engine - toro · pdf fileengine removal. engine 4b-2 rev. 000 tx420, tx425 series service...

4B-1TX420, TX425 Series Service Manual Rev. 001

ENGINE

TX420 & 425 250000401 & up

Note: Protect all exposed sealing areas and open cavities from damage and foreign material and chemicals

1. Remove the rear access cover (Fig. 0136).

Fig 0136 PICT-1026

2. Using a 1/2” socket and wrench, remove the battery clamp (Fig. 0137).

Fig 0137 PICT-1029

3. Using a 1/2” socket, disconnect the negative and then the positive battery cable (Fig. 0138).

Fig 0138 PICT-1033

Fig 0139 PICT-1034a

4. Remove the battery from the battery mounting tray (Fig. 0139).

Engine Removal

ENGINE

4B-2 Rev. 001 TX420, TX425 Series Service Manual

6. Using a 3/8” socket, remove the right and left hand rear cover support assemblies (Fig. 0141).

Fig 0141 PICT-1037

7. Using 3/4” and 9/16” sockets, remove the rear chassis cover by removing the 8 sets of bolts and nuts that retain it (Fig. 0142).

Fig 0142 PICT-1040a

Fig 0143 PICT-0555

8. Disconnect the 2 wires on the fuel sending unit located on top of the fuel tank (Fig. 0143).

A. Center terminal B. Outside terminal orange wire black wire

A B

Fig 0140 DSC-3408

5. Using a 3/4” socket, remove the right and left counterweights (Fig. 0140).

ENGINE


Fig 0144 PICT-1041a

9. Remove the fuel line hose clamp and fuel line from the tank. Slide the fuel tank out of the rear of the frame (Fig. 0144).

10. Place a drain pan under the left rear of the unit and, using a 11/16” socket, remove the engine oil drain plug and drain the engine oil (Fig. 0145).

Fig 0145 PICT-1496

11. Label the hydraulic hard lines and engine bulkhead plate A, B, and C as shown:A. Gear pump to the 2 spool valve (Fig. 0146).

Fig 0146 PICT-1497a

Fig 0147 PICT-1498a

B. Gear pump to the auxiliary valve (Fig. 0147).

ENGINE


12. Using a 15/16” wrench, disconnect the hydraulic line marked “A” (gear pump to the 2 spool valve) and cap to prevent debris from entering the system (Fig. 0149).

Fig 0149 PICT-1500

13. Using a 1-1/8” wrench, disconnect the hydraulic line marked “B” (gear pump to the auxiliary valve) and cap to prevent debris from entering the system (Fig. 0150).

Fig 0150 PICT-1502

Fig 0151 PICT-1503a

14. Using a 1-1/8” wrench, disconnect the hydraulic line marked “C” (hydraulic oil cooler) and cap to prevent debris from entering the system (Fig. 0151).

Fig 0148 PICT-1499

C. Hydraulic oil cooler (Fig. 0148).

ENGINE


Fig 0152 PICT-1504

15. Using a 1/4” socket, loosen the hose clamp securing the engine oil drain line to the frame. Disconnect the engine oil drain line from the frame (Fig. 0152).

Note: Cap the engine oil drain hose so that debris does not enter the system.

16. Raise the hood and secure in the upright position with the hood prop rod.

17. Remove the left and right side engine guards (Fig. 0153).

Fig 0153 PICT-1506

Fig 0155 PICT-1508

E. oil cooler inlet (Fig. 0155).

Fig 0154 PICT-1507

18. Mark the two oil cooler lines as shown:D. Oil cooler outlet (Fig. 0154).

ENGINE


19. Using a 1-1/8” wrench, disconnect the hydraulic oil cooler outlet line (marked with a D) from the oil cooler (Fig. 0156).

Fig 0156 PICT-1511

20. Using a 1-1/8” wrench, disconnect the hydraulic oil cooler inlet line (marked with an E) from the oil cooler (Fig. 0157).

Note: Cap the hydraulic lines so debris does not enter the system.

Fig 0157 PICT-1512 Fig 0159 PICT-1515

22. Using a 3/4” socket and wrench, loosen 2 of the 4 fasteners on one side of the counterweight. Support the weight and remove the other 2 fasteners. Remove the front counterweight and the remaining bolts, washers and nuts (Fig. 0159).

Fig 0158 PICT-1514

21. Using a 9/16” socket and wrench, remove the bolt and nut that secures the breather vent to the oil cooler bracket (Fig. 0158).

ENGINE


23. Using a 1/2” socket, remove the two sets of carriage bolts, washers and nuts holding the muffler heat shield onto the front grill (Fig. 0160). Remove the heat shield.

Fig 0160 PICT-1517

24. Raise the loader arm at least 12” (30.48cm) off the floor and support the quick attach assembly with jack stands (Fig. 0161).

Fig 0161 PICT-1520a

Fig 0163 PICT-1521a

26. Lift the grill and oil cooler off the frame (Fig. 0163).

Fig 0162 PICT-1518

25. Using a 1/2” socket, remove the 4 self-tapping bolts that hold the front grill to the frame (Fig. 0162).

ENGINE


27. Using a spring removal tool (Toro P/N 92-5771) connect the tool to the spring end located on the stud bolted to the tower assembly. Pull up on the spring end to remove the spring from the bolt stud (Fig. 0164).

Fig 0164 DSC-0589

28. Remove the spring from the idler arm (Fig. 0165).

Fig 0165 DSC-0590

Fig 0167 DSC-3429

30. Using a 5/16” socket, remove the cable clamp and disconnect the choke cable from the choke linkage (Fig. 0167).

Fig 0166 PICT-1522

29. Remove the belt from the pulleys (Fig. 0166).

ENGINE


31. Using a 5/16” socket, remove cable clamp and disconnect the throttle cable from the throttle linkage (Fig. 0168).

Fig 0168 DSC-3430

32. Slide the choke and throttle cables from the left side of the engine baffle (Fig. 0169).

Fig 0169 PICT-1523 Fig 0171 PICT-1525

34. Mark the hydraulic oil cooler return line with the letter G on the nut and on the fitting leading to the hydraulic oil tank (Fig. 0171).

Fig 0170 PICT-1524

33. Mark the hydraulic oil return line (coming from the filter) with the letter F on the nut and on the fitting leading to the hydraulic oil tank (Fig. 0170).

ENGINE


35. Using a 1-3/8” wrench, disconnect the hydraulic line marked F from the tank fitting also marked F (Fig. 0172).

Fig 0172 PICT-1526

36. Using a 1-5/8” wrench, disconnect the hydraulic line marked G from the tank fitting also marked G (Fig. 0173).

Note: Capallhydrauliclinesandfittingssothatdebris does not enter the system.

Fig 0173 PICT-1527 Fig 0175 PICT-1529

38. Using a 15/16” wrench, disconnect the hydraulic oil case drain line from the hydraulic oil tank fitting (both are marked with the letter H) (Fig. 0175).

Note: Capthehydrauliclineandfittingsothatdebris does not enter the system.

Fig 0174 PICT-1528

37. Mark the hydraulic oil case drain line nut and tank fitting with the letter H (Fig. 0174).

ENGINE


39. Pull the hydraulic case drain hose from the reservoir tank out from the rear of the unit (Fig. 0176).

Fig 0176 PICT-1531

40. Using a 5/16” socket, loosen the two hose clamps on the two hydraulic suction hoses located on the hydraulic tandem pump (Fig. 0177).

Fig 0177 PICT-1533 Fig 0179 PICT-1538

42. Using a 13mm socket, remove the bolt that secures the engine grounding wire and battery negative cable located below the engine starter on the right side of the engine (Fig. 0179).

Fig 0178 PICT-1534

41. Disconnect the two suction hoses from the hydraulic tandem pump fittings (Fig. 0178).

ENGINE


43. Disconnect the temperature sensor connector from the harness (Fig. 0180).

Fig 0180 PICT-1539

44. Pull back the red boot and, using a 1/2” socket, remove the nut that secures the light blue wire and red positive battery cable to the starter solenoid post. Remove the light blue wire and red positive battery cable from the post and replace the nut (Fig. 0181).

Fig 0181 PICT-1543

Fig 0183 PICT-1545

46. Disconnect the engine harness connector located above the starter solenoid (Fig. 0183).

Fig 0182 PICT-1544

45. Disconnect the dark blue wire spade plug from the starter (Fig. 0182).

ENGINE


47. Cut the cable tie securing the white hour/tachometer wire and unwrap from the spark plug wire (Fig. 0184).

Fig 0184 PICT-1546

48. Cut the cable tie holding the wire harness and battery cables to the oil cooler hydraulic line (Fig. 0185).

Fig 0185 PICT-0629a

Fig 0187 PICT-1554

51. Using a 1-5/8” wrench, remove the hydraulic tank return line T-fitting (Fig. 0187).

Fig 0186 PICT-1549

49. From the rear of the unit, pull the wire harness out through the engine baffle.

50. Using a 1/2” socket, loosen the muffler clamp located between the muffler and the manifold pipe (Fig. 0186).

ENGINE


52. Attach chains and straps to the engine lift hooks. Attach a hoist to the chains and apply tension to the chains/straps (Fig. 0188).

Fig 0188 PICT-1550

53. Using a 9/16” socket and wrench, remove all 4 nuts from the carriage bolts securing the engine plate to the frame (only 2 bolts and nuts shown) (Fig. 0189).

Fig 0189 PICT-1558a Fig 0191 PICT-1562

56. Carefully raise the engine out of the frame (Fig. 0191).

57. For engine service, refer to the proper Kohler service manual.

Fig 0190 PICT-1559

54. Remove all 4 carriage bolts holding the engine plate to the frame.

55. Slide the engine to the rear of the machine and slide the muffler off the manifold (Fig. 0190).

ENGINE


TX420 & 425 250000401 & up

Note: Protect all exposed sealing areas and open cavities from damage and foreign material and chemicals.

1. With the engine attached by chains or straps to a hoist, start lowering the engine down to the frame.

2. While lowering the engine into place, slide the muffler onto the manifold (Fig. 0192).

Fig 0192 PICT-1559

Fig 0194 PICT-1554

4. Remove the chains/straps and hoist from the engine.

5. Using a 1-5/8” wrench, install the hydraulic tank return line T-fitting (Fig. 0194).

Fig 0193 PICT-1558a

3. With the engine plate setting in the frame, install the 4 carriage bolts and nuts that secure the engine plate to the frame (only 2 bolts and nuts shown) (Fig. 0193).Engine Installation

ENGINE


6. Using a 1/2” socket, install the muffler clamp to secure the muffler to the manifold (Fig. 0195).

9. Note: The installation of the engine grounding wires is: bolt, star washer, battery negative cable, ground wires (three wires on a ring terminal), and a star washer (Fig. 0197).

Fig 0195 PICT-1549

Fig 0197 PICT-0808a

10. Wrap the tachometer wire 5 times around the right side spark plug wire (Fig. 0198).

7. From the rear of the machine, feed the wire harness through the engine baffle to the right side of the engine.

8. Using a 13mm socket, install the engine grounding wires and battery negative cable locates below the engine starter on the right side of the engine (Fig. 0196).

Fig 0198 PICT-1563

Fig 0196 DSC-0814

ENGINE


11. Install a cable tie around the two ends of the wrapped tachometer wire (Fig. 0199).

Note: Ensure that the wrapped portion and the tail of the tachometer wire are secured tightly to each other with the cable tie.

Fig 0199 PICT-1564

12. Connect the engine harness connector located above the starter to the wire harness connector (Fig. 0200).

Fig 0200 PICT-1545

Fig 0202 PICT-1543

14. Connect the light blue wire and red positive battery cable to the starter solenoid post (Fig. 0202).

Fig 0201 PICT-1544

13. Connect the dark blue wire spade plug to the starter (Fig. 0201).

ENGINE


15. Connect the hydraulic oil temperature sensor connector to the wire harness (Fig. 0203).

Fig 0203 PICT-1539

16. Install the two suction hoses to the fittings connected to the tandem hydraulic pump (Fig. 0204).

Fig 0204 PICT-1565

Fig 0206 PICT-1531

18. Feed the case drain hose in through the rear of the machine up along the right side of the engine up to the hydraulic tank fitting marked with an H (Fig. 0206).

Fig 0205 PICT-1566

17. Slide the cable clamps up the suction hoses and, using a 5/16” socket, tighten the hose clamps into place (Fig. 0205).

ENGINE


19. Using a 15/16” wrench, connect the hydraulic oil case drain hose to the hydraulic tank fitting (both marked H) (Fig. 0207).

21. Using a 1-5/8” wrench, connect the hydraulic oil return line to the T-fitting leading to the hydraulic oil tank (both marked with G) (Fig. 0209).

Fig 0209 PICT-1567 Fig 0207 PICT-1529

20. Using a 1-3/8” wrench, connect the hydraulic oil return line coming from the filter to the hydraulic oil tank fitting (both marked with an F) (Fig. 0208).

22. Install the throttle cable into the middle hole on the throttle linkage plate (Fig. 0210)

Fig 0208 PICT-1526 Fig 0210 PICT-1568

ENGINE


23. Move the throttle control lever to the full throttle position and back the throttle control lever off 1/16” (.15cm), this provides for over travel (Fig. 0211).

25. Install the choke cable into the hole in the upper bracket (Fig. 0213).

Fig 0211 PICT-1574 Fig 0213 PICT-1570

26. Move the choke control lever to the “full” choke position and back of the choke control lever 1/16” (.15cm), this provides for over travel (Fig. 0214).

24. Move the throttle linkage to the “full” throttle position and tighten the cable clamp on the linkage (Fig. 0212).

Fig 0214 PICT-1575 Fig 0212 PICT-1569

ENGINE


27. Move the choke linkage to the full choke position and tighten the cable clamp on the linkage (Fig. 0215).

Fig 0215 PICT-1571

28. Route the throttle and choke cables through the left slot on the engine baffle and along the hydraulic line (Fig. 0216).

Fig 0216 PICT-1578 Fig 0218 PICT-1522

30. Install the belt around the crankshaft pulley and the 2 hydrostatic pulleys (Fig. 0218).

Fig 0217 PICT-0830

29. Secure the wire harness and battery cables to the oil cooler hydraulic line just behind the engine baffle (Fig. 0217 – top view).

ENGINE


31. Install the idler spring onto the idler arm assembly and using a spring removal tool (Toro p/n 92-5771) hook the spring onto the stud located on the tower assembly (Fig. 0219).

Fig 0219 PICT-1579

32. Check the alignment of the belt, use a straight edge to check the alignment of the crankshaft pulley and the hydrostatic pulley (Fig. 0220).

Fig 0220 DSC-3518

Fig 0222 PICT-1518

34. Use a 1/2” socket to install the 4 self-tapping bolts to secure the front grill to the frame (Fig. 0222).

33. Place the grill and oil cooler assembly onto the frame (Fig. 0221).

Fig 0221 PICT-1521a

ENGINE


Fig 0223 PICT-1518

35. Using a 1/2” socket, install the 4 self-tapping bolts that hold the front grill to the frame (Fig. 0223).

Fig 0225 PICT-1517

38. Position the front heat shield so that it is placed between the front counterweight and the mainframe. Using a 1/2” socket, install the two sets of carriage bolts, washers and nuts to secure the muffler heat shield onto the front grill (Fig. 0225).

Fig 0226 PICT-1515

Fig 0224 PICT-1667

39. Using a 3/4” socket and wrench, tighten the 4 fasteners securing the front counterweight to the mainframe (Fig. 0226).

36. Lower the loader arm back to the floor.

37. Loosely install the front counterweight (Fig. 0224).

ENGINE


41. Using a 1-1/8” wrench, connect the hydraulic oil cooler inlet line (marked with an E) to the oil cooler (Fig. 0228).

Fig 0228 PICT-1512a

42. Using a 1-1/8” wrench, connect the hydraulic oil cooler outlet line (marked with a D) to the oil cooler (Fig. 0229).

Fig 0229 PICT-1511a

Fig 0230 PICT-1506a

43. Replace the left and right side engine guards (Fig. 0230).

Fig 0227 PICT-1514

40. Using a 9/16” socket and wrench, install the bolt and nut securing the breather vent to the oil cooler bracket (Fig. 0227).

ENGINE


45. Using a 1-1/8” wrench, connect the hydraulic line marked C (hydraulic oil cooler) to the engine bulk-head plate position also marked with a C (Fig. 0232).

Fig 0232 PICT-1503a

46. Using a 1-1/8” wrench, connect the hydraulic line marked B (gear pump to the auxiliary valve) to the engine bulkhead plate position also marked with a B (Fig. 0233).

Fig 0233 PICT-1502

Fig 0234 PICT-1500

47. Using a 15/16” wrench, connect the hydraulic line marked A (gear pump to the 2 spool valve) to the engine bulkhead plate position also marked with an A (Fig. 0234).

Fig 0231 PICT-1504

44. Slide the engine oil drain line on to the fitting on the frame. Slide the hose clamp up and, using a 1/4” socket, tighten the hose clamp into place (Fig. 0231).

ENGINE


Fig 0236 PICT-1715

49. Position the fuel tank behind the machine. Slide the fuel line onto the fuel tank fitting (Fig. 0236).

Fig 0237 PICT-1716

50. Slide the hose clamp down and position it on the hose over the fuel tank fitting (Fig. 0237).

48. Using an 11/16” socket, install the engine oil drain plug into the fitting on the frame (Fig. 0235).

Fig 0235 PICT-1496

51. Raise and securely support the unit. Refer to “Lifting Unit for Service”, page 8-2.

52. Start the unit up and purge the system. Refer to “Purging Air Procedures”, page 12-27.

53. Check the hydraulic lines for any oil leaks.

54. Check the hydraulic reservoir tank and fill if necessary.

ENGINE


Fig 0238 PICT-1718

55. Connect the two wires (black and orange) to the fuel sending unit located on the top of the fuel tank (Fig. 0238).

A. Center terminal B. Outside terminal orange wire black wire

BA

Fig 0240 PICT-1722

58. Using a 3/4” socket, install both rear counterweights (Fig. 0240).

Fig 0239 PICT-1721

56. Slide the fuel tank into the frame.

57. Using 3/4” and 9/16” sockets, install the rear chassis cover with 8 bolts, 2 washers and 8 nuts (Fig. 0239).

Note: The washers are installed on the two bottom bolts.

Note: The rear of the machine may have to be lifted to reposition the jack stands so that the rear chassis cover can be installed.

ENGINE


Fig 0242 PICT-1725

60. Install the rear access cover (Fig. 0242).

61. Lower the machine to the floor.

Fig 0241 PICT-1724

59. Using a 3/8” socket, install the left and right rear cover support panels (Fig. 0241).

engine - toro · pdf fileengine removal. engine 4b-2 rev. 000 tx420, tx425 series service...

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