Press a new valve stem seal B (see photo) onto the IQ-204 mandrel, having previously lubricated it with engine oil. Install the plastic protective cap A onto the valve stem. Insert the 10-204 mandrel for pressing on valve stem seals with the seal pre-installed on it onto the valve stem. Press the valve stem seal firmly onto the 10-204 mandrel until it stops. After removing the mandrel, make sure that the valve stem seal is pressed on correctly.
Note: The valve stem seals can be replaced without removing the cylinder heads as follows:
- remove the camshaft and take out the valve lifters;
- remove the spark plug;
- set the piston of the required cylinder to BDC;
- fix the valve in the upper position with a lever through the spark plug hole;
- remove valve springs;
- replace the valve stem seals as described above.
Install the springs and spring retainers. Install the crackers using a valve spring compressor.
Insert the valve tappets into the head holes, having previously lubricated them with engine oil to facilitate installation. Pay special attention to the tappets being returned to their previous position.
Install adjusting washers except for DT, DS and DZ engine models.
Install the camshaft with its outer journals on two prisms placed on the test plate and measure the radial runout of the middle journal with an indicator, which should not exceed 0.04 mm. If the runout is greater, straighten the shaft on a straightening press.
Lubricate the bearing journals and camshaft lobes with engine oil and place it in the cylinder head supports so that the cams of the 1st cylinder are directed upwards.
Install bearing caps No.2 and 4 alternately crosswise, screw the nuts onto the mounting studs, but do not tighten the nuts completely.
Install bearing caps No.5, 1 and 3 and pre-tighten the fastening nuts, taking into account the offset position of the caps of these bearings relative to the axis.
Install the bearing caps finally into the axle housings by lightly tapping the front flange of the camshaft with a mallet.
Finally tighten the bearing cap fastening nuts to a torque of 1.8-2.1 kgf·m, starting with the nuts of bearing cap No.5.
Press in a new camshaft oil seal using mandrel 10 203.
Install the camshaft toothed pulley and tighten its mounting bolt to a torque of 8 kgf·m.
(The original version of the article is posted on the website audimanual.ru)