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26SI Series Alternator – Alternator

Illustration 1 g00620646

Front View of the 26-SI Alternator

Illustration 2 g00620650

Side View of the 26-SI Alternator

Illustration 3 g00620651

Rear View of the 26-SI Alternator
Table 1
Specifications for 26-SI Alternators    
Part Number
Remanufactured Part Number    		 3E-7577
OR-3615    		 3E-7578
OR-5206    		 112-5041
OR-5206    		 3E-7892
OR-3616    
Voltage Rating     24V     24V     24V     12V    
Current     75A     50A     50A     85A    
Application     Extra Heavy Duty     Extra Heavy Duty     Heavy Duty     Extra Heavy Duty    
Weight     12.5 kg (27.6 lb)     12.5 kg (27.6 lb)     12.5 kg (27.6 lb)     12.5 kg (27.6 lb)    
Polarity     Negative Case Ground     Negative Case Ground     Negative Case Ground     Negative Case Ground    
Minimum Full Load Current (Cold) at 5000 rpm     67A     47A     47A     77A    
Minimum Full Load Current (Cold) at 1500 rpm     29A (1) (2)     18A     18A     38A    
Amperes at
27 °C (80 °F)and 1800 rpm    		 45     33     33     56    
Amperes at
27 °C (80 °F) and 5000 rpm    		 75     50     50     85    
Rotation (3)     CW
CCW    		 CW
CCW    		 CW
CCW    		 CW
CCW    
( 1 ) Minimum Full Load Current (Cold) at 2000 rpm
( 2 ) The minimum speed of the alternator should be 1800 rpm at low engine idle.
( 3 ) The rotation is viewed from the pulley.

The results for a 12 volt 26-SI Alternator’s rotor field winding test at 27 °C (80 °F) are in the following list:

  • 3.0 to 4.3 Amperes

  • 2.8 to 4.0 Ohms

The results for a 24 volt 26-SI Alternator’s rotor field winding test at 27 °C (80 °F) are in the following list:

  • 2.0 to 2.8 Amperes

  • 8.5 to 12.0 Ohms

Table 2
Torque Specifications for the 26-SI Alternator    
Part Number
Remanufactured Part Number    		 3E-7577
OR-3615    		 3E-7578
OR-5206    		 112-5041
OR-5206    		 3E-7892
OR-3616    
Pulley Nut     102 ± 7 N·m (75 ± 5 lb ft)     102 ± 7 N·m (75 ± 5 lb ft)     102 ± 7 N·m (75 ± 5 lb ft)     102 ± 7 N·m (75 ± 5 lb ft)    
Cover for the Rectifier     5.3 N·m (47 lb in)     5.3 N·m (47 lb in)     5.3 N·m (47 lb in)     5.3 N·m (47 lb in)    
Cover Plate
Regulator and Mounting Plate
Heat Sink    		 3 N·m (27 lb in)     3 N·m (27 lb in)     3 N·m (27 lb in)     3 N·m (27 lb in)    
Battery Terminal     13.5 ± 1.3 N·m (119.5 ± 11.5 lb in)     13.5 ± 1.3 N·m (119.5 ± 11.5 lb in)     13.5 ± 1.3 N·m (119.5 ± 11.5 lb in)     13.5 ± 1.3 N·m (119.5 ± 11.5 lb in)    
“R” Terminal
Nut for the Regulator Stud    		 2 N·m (18 lb in)     2 N·m (18 lb in)     2 N·m (18 lb in)     2 N·m (18 lb in)    
Nut for the Hex Mounting Bolt
Bolt for the Adjusting Lug    		 88 N·m (65 lb ft)     88 N·m (65 lb ft)     88 N·m (65 lb ft)     88 N·m (65 lb ft)    
Frame Bolts     6.2 N·m (55 lb in)     6.2 N·m (55 lb in)     6.2 N·m (55 lb in)     6.2 N·m (55 lb in)    
Ground Screw     6 N·m (55 lb in)     6 N·m (55 lb in)     6 N·m (55 lb in)     6 N·m (55 lb in)    

Illustration 4 g00620877

26-SI Alternator Schematic