Stripping Down An Engine (as from 3 cylinder engine)
Secure engine in swivelling mounting stand.
1. Dismantle the following units and components: Air filter with holder, starter, air compressor with bracket and lubricating oil line, generator with holder, fuel-supply line to the flame-type heater plug or the pipe connecting with the pilot injector, induction manifold, exhaust manifold, cover plate on the exit air side, air cowling, fuel and lubricating oil filters with their supply lines, leak-off and delivery lines, vertical plate on the fly-wheel side, blower, front vertical plate, oil cooler, air cowling, vee-belt idler.
NOTE: Immediately fuel line unions are dismantled plug or fit caps on the connecting stubs and pipe ends.
2. Dismantle the vee-belt pulley for the air compressor, main belt pulley and front cover. (Use retainer for vee-belt pulley, No. 143400).
NOTE: The screw securing the vee-belt pulley has a left-hand thread.
3. Disassemble the nut on the fuel-injection pump's driving shaft. (Use the universal device No. 110340 or a 19 mm socket spanner).
As from 1975, the hub was modified in the case of rigid drive. (The thread for attachment of tool No. 110340 with sleeve has been omitted). Remove gear-wheel fastening screws. (See Section 7)
4. Mount the tool without sleeve if the pump drive has on injection timer. If it has no injection timer mount the tool with sleeve (Universal device No. 110340).
5. Pull the injection pump drive from the pump shaft. Dismantle the pump and the securing flange.
6. Dismantle the injectors, upper cover plate, valve covers and rocker arm shaft brackets, remove the push-rods and unscrew the plugs. (Use socket spanner No. 120040, square socket insert No. 120060)
Fig. 9-18, left
7. Slacken the cylinder head studs in stages, in diagonal sequence. (Use socket spanner No. 120040)
Fig. 9-18, right
8. Dismantle the cylinder heads and pushrod sheaths.
9. Turn engine upside down. Dismantle the sump with sheet-metal partition, crankcase breather and oil strainer. Disassemble the big-end bearing bolts. (Use bent socket spanner No. 131540)
10. Slacken and remove the big-end bearing caps. Withdraw the cylinders with pistons and connecting rods from the crankcase. Remove the halves of bearing shells and mark them on the back corresponding to the connecting rods with an electric scriber.
NOTE: Make sure that the bearing shells do not get damaged.
11. Dismantle the oil pump and idler gear, camshaft and tappets, flywheel and main bearing caps.
12. Remove the crankshaft and the halves of bearing shells. Mark the bearing shells on the back corresponding to the crankcase with an electric scriber. Unscrew the plugs, oil feeders and oil injection nozzles from the crankcase. Clean all parts and thouroughly wash out the oilways.
NOTE: Remove horizontal oil nozzles. Fig. 9-20
13. Check all parts for suitability for reuse.
Assembling The Crankshaft Assembly (as from 3 cylinder engine)
NOTE: It is assumed that the liner is fitted in the front camshaft bearing bore.
1. Place the crankcase with the cylinder head joint face downwards. Screw the dosing plugs in the oilways of the bearing webs.
2. Assemble the screwed sealing plugs, fitted with new gaskets, in the oilholes connecting with the bearing webs.
NOTE: If the engine is to be fitted with an air compressor no plug should be assembled in the third hole viewed from the front plate.
3. If the engine is not to be equipped with a hydraulic pump, the core-hole cover plate should be flush-mounted with jointing compound. Then assemble a screwed plug, fitted with a new gasket, to seal the tapped hole in the side of the crankcase.
4. Replace missing or damaged locating sleeves in the joint face. Check the baffle and renew, if necessary.
5. Replace missing or damaged locating sleeve for the journal of the idler gearwheel. The dividing point must face in the direction of the cylinder head joint surface. Assemble the screwed plugs, fitted with a new gasket, in the main oil gallery on the near side of the engine.
6. Replace missing or damaged dipstick guide. Drive it in so that it seats.
7. Assemble the screwed plugs, fitted with a new gasket, in the main oil gallery on the far side.
8. Fit the cover plate to the flywheel end of the camshaft bore. Apply jointing compound and caulk. (Use pressin device No. 143610).
9. Screw the oil nozzles, fitted with lock washers, in the bearing webs.
9.1.1. Install new oil nozzle in tool No. 151100 as shown (side with long slot), the dowel pin pointing toward the cylinder head (arrow).
9.1.2. Install oil nozzle properly located (arrow).
NOTE: Before installation fill annular groove with sealant.
10. Oil the tappets and fit them in the crankcase.
11. Assemble the thrust washer to the camshaft, (see arrow). Oil the camshaft journals. Install the camshaft in the bearing bores.
Fig. 9-70, left
NOTE: On recent engines place compression spring on camshaft journal.
Fig. 9-70, right
12. Check the locating pin in the crankshaft gearwheel. It should project 17 mm from the side opposite that bearing the identification mark. If necessary, fit a new locating pin or correct the position of the existing one.
13. Fit the crankshaft gearwheel, with the face bearing the identification mark directed away from the crankshaft. If necessary, drive it on.
14. Install the halves of bearing shells in the crankcase and bearing cap, making sure that the identification marks are correct.
15. Coat the thrust ring halves with grease and stick them by their smooth faces to the first bearing web and first bearing cap.
NOTE: A locating pin must be fitted in either side of the bearing cap. The halves of thrust ring should locate against these pins.
16. Oil the crankshaft journals and install the crankshaft.
17. A centring sleeve must seat in the main bearing cap and bearing web.
18. The bearing cap must be fitted with its identification number corresponding to and in the same direction as that stamped on the crankcase.
19. Assemble the bolts in the bearing caps. Tighten and lock down in accordance with the instructions for tightening bolts and studs. (Use device No. 101910)
NOTE: Start by tightening the middle bearing cap and those on either side, finishing with the bearing caps at the ends. The crankshaft must be able to rotate freely.
20. Push the crankshaft towards left front end of the engine and measure the end clearance at bearing 1.
Fig. 9-76, left
21. The end clearance of the crankshaft must be within the limits laid down in the specifications. If it is not, dismantle bearing cap 1, remove the halves of thrust ring and fit suitable new thrust ring halves with their smooth faces against the bearing web and bearing cap.
Fig. 9-76, right
22. Fit a new rubber O-seal on the flange of the fuel-injection pump.
23. Mount the injection pump.
24. Check the Woodruff key in the injection pump shaft. Fit a new one if necessary.
25. Install the injection pump drive with the keyway in alignment with the Woodruff key.
26. Assemble and lock down the nut on the injection pump drive in accordance with the instructions for tightening bolts and studs. (Double spanner No. 110340 resp. 13, 19 mm socket spanner.)
Fig. 9-79, left and right
27.1 Check the journal for the idler gear. If it is damaged, renew it.
27.2 Measure the diameter of the journal.
27.3 With a micrometer set the internal dial indicator set to the diameter of the journal.
27.4 Check the idler gear. If it is damaged fit a new one.
27.5. Measure the bearing bore of the idler gear.
27.6. The dial gauge will indicate the vertical clearance. This must not exceed the permissible maximum given in the specifications. If necessary, renew the bearing bushing in the idler gear and the journal.
27.7. Press out of the idler gear the bearing bushing that is to be renewed.
27.8. Renew bearing bushing and see that it is squarely seated.
28. After inserting the dowel sleeve (arrow), insert the journal for the idler gear, and oil.
29. Position the gearwheels with the marks lined up and install the idler gear. Note that the mark on the injection pump gearwheel differs from one type of engine to another.
30. F3L: The reference mark on the injection pump gearwheel of this model is a figure 3 with a dot above it.
31. F4/5/6L: Engines of these types have a dot to mark the mating point of the injection pump gearwheel.
NOTE: Pay attention to modified marks on camshaft and injection pump gears.
32. Fit a new rubber O-seal on the discharge pipe of the oil pump.
33. Position the oil pump and pipe on the crankcase and tighten the oil pump screws. Adjust the gear flank clearance to the value stated in the specifications.
NOTE: The manufacturing material for the bolts fastening the lube oil pump has been changed from 8.8 to 10.9. Instead of the split lockwashers, domed lockwashers are to be used. The two washers on the fastening bolts at the oil deflector for F5/6L 912 remain unchanged. The tightening torque for all the fastening bolts is: 35 Nm.
34. Tighten and lock down the stud securing the idler gear mounting (on the oil delivery pipe clip), in accordance with the instructions for tightening bolts and studs.
35. Connect the suction pipe to the oil pump.
36. Disassemble the camshaft's screwed check plug in the front cover.
NOTE: On recent engines place stop cap on camshaft journal and push against spring.
37. Fit a new gasket to the front cover, stick it in position with grease and mount the cover.
38. Press the camshaft towards the flywheel end and measure the distance from the end face of the camshaft to the sealing surface of the check plug.
NOTE: Gauging as described refers to older engines only.
39. Measure the distance from the end face to the contact surface of the check plug.
40. Deduct the distance from the end face to the contact surface of the check plug from the distance between the end clearance of the camshaft. The value must be that stated in the specifications. Select suitable seal rings.
41. Assemble the check plug fitted with the repective seal rings.
Fitting Tachometer Drive At Camshaft (Angle Drive)
Fig. 9-91 shows the mounting of the angle drive.
42.1 Press the camshaft towards the flywheel end and measure the distance from the end face of the camshaft to the sealing surface at the front cover.
42.2 Measure the distance from stop face of stop union to sealing surface of stop union. (Dimension "b")
(Cf. Fig. 9-90)
42.3 Dimension "a" minus dimension "b" gives the end clearance "X" of the camshaft. This value must agree with that stated in the Specification Data. Select shims accordingly.
42.4 Screw in the stop union (3) together with the respective shims (4) and tighten up.
42.5 Screw in angle drive (1) until it contacts ring (5). Do not yet tighten lock nut (2).
42.6 Fasten flexible shaft (6) to angle drive. (Check whether flexible shaft is sufficiently clear of vee-belt pulley.)
42.7 Mount bracket and tachometer at the point provided.
42.8 Insert drive tongue of flexible shaft (provided with grease) and connect to tachometer.
42.9 Tighten lock nut (2) of angle drive.
43. Grease the lip of the radial packing ring in the front cover and the contact surface of the vee-belt pulley. Install the vee-belt pulley, having brought the locating hole into alignment with the locating pin in the crankshaft gearwheel.
44. Assemble (left-hand threaded) screw, tighten and lock down in accordance with the instructions for tightening bolts and studs. (Use retainer for vee-belt pulley No. 143400, angle-of-turn indicator No. 101910).
45. If the engine is fitted with an air compressor, mount the vee-belt pulley therefor.
46. Mount a new rubber O-seal on the shoulder of the vee-belt idler or cover.
47. Mount the vee-belt idler or cover.
48. If the engine is fitted with a warning system for vee-belt breakage, i.e. blower inoperative, also mount the holder of the warning switch. Install spacer sleeve between the holder and front cover.
49. With a straight-edge, check the vee-belt idler and pulley for alignment.
50. If necessary, add or remove washers between the vee-belt idler and tension lever to bring the vee-belt idler into alignment with the vee-belt pulley.
51. Slightly grease the contact surface of the radial packing ring on the crankshaft and the lip of the radial packing ring in the back cover.
52. By means of grease, stick the new gasket to the back cover. Mount the cover so that it is flush with the contact surface of the oil sump.
NOTE: Check the contact surface of the radial packing ring. If the shaft exhibits a groove, change the position of the radial packing ring in the back cover.
53. Trim off the edges of the front and back cover gaskets projecting beyond the joint in the back cover.
54. Mount the flywheel after having aligned the locating hole to suit the heavy-duty clamping sleeve of the crankshaft.
55. Position the vee-belt pulley on the crankshaft. (Use retainer for vee-belt pulley No. 143400).
56. Tighten and lock down in diagonal sequence the flywheel securing studs in accordance with the instructions for tightening bolts and studs. (Use angle-of-turn indicator No. 101910).
Assembling The Cylinder Unit
1. Fit a circlip in the piston for the location of the gudgeon pin.
2. Heat piston with the piston heating device No. 139000 (temperature approx. 80° C). Oil the gudgeon pin and gudgeon-pin bush. Secure the opposite end of the gudgeon pin in position. Place the piston on the small end of the connecting rod so that the exhaust air side of the piston (marked on the piston crown) is in the same direction as the open side of the connecting-rod bearing. Force in the gudgeon pin.
3. Fit the second circlip in the piston for the location of the gudgeon pin. Oil the working surface of the cylinder and the piston. Fit the piston rings so that their gaps are equally spaced round the piston.
4. Mount the piston ring sqeezer and tension. Position the piston so that its exhaust air side is on that side of the cylinder recessed for the tappet covers. (Use piston ring compressing device 130530)
5. Adhere to cylinder, by means of grease, 2 shims of 0.2 mm each.
6. Apply grease to a new rubber O-seal and fit in groove of cylinder.
NOTE: On later version, the rubber O-seal is omitted. Fitted instead is an aluminium-plated steel compensation ring of 0,2 mm thickness.
7. Fit the halves of bearing shells in the correspondingly marked connecting rod and bearing cap.
8. As from 3 cylinder engine turn the crankcase on the injection pump side.
9. Install the cylinder, piston and connecting rod assembly so that the exhaust air side of the piston faces the tappet bores.
10. Oil the crankpin. Place the big-end bearing on the crankpin.
NOTE: When rotating the crankshaft make sure that the cylinders do not lift from the contacting surface.
11. Assemble the mating cap on the big-end bearing. Fit new big end bolts; tighten and lock down in accordance with the instructions for tightening bolts and studs. (Use angle-of-turn indicator No. 101910).
12. Position the engine so that the cylinders are vertical, facing upwards.
13. Bring the cylinders into alignment.
14. Coat with grease a piece of 2 mm gauge lead wire and stick it at right-angles to the centre line of the engine on the piston crown.
15. Mount the cylinder head. Measure the length of the cylinder head studs.
16. Renew those cylinder head studs that have stretched beyond the limits stated in the specification.
17. Assemble the studs fitted with washers and slightly tighten. Bring the inlet and exhaust flanges of the cylinder heads into alignment, making sure that in so doing the cylinders do not get out of alignment.
18. Preload bolts by above wrench through 30 Nm (see tightening procedure) and tighten through one stage (45°) with the aid of device No. 101900.
19. Turn the crankshaft through 360° in the direction of engine rotation. Undo the cylinder head and remove the piece of lead wire. Measure the thinnest part of the squeezed wire.
For piston crown clearances see Technical Data.
20. Adjust clearance by shims of 0,2 mm and 0,5 mm.
Note for Refitment:
This is the easiest method of getting the correct clearance:
If the clearance is too small, remove cylinder and place the number of shims required below the cylinder.
If the clearance is too large, raise cylinder, cut through the surplus shims with side-cutting pliers and remove. (Fig. 9-115).
21. Remount the cylinder head.
22. Screw plugs fitted with new gaskets into the holes for the cylinder head studs. (Use socket spanner No. 120040 and square-socket insert No. 120060).
23. Assemble and tension the spring (Spring compressing tool No. 125300).
Fig. 9-117, left
24. Place on the profile washer with the domed side facing towards the spring. Fit a new sealing ring with the flat side facing towards the end of the pushrod tube.
Fig. 9-117, left
25. At the opposite end of the tube, fit a new sealing ring with the flat side facing towards the shoulder.
Fig. 9-117, right
26. Insert the two pushrod sheaths, spring end first, in the tappet bore in the crankcase and locate the upper end with the gasket in the cone of the cylinder head. Withdraw the spring tensioner.
27. Assemble the pushrods and mount the rocker arm shaft support.
28. Adjust the valve clearance.
29. Stick new gasket with sealing compound to rocker chamber cover. Position cover, align and fit bolt with new washer. Tightening see Specification Data.
30. Install injector with new washer plus heat guard (FL 912 W) in cylinder head. Tighten bolts as under Specification Data. Install thrust piece and place stirrup in position. Place washer with convex side facing stirrup and screw on nut. (See Specification Data).
Assembling An Engine Complete (as from 3 cylinder engine)
1. Turn the engine over so that the cylinders face downwards.
2. Apply grease to a new gasket and stick it in position on the sump. Assemble the sump.
3. Install intermediate bottom plate fitted with a second gasket. (Applies to F6L with sheet-steel sump only).
4. Install the breather pipe, to which jointing compound has been applied, so that it seats on the shoulder of the crankcase.
5. Assemble screw to secure end plate of crankcase breather to the oil sump.
6. Turn the engine over so that the cylinders are in the upward vertical position.
7. Secure front vertical plate to cylinder. Secure fuel pipe for flame-type heater plug by clip.
8. Position air cowling base, screw in central bolt and fit two washers. (Example: F5L)
9. Install the oil cooler fitted with a a new rubber O-ring to seal against the lower part of the air cowling. Tighten the pipe unions.
10. Fit bolts with washers for oil cooler.
11. Secure exhaust air baffle.
12. Fit rear vertical plate.
13. Fit cooling blower to front-end cover.
14. Position the upper cover plate on the cylinder heads.
15. Connect fuel delivery lines, fitting new rubber mounting strip and new rubber sleeves.
16. Connect the leak-off lines between the injectors and from one of the injectors to the injection pump. Assemble the long hollow screw in cylinder 1 and plug it to prevent the ingress of dirt.
17. If the engine has a flame-type heater system, mount the solenoid valve on the front vertical plate.
18. Install bracket mounting new fuel and lubricating oil filters and connect the fuel lines, fitting new gaskets.
18.1. See Fig. 9-145 for F3L.
18.2. See Fig. 9-146 for F4/6L.
19. Install temperature sensors/contactors in cylinder heads. Starting Fig. 9-147 the following notes are applicable.
NOTE: Sensor and contactor differ by their length. Fig. 9-148 shows sensor at left and contactor at right.
The direct-injection (D) and two-stage combustion (W) engines have contact makers (switches) of different temperature limits:
- D = 150° CW = 170° C
NOTE: Cylinder numbering.
The temperature sensor is secured to pickup point 1. A second sensor or a contactor is secured to point 2.
20. Hook in the air cowling at the top and close at the bottom.
21. Fit a new gasket in the oil filler cap. Replace the rubber gasket by a cork gasket.
22. Close the oil filler; insert oil dipstick.
23. Where an extra-long oil filler neck and dipstick guide have been provided, install filler neck with new O-ring in front-end cover and secure to cooling blower. Install dipstick guide.
24. If the engine is fitted with an air compressor the oil return hole in the front cover plate must be left open. If the engine is not fitted with an air compressor a plug coated with jointing compound should be screwed into the oil return hole.
NOTE: The next three operations apply only if the engine is fitted with an air compressor.
25. Coat a new rubber O-seal with grease and stick it in position on the bracket of the air compressor.
26. Mount the air compressor with bracket on the front cover plate.
27. Install the high-pressure oil line, fitted with new gaskets, running from the oil gallery to the air compressor and tighten the female screws.
28. Install new gaskets for the induction and exhaust manifolds with the flat end upwards.
NOTE: On engines of more recent design, fit in any case modified seals to intake pipe. These seals must not be used on the exhaust manifold. New gasket design see Fig. 9-157 (arrows).
29. Mount the induction manifold.
30. Fit the washers and assemble the nuts.
31. Connect the induction pipe, fitted with a new gasket, to the air compressor. In so doing, pay attention to the retaining cone.
32. If the engine is of the F6L type, check the gaskets of the exhaust manifold. They sould seat freely in the groove and be under tension. If necessary, renew them.
33. Install the exhaust manifold.
34. Fit the washers and assemble the tall brass nuts.
35. If the engine has a flame-type heater system, install the pipe, fitted with new gaskets, connecting the solenoid valve with the heater.
Fitting The Generator
36. Mount bracket.
NOTE: Adjust any misalignment of belt pulleys by washers under the bolts.
37. Secure strap, position generator and check alignment between generator and crankshaft pulleys.
38. Install belt at minimum distance of pulley.
39. Tension belt so that thumb pressure applied to the longest accesible length will cause 10 - 15 mm deflection.
40. Adjust belt tension by swinging generator outwards. Tighten strap bolt.
41. Fit starter motor and, where required, air cleaner.
Marks On Timing Gear Train (F2L 912)
Marks On Camshaft Gear (F3/4/5/6L 912)
Marks On Injection Pump Gear (F3L 912)
Gearing Layout (F3L 912)
Gearing Layout (F4/5/6L 912, B/FL 913)