Upgrading Alternators To Include An Integrated Circuit Regulator{1405, 1410} Caterpillar

Introduction

This instruction provides the necessary information to replace the earlier design discrete component regulator with a new integrated circuit (IC), base plate, diode trio and hardware.

The earlier regulators have separate transistors, diodes and other components mounted on a circuit board covered with an RTV-type coating. Both the new diode trio and the new regulator must be installed to replace this old type of regulator. New mounting holes must be drilled into the alternator housing housing to attach the new components.

Refer to the table "DISCRETE COMPONENT TO INTEGRATED CIRCUIT REGULATOR UPGRADE" for a list of affected part numbers and new replacement part numbers.

Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.

Installation Procedure

1. Hold shaft by placing a 5/16" hex drive in the end recess. Remove shaft nut, washer, pulley, and fan to provide access to the thru bolts.

2. Remove four thru bolts (22) from alternator and separate drive end assembly (with rotor) from rectifier end assembly. This is necessary to allow complete removal of metal shavings that will be created when new holes are drilled.

3. Cover the open end of the rectifier end bearing with tape to keep shavings from getting in the bearing grease.

4. Remove end plate (23) and rectifier cover (24) from rectifier end assembly by removing attaching screws (25).

5. Remove nuts from rectifier bridge terminals and inside of "R" terminal (H) to disconnect three long, identically colored leads to regulator.

NOTE: Some units may have a separate lead between the "R" terminal and a rectifier bridge terminal. If so, remove this lead also.

6. Place nuts loosely back on "R" terminal (H) and on rectifier bridge terminals to hold other leads in place during repair.

NOTE: If old regulator has a sense lead connected to the heat sink attaching screw, remove screw, flat washer and insulator to disconnect lead. Place insulator, washer and heat sink screw loosely back into unit for later attachment of new sense lead.

7. Disconnect two field coil leads from regulator and remove two regulator mounting screws.

8. Lift regulator and long leads with grommet from generator housing.

9. Place new diode trio (1) and regulator base plate (2) in position as shown. Locate base plate (2) by positioning mounting hole (A) over existing mounting hole in casting.

10. Temporarily install the 12.70 mm (.5 in) long mounting screw in hole (A) to hold plate. Align edges to be straight with the sides of the casting.

11. Mark three new hole locations (C, D, and E), then remove diode trio and base plate from housing.

12. Using a 3.6 mm (.14 in) drill bit, drill new holes (C, D, and E) in housing.

NOTE: Holes (C) and (E) will go through housing wall. Hole (D) is positioned in thicker cross section and will not go through. Drill hole (D) 19.1 mm (.75 in) deep, straight into housing material.

13. Remove all traces of metal shavings from both inside and outside of housing when drilling is complete.

14. Place diode trio (1) into position in housing. Coat threads on 12.70 mm (.5 in) long screw (3) with high temperature adhesive/sealant (Locktite® 272, in package).

15. Secure diode trio (1) to housing with screw (3) at mounting hole (E). Tighten screw in newly drilled mounting hole to 3.4 N·m (30 lb in). This is a grounding screw and must be secure.

NOTE: When reinstalling screw in hole previously used, tighten to 3 N·m (26 lb in).

16. Locate heat sink attaching screw (4) for connecting red diode trio lead. Remove screw, flat washer and insulator. Place connector of red lead over hole, then reinstall insulator, flat washer and screw. Tighten screw to 3 N·m (26 lb in)

NOTE: Connector of red lead must be under insulator.

17. Install remaining yellow leads coming out of diode trio (1) on the same side as red lead. Connect each lead to a different rectifier bridge terminal (5), as shown, using three nuts removed and left loosened earlier. Be sure all leads to each of these terminals are properly reconnected. Tighten nuts to 3 N·m (26 lb in).

18. Install remaining yellow lead coming out of diode trio (on same side as blue lead) to inside of "R" terminal (6) with existing attaching nut. Tighten nut to 2.3 N·m (20 lb). Be sure terminal lead does not touch housing after tightening.

NOTE: It may be necessary to hold hex shoulder on outside of terminal as anti-turn while tightening nut.

19. Coat back (metal side) (F) of new regulator (7) with Loctite® 5840 silicone dielectric grease (in package).

20. Place regulator (7) onto base plate (2), aligning three mounting holes (B, C and D).

21. Position blue lead (8) from diode trio (1) and one field coil lead (9) over mounting hole (B) as shown. Insert 25.4 mm (1 in) long insulated screw (10) through regulator (7) and base plate (2) and install nut/lockwasher assembly (11).

22. Making sure the three regulator and base plate mounting holes are still aligned, hold screw (10) at hex cap and tighten nut/lockwasher assembly (11) to 3 N·m (26 lb in).

23. Coat areas (G) on back of base plate (2) (side away from regulator) that will touch rectifier housing with Locktite® 5840, silicone dielectric grease (in package).

24. Coat ends of spacer (12) with the same grease and place spacer over newly drilled mounting hole (C).

25. Place assembled regulator (7) and base plate (2) into housing and align to mounting holes.

NOTE: Blade terminals on regulator must NOT touch alternator housing. Trim ends of terminals if necessary to avoid contact.

26. Install 12.70 mm (.5 in) long screw (13) (in package) to hole (A) in base plate (2) and old mounting hole in housing. Finger tighten at this time.

27. Insert 50.8 mm (2 in) long insulated screw (14) (in package) through the remaining field coil lead (15). Coat threads with high temperature Locktite® 272 adhesive/sealant (in package).

28. Insert screw (14) through regulator (7), base plate (2) and spacer (12) into newly drilled mounting hole (C) and finger tighten. DO NOT get sealant on the surface of the regulator contact.

29. Install 25.4 mm (1 in) long screw (16) (in package) through regulator (7) and base plate (2) and into newly drilled mounting hole (D).

30. Tighten screw in existing Hole (A) to 3 N·m (26 lb in).

31. Tighten screws in newly drilled holes (C) and (D) to 3.4 N·m (30 in). The screw in hole (D) is a grounding screw. Be sure regulator is held securely.

NOTE: Some internal wiring is omitted from illustration for clarity. Unless noted otherwise in instructions, reinstall all other wires to their original locations.

32. Install yellow sense lead (17) loosely to threaded stud (18) on regulator with nut/lockwasher assembly.

33. Route yellow sense lead (17) through grommet to heat sink attaching screw (19).

34. Remove heat sink screw (19), plain washer (20) and insulator (21). Place sense lead (17) over the hole and reinstall insulator (21), washer (20) and heat sink screw (19). Tighten heat sink screw to 3 N·m (26 lb in).

NOTE: Sense lead (17) must be under insulator (21).

35. Tighten nut/lockwasher assembly on regulator stud (18) to 3 N·m (26 lb in).

36. Place rectifier cover back onto rectifier end assembly and install attaching screws. Tighten screws to 5.3 N·m (47 lb in).

37. Install end plate to rectifier end assembly and install attaching screws. Tighten screws to 3 N·m (26 lb in).

38. Check inside of rectifier end assembly for new metal shavings that may have been created by installation of self-tapping screws into the newly drilled mounting holes. Remove all traces of metal shavings.

39. Remove protective tape from the open end of bearing in rectifier end assembly. Check inner race on end of rotor shaft to be sure it is free of dirt or other foreign material. Assemble drive end assembly (with rotor) to rectifier end assembly. Install thru bolts and tighten to 6 N·m (53 lb in).

40. Place fan pulley, washer and shaft nut on shaft. Hold shaft by placing 5/16" hex drive in end recess. Tighten shaft nut to 100 N·m (75 lb ft).