Alternator
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| Illustration 1 | g00668639 |
21-SI Sectional view | |
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| Illustration 2 | g00669400 |
Brush length | |
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| Illustration 3 | g00669426 |
21-SI End view | |
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| Specifications for 21-SI Alternators (1) | |||||
|---|---|---|---|---|---|
| Part Number | 9X-6796 9X-9096 |
121-4134 | 121-4135 117-1379 |
125-9597 | 107-7977 132-2156 |
| Maximum Runout of Slip Rings (1) | 0.08 mm (0.003 inch) | 0.08 mm (0.003 inch) |
0.08 mm (0.003 inch) |
0.08 mm (0.003 inch) |
0.08 mm (0.003 inch) |
| Minimum Diameter of Slip Rings (1) | 29.21 mm (1.150 inch) |
29.21 mm (1.150 inch) |
29.21 mm (1.150 inch) |
29.21 mm (1.150 inch) |
29.21 mm (1.150 inch) |
| Torque of Pulley Nut (2) | 100 ± 7 N·m (74 ± 5 lb ft) |
100 ± 7 N·m (74 ± 5 lb ft) |
100 ± 7 N·m (74 ± 5 lb ft) |
100 ± 7 N·m (74 ± 5 lb ft) |
100 ± 7 N·m (74 ± 5 lb ft) |
| Length of New Brush (3) | 21.9 mm (0.862 inch) |
21.9 mm (0.862 inch) |
21.9 mm (0.862 inch) |
21.9 mm (0.862 inch) |
21.9 mm (0.862 inch) |
| Minimum Length of Brush (3) | 7.6 mm (0.30 inch) |
7.6 mm (0.30 inch) |
7.6 mm (0.30 inch) |
7.6 mm (0.30 inch) |
7.6 mm (0.30 inch) |
| Torque of Four Through Bolts (4) | 5.1 ± 0.6 N·m (45 ± 5 lb in) |
5.1 ± 0.6 N·m (45 ± 5 lb in) |
5.1 ± 0.6 N·m (45 ± 5 lb in) |
5.1 ± 0.6 N·m (45 ± 5 lb in) |
5.1 ± 0.6 N·m (45 ± 5 lb in) |
| Torque of Battery Terminal (5) | 11.3 ± 2.3 N·m (100 ± 20 lb in) |
11.3 ± 2.3 N·m (100 ± 20 lb in) |
11.3 ± 2.3 N·m (100 ± 20 lb in) |
11.3 ± 2.3 N·m (100 ± 20 lb in) |
7.1 ± 0.9 N·m (63 ± 8 lb in) |
| Torque of Ground Terminal (6) | 6.2 ± 0.6 N·m (54 ± 5 lb in) |
6.2 ± 0.6 N·m (54 ± 5 lb in) |
6.2 ± 0.6 N·m (54 ± 5 lb in) |
6.2 ± 0.6 N·m (54 ± 5 lb in) |
6.2 ± 0.6 N·m (54 ± 5 lb in) |
| Voltage Rating | 12 V | 12 V | 12 V | 12 V | 24 V |
| Polarity | Negative Ground | Negative Ground | Negative Ground | Negative Ground | Negative Ground |
| Rotation | CW or CCW | CW or CCW | CW | CW | CW or CCW |
| Test Speed | 5000 rpm | 5000 rpm | 5000 rpm | 5000 rpm | 5000 rpm |
| Rated Output Current (Cold) | 111 A | 110 A | 124 A | 138 A | 70 A |
| Output Voltage | 14 ± 0.5 V | 14 ± 0.5 V | 14 ± 0.5 V | 14 ± 0.5 V | 28 ± 1.0 V |
| Resistance of Rotor Field Winding at 27 °C (81 °F) |
1.7 to 1.8 ê | 1.7 to 1.8 ê | 1.7 to 1.8 ê | 1.7 to 1.8 ê | 9.5 to 10.7 ê |
| Field Current at output voltage and 27 °C (81 °F) |
6.7 to 7.1 A | 6.7 to 7.1 A | 6.7 to 7.1 A | 6.7 to 7.1 A | 2.2 to 2.5 A |
| Resistance of Stator Winding | 0.063 ê | 0.063 ê | 0.063 ê | 0.063 ê | 0.063 ê |
| Turn On Speed (Maximum) | 2000 rpm | 2000 rpm | 2000 rpm | 2100 rpm | 2000 rpm |
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| ( 1 ) | Refer to illustration 1, illustration 2, and illustration 3. |
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| Belt Tension Chart | |||||||||||
| Size of Belt | Width of Belt | Gauge Reading | Borroughs Gauge Numbers | ||||||||
| Belt Tension "Initial" (1) |
Belt Tension "Used" (2) |
Old Gauge Number | New Gauge Number | ||||||||
| 3/8 | 10.72 mm (0.422 Inch) |
445 ± 22 N (100 ± 5 lb) |
400 ± 22 N (90 ± 5 lb) |
BT-33-95 | BT-33-97 | ||||||
| 1/2 | 13.89 mm (0.547 Inch) |
534 ± 22 N (120 ± 5 lb) |
400 ± 44 N (90 ± 10 lb) |
BT-33-95 | BT-33-97 | ||||||
| 5V | 15.88 mm (0.626 Inch) |
534 ± 22 N (120 ± 5 lb) |
400 ± 44 N (90 ± 10 lb) |
BT-33-72 | BT-33-72C | ||||||
| 11/16 | 17.48 mm (0.688 Inch) |
534 ± 22 N (120 ± 5 lb) |
400 ± 44 N (90 ± 10 lb) |
BT-33-72 | BT-33-72C | ||||||
| 3/4 | 19.05 mm (0.750 Inch) |
534 ± 22 N (120 ± 5 lb) |
400 ± 44 N (90 ± 10 lb) |
BT-33-72 | BT-33-72C | ||||||
| 15/16 | 23.83 mm (0.983 Inch) |
534 ± 22 N (120 ± 5 lb) |
400 ± 44 N (90 ± 10 lb) |
BT-33-72 | BT-33-77 | ||||||
| 8K | 27.92 mm (1.099 Inch) |
800 ± 22 N (180 ± 5 lb) |
489 ± 44 N (110 ± 10 lb) |
------ | BT-33-109 | ||||||
| 6PK | 20.94 mm (0.824 Inch) |
667 ± 22 N (150 ± 5 lb) |
467 ± 44 N (105 ± 10 lb) |
------ | BT-33-109 | ||||||
| Measure the tension of the belt that is farthest from the engine. | |||||||||||
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| ( 1 ) | Belt Tension "Initial" is for a new belt. |
| ( 2 ) | Belt Tension "Used" is for a belt that has been operated over 30 minutes at the rated speed. |
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