of the camshafts are given in Specifications.



The camshaft caps are numbered sequentially, starting with the front right exhaust camshaft cap. The numbers are stamped on the cylinder heads. The bearing caps must be installed in the same position.

Removal

1. Set the piston of the first cylinder to the position 45° before TDC.

2. Remove the top front cover.

3. Mark the relative position of the timing chain relative to the camshaft sprockets.



4. Remove the timing chain tensioner.

5. Remove the upper sliding arms.

6. Remove the timing chain from the camshaft sprockets. Turn the camshafts with the key (1) so that the cams do not press on the hydraulic compensators (see accompanying illustration). Turn the right exhaust sprocket and right intake sprocket approximately 6 teeth in the direction of engine rotation. Turn the left intake sprocket approximately 10 teeth in the opposite direction of engine rotation. Turn the left exhaust sprocket approximately 14 teeth in the direction of engine rotation.



7. Loosen the camshaft bearing caps in sequence to prevent any one-sided stress on the camshaft.

8. Remove the bearing caps and camshafts together with the sprockets and adjusters.

Installation

1. Lubricate the hydraulic lifters and camshaft bearing journals.

Information copied from the website: MERCEDESMAN.ru

2. Install the left intake and exhaust camshafts with the timing chain on the sprockets, but without tension.

3. Lubricate the bearing caps with oil, install and tighten their mounting bolts to 10 Nm. 4. Turn the camshaft with the key (3) and check for ease of rotation.



5. Turn the left exhaust camshaft with the key (3) to the check position. Install the timing chain to the previously marked position, having first blocked the camshaft with the rod (1).

6. Turn the left intake camshaft with the key (3) to the check position. Set the timing chain to the previously marked position, having first blocked the camshaft with the rod (1). The camshaft is in the "lag" position.

7. Install the right intake and exhaust camshafts with the timing chain on the sprockets, but without tension.

8. Lubricate the bearing caps with oil, install and tighten their mounting bolts to 12 Nm. 9. Turn the camshafts and check for ease of rotation.



10. Set the right intake camshaft to the reference position. Set the timing chain to the previously marked position, having first blocked the camshaft with the rod (1). The camshaft is in the "lag" position.



11. Set the right exhaust camshaft to the reference position. Set the timing chain to the previously marked position, having first blocked the camshaft with the rod (1).



12. Further installation is carried out in the reverse order of removal.

13. Check the reference position of the camshafts.