Removal of axes of yokes in gathering
Before removing the axles complete with the rocker arms, install the clamps to prevent the hydraulic compensators from falling out of the rocker arms of the valves.
Also, when disassembling the rocker shaft, lay them out according to the cylinder number and intake or exhaust valves so as not to mix up the parts during assembly.
Removing the camshaft
Turn away bolts of fastening of covers of bearings of camshafts. Remove bearing caps, camshafts (shaft), pushers and gap compensators.
When removing the camshaft from the cylinder head, be careful and attentive to protect it from accidental damage.
Attention! Turn away bolts of fastening of covers of bearings in several steps in order to avoid deformation of a camshaft.
Checking the axial clearance of the camshaft (shafts)
Install the camshafts or shaft into the block head.
By shifting it in the axial direction, measure the axial clearance with an indicator.
Nominal axial clearance: 0.5–0.08 mm.
Maximum allowable axial clearance: 0.20 mm.
If the axial clearance exceeds the maximum allowable value, replace the cylinder head. If the camshaft bearing journals are damaged, replace the camshaft (shafts). Clean the oil passages in the cylinder head.
Check the diameter of the camshaft bearing journals. If the measured value does not correspond to the standard value, then check the oil clearance between the journal and the camshaft bearing.
Standard value: 45.0 mm.
Measuring the oil clearance of the camshaft journals
Clean the bearing caps and camshaft journals.
Install the camshafts in the cylinder head.
Lay collapsible plastic gauges axially on all camshaft journals.
Install the camshaft bearing caps.
Note. Do not rotate camshafts.
Remove the bearing caps again.
Measure the collapsible plastic gauges at their widest point.
- Nominal oil clearance: 0.05–0.09 mm.
- Maximum allowable oil clearance: 0.12 mm.
Note. After measurement, completely remove the remnants of the crushed plastic gauge.
Note. If the oil clearance exceeds the maximum allowable value, replace the cylinder head or camshaft.
Checking the camshaft cams
Measure the height of the camshaft cams. If the measured value is less than the limit value, replace the camshaft.
Jaw height (mm)
Engine 4G64
Jaw height (mm)
Engine 4G69
Checking the camshaft on the stand
Install the camshaft on the stand and measure the runout of the shaft on the middle neck. If the runout exceeds the limit, replace the camshaft.
- Standard value: less than 0.02 mm.
- Limit value: 0.10 mm.
Checking rocker arms and their axles
Check the surface of the pressure roller of the rocker arm and the rocker arm pusher, if there is wear or damage, replace the rocker arm
Check for smooth rotation of the pressure roller and replace the valve rocker if there is sticking or excessive play.
Measure the inside diameter of the rocker arm bushing (under axle). Replace the rocker arm if there is excessive bushing wear.
Examine the outer surface (around the circumference) rocker arm axle, on which the rocker arm is installed, if uneven or increased wear is noticed on it, replace the rocker arm axle.
Inspect and clean the oil holes in the rocker shaft.
Check the clearance between the bushing and the rocker shaft. If the clearance exceeds the standard value, then replace the rocker arms and rocker shaft.
Standard clearance: 0.02–0.05 mm.
Installing the camshaft oil seal
Apply a thin coat of engine oil to the seal lip around its entire circumference.
Using a special mandrel, press the oil seal onto the shaft.