7 семестр (Бормотов А) / 1man_bw_l23_30_chn_23_30_instruktsiya_po_ekspluatatsii_1 / MAN-BW L23-30 H Vol-1 (Instruction)+

08028-0D/H5250/94.08.12

L23/30H

Make Ready for Dismantling of the Main Bearing

1)Dismount crankcase covers in front and opposite the bearing concerned.

2)Turn the engine until the crank is in a convenient position for carrying out the work.

3)Dismount the bracing screw (side screw).

4)Mount the hydraulic tools and loosen the main bearing stud nuts. For operation of the hydraulic tools, see working card 520-01.05.

Fig 1. Mounting of Hydraulic Tools.

5) Dismount the hydraulic tools and slacken the nuts somewhat.

Dismantling of the Main Bearing Cap

6) Fit the eye screws, diagonally, in the threaded holes in the main bearing cap, see fig 2.

Pass the wire supplied through the eye screw and attach it as shown, so as to keep the bearing cap in place when the main bearing stud nuts are removed.

7) Work the main bearing cap loose from the engine frame with a lead hammer or similar.

Fig 2. Mounting of Wire Straps.

8)Lift the main bearing cap a little and unscrew the bearing stud nut.

9)Fit guide tubes on the threads of the bearing studs and lower the bearing cap to make it rest on the collar of the guide tubes.

Dismantling of the Main Bearing Shells

10)Remove the locking piece from the bearing cap and take out the bearing shell.

11)Fit the tool for upper main bearing, for dismantling of upper main bearing shell, in the lubricating hole in the crankshaft and turn out the upper bearing shell by turning the crankshaft, see fig 3.

Tool for upper main bearing

Fig 3. Mounting of tool for upper main bearing.

08028-0D/H5250/94.08.12

Cleaning

12) Clean all machined surfaces, on frame, bearing cap, stud, nuts and bearing shells.

Inspection of Main Bearing Shells

13) Inspect the main bearing shells according to working card 506-01.16.

Note: The bearing is marked according to size and when replaced it must be by a new bearing of the same size.

Mounting of the Main Bearing Shells

14)Push the upper bearing shell as far into position as possible.

15)Fit the tool for upper main bearing in the lubricating hole in the crankshaft and turn in the upper bearing shell by turning the crankshaft.

Make sure that the shell enters its correct position then remove the tool for upper main bearing.

L23/30H

16)Lubricate the end of the bearing shells with molycote pasta or similar.

17)Insert the lower bearing shell in the bearing cap and mount the locking piece.

Lubricate the bearing shell and journal with clean lubricating oil.

Mounting of the Main Bearing Cap

18) Raise the bearing cap into position, dismount the guide tubes, coat the bearing studs with molycote pasta or similar and fit the bearing stud nuts.

Make sure that the bearing cap and bearing shell are in their correct position.

19)Dismantle the wire straps.

20)Mount the hydraulic tools, see working card 520-01.05, and tighten the nuts as prescribed on page 500-40.

21)Coat the back side of the bracing screws' (side screws') hexagonal head with a thin coat of silastene or similar.

22)Mount the screws and tighten with a torque spanner as indicated on page 500.40.

08028-0D/H5250/94.08.12

Fig 1. Mounting of Hydraulic Tools.

5) Dismount the hydraulic tools and slacken the nuts somewhat.

Dismantling of the Guide Bearing Cap

6) Fit the eye screws, diagonally, in the threaded holes in the guide bearing cap, see fig 2.

Pass the wire supplied through the eye screw and attach it as shown, so as to keep the bearing cap in place when the guide bearing stud nuts are removed.

7)Work the guide bearing cap loose from the engine frame with a lead hammer or similar.

8)Lift the guide bearing cap a little and unscrew the bearing stud nut.

Fig 2. Mounting of Wire Straps.

9) Fit guide tubes on the threads of the bearing studs and lower the bearing cap to make it rest on the collar of the guide tubes.

Dismantling of the Guide Bearing Shells

10) Remove the locking piece from the bearing cap and take out the bearing shell.

The thrust washer of the guide bearing is partially countersunk into the engine frame and attached by means of four screwed-on clamps which are visible after lowering the bearing cap, see fig 3.

Thrust washer

Fig 3. Guide Bearing with Thrust Washer.

11) Unscrew the clamps and push out the thrust washers.

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

Fig 4. Dismounting of Upper Shell.

12) Theupperbearingshellisdismountedbymeans of special tool see fig 4.

Cleaning of Components

13) Clean all machined surfaces, on frame, bearing cap, stud, nuts and bearing shells.

Inspection of Guide Bearing Shells

14) Inspect the guide bearing shells according to working card 506-01.16.

Mounting of the Guide Bearing Shells

The bearing shells of the guide bearing, which are identical to those of the main bearings, are narrower than the bore for the guide bearing and it is therefore essential that the shells are positioned perfectly correct in the bore.

For this purpose a guide tool is supplied for positioning on the engine frame when the upper bearing shell is to be fitted, see fig 5.

15)Push the bearing shell into correct position through this guide tool, by using tool item 202, if necessary use a plastic hammer.

16)Fit the thrust washers and clamps.

Guide for mounting of upper shell.

Fig 5. Mounting of Upper Shell in Guide Bearing.

Note: Clearance in guide bearing axially, see page 500.35.

17)Lubricate the end of the bearing shells with molycote pasta or similar.

18)Insert the lower bearing shell in the bearing cap, and mount the locking piece.

Mounting of Guide Bearing Cap

Lubricate the bearing shell and journal with clean lubricating oil.

19) Raise the bearing cap into position, dismount the guide tubes, coat the bearing stud with molycote pasta or similar and fit the bearing stud nuts.

Make sure that the thrust washers, bearing shell and bearing cap are in their correct position.

20)Dismantle the wire straps.

21)Mount the hydraulic tools, see working card 520-01.05, and tighten the nuts as prescribed on page 500-40.

22)Coat the back side of the bracing screws' (side screws') hexagonal head with a thin coat of silastene or similar.

23)Mountthescrewsandtightenwithatorquespanner as indicated on page 500.40.

Working Card

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L23/30H

08028-0D/H5250/94.08.12

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