Inspection and Replacement of Camshaft Bearing

08028-0D/H5250/94.08.12

Safety precautions:

Stopped engine

Shut-off starting air

Shut-off cooling water

Shut-off fuel oil

Shut-off cooling oil

Stopped lub. oil circul.

Description:

Check of roller path of cams and check of camshaft bearing.

Replacement of camshaft bearing.

Starting position:

Cover for camshaft and gear wheel has been removed.

Related procedure:

Hand tools:

Ring and open end spanner, 19 mm. Socket spanner, 19 mm.

Feeler gauge. Big screw driver.

Replacement and wearing parts:

L23/30H

To Check Roller Path of Cams.

1) While turning the engine, examine the cam discs and in particular, check the roller path of all cams for cracks, crackles and ruffle. Also examine the rollers of the roller guides.

Note: if there are flat spots on the roller and if some of the rollers may be blocked, the roller must be replaced by a new one, see working card 508-01.00.

To Check Camshaft Bearings.

2) The wearing surface of the camshaft bearings cannot be checked without dismounting the camshaft. However, ab-normal wear of one or more bearings will become apparent in the form of burrs of white metal at the circumference of the camshaft journal, and in that case the bearing will in no doubt be discoloured, as well.

The bearing clearance is measured with a feeler gauge, see data sheet 500.35.

To Replace Camshaft Bearing.

3) If one or several of the camshaft bearings should be replaced, the camshaft must be wholly or partly dismantled.

Dismount the fuel oil feed pump, if mounted, and check that the camshaft sections are marked in relation to each other. Disassemble the camshaft aft (toward flywheel) of the bearing that is to be replaced. Dismount all roller guides that are located forward of the disassembling position, see working card 508-01.00 and 508-01.05.

Pull the disconnected sections of the camshaft so far a head that the bearing which is to be replaced is free.

Take out the locating screw of the camshaft bearing concerned and push the bearing out of the bore in the engine frame, see fig 1.

Check the lubricating oil ducts to the bearing for free flow.

Camshaft bearing

Hole for lubricating oil

Locating screw

Frame

Fig 1.

Mount a new camshaft bearing in the bore and make sure that the hole for insertion of the locating screw in the bearing is in a correct position. Lock the bearing by means of the locating screw, which is to be provided with a new gasket. To facilitate the fitting of the bearing it can be cooled down with Co2.

Inspect the camshaft journal for seizures.

If necessary, the camshaft section must be entirely removed from the engine, and the journal concerned must be polished.

Coat all the journals of the camshaft section with clean lubricating oil and push the camshaft into position, making sure that the marks on the flanges coincide.

Assemble the sections and fit the bolts (coated with copaslip or similar).

Tighten the nuts with a torque spanner, see data sheet 500.40.

Mount all roller guides as well as the fuel oil feed pump.

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

L23/30H

If the intermediate wheel has been dismantled a nominal adjustment of the camshaft compared to the crankshaft (timing) must be made as follows:

1) The crankshaft is turned to TDC (top dead centre) for cylinder no 1.

Cylinder numbering, see page 500.11.

2) Roller guide for fuel oil pump cylinder no. 1 is mounted and the camshaft is turned in a position where the roller guide rests on the cicular part af the cam, see fig 1.

Roller guide

Cam for

exhaust valve

Cam for fuel oil pump

Seen from front edge

Fig 1.

3) The "nominal size" is measured with a depth gauge, i.e. the distance from the upper edge of the roller guide house to the thrust gauge pressed into the roller guide, see fig 2.

"Nominal size"

Fig 2.

4) The camshaft is turned - in the engines direction of rotation (see page 500.12) - until the "nominal size" (as described in item 3) is reduced with the lead, mentioned in "Lead of Fuel Pump".

Note: "Lead of fuel pump" is shown in the table "Adjusment after the trail" in the Shop Test Protocol.

5) When items 1 - 4 are completed and correct the intermediate wheel can be mounted and tightened up again (torque moment, see page 500.40).

For adjustment of the single fuel oil pumps (separately and assembled), see working card 514-05.01.

08028-0D/H5250/94.08.12