0115000 JOHNSON DRIVESHAFT, Gearcase

Removal
IMPORTANT: Disconnect battery negative (-) cable at the battery.Disconnect battery wires from terminals and field wire connector.Loosen bolts attaching alternator to mounting brackets and remove drive belt.Remove attaching bolts and alternator.
Fig. 1-Delco-Remy AlternatorRepair
Fig. 2-Separate FramesRemove through bolts. Pry stator and slip ring end frame assembly from the rotor and drive end frame assembly. After disassembly, place a piece of pressure-sensitive tape over the slip ring end bearing to prevent entry of dirt or foreign material.Drive End Frame Bearing
Fig. 3-A-209 ToolRemove pulley, fan, and collar. Then separate the drive end frame from the rotor shaft. Remove the retainer plate and press bearing from the end frame (Fig. 3). The bearing may be reused if it is in satisfactory condition. Clean the bearing and fill it 1/4 full with Delco-Remy Lubricant No. 1948791 before assembly. Overfilling bearing may cause bearing to overheat.
Fig. 4-A-203 and A-207 ToolInstall bearing (Fig. 4). Install new retainer plate if felt seal is hard or excessively worn. Fill cavity between retainer plate and the bearing with 1948791 Lubricant. Install rotor, collars, fan and pulley. Tighten nut to 40 to 60 lb-ft (54 to 81 Nm) (6 to 8 kg-m) torque.Slip Ring End Bearing
Fig. 5-A-209 ToolReplace the slip ring end bearing if its grease supply is exhausted or if the bearing is defective. Do not attempt to relubricate bearing. Press bearing from outside to inside of frame (Fig. 5).
Fig. 6-Install Slip Ring End BearingTo install a new bearing, place a flat plate over the bearing and press it in from the outside towards the inside of the frame until the bearing is flush with the outside of the end frame (Fig. 6). Support the inside of the frame with a cylinder to prevent breakage of the end frame.Stator and Slip Ring End Frame
Fig. 7-Stator Ground CheckBefore removing brushes or diode trio, check for grounds between points A to C and B to C (Fig. 7) with an ohmmeter, using the lowest range scale. Then reverse the lead connections.If both A to C readings or both B to C readings are the same, the brushes may be grounded because of a defective insulating washer and sleeve at the two screws. If the screw assembly is not damaged, the regulator or diode trio is defective.Diode Trio
Fig. 8-Diode TrioTo check the diode trio, first remove the stator. Then remove the diode trio, noting the insulator positions. With an ohmmeter, check between points A (Fig. 8) and D and then reverse the ohmmeter lead connections. A good diode trio will give one high and one low reading. If both readings are the same, the diode trio is defective. Repeat this test at points B and D and at points C and D.Rectifier Bridge
Fig. 9-Rectifier BridgeThe rectifier bridge has a grounded heat sink (1, Fig. 9) and an insulated heat sink (2) that is connected to the output terminal. Connect ohmmeter to the grounded heat sink (A) and to the flat metal strip (B, Fig. 9). Then reverse the ohmmeter lead connections. If both readings are the same, the rectifier bridge is defective. Repeat this test between points A to C, A to D, B to E, C to E and D to E.The ohmmeter check of the rectifier bridge, and of the diode trio as previously covered, is a valid and accurate test. Do not replace either unit unless at least one pair of readings is the same.Brush Assembly and Regulator
Fig. 10-Rectifier BridgeCheck brushes for continuity between points A to B and C to D (Fig. 10). Wiggle the brush to locate poor connections.After removing stator and diode trio, the brush assembly and the regulator may be removed. The screws at points B and C must have insulating washers and sleeves. A ground at these points will cause no output or uncontrolled output.Rotor
Test A-Short Circuit or High Resistance
Fig. 11-Rotor Current Draw TestConnect voltmeter (1, Fig. 11), ammeter (3), and battery (4) to rotor (2).This test checks for short circuits or excessive resistance. The rotor winding current draws should be 4 to 4.5 amps at 12 volts.An ammeter reading above this specified value indicates shorted windings, a reading below the specified value indicates excessive resistance. Test B: Checking Field Coil for Opens
Fig. 12-Test B and C Test PointsTo check for opens connect the test lamp or ohmmeter to each slip ring (B, Fig. 12). If the test lamp fails to light, or if the ohmmeter reading is high (infinite), the winding is open. Test C: Checking Field Coil for GroundsConnect ohmmeter to either slip ring and to the shaft (C, Fig. 12). Test lamp should not light or ohmmeter reading should show a high resistance. If test lamp lights or ohmmeter resistance is low, the field windings are grounded.Polish slip rings with 400-grit silicon carbide paper.
Fig. 13-StatorExamine stator for insulation failure or defects. The alternator is "Y" connected (1, Fig. 13).Check for ground between any terminal and the stator frame. If the meter reading is low the windings are grounded. Check for an open circuit by connecting an ohmmeter from point A to B and from B to C (Fig. 13). If the meter readings are high the windings are open.Shorted stator leads are usually discolored and have a burned odor.Replace stator only after other electrical components have been checked and are satisfactory.Assembly
Alternator assembly is the reverse of the disassembly procedures. Be sure insulated screws for the regulator and brush holder and the insulating washer for the rectifier bridge are assembled correctly (Figs. 1 and 7).
Fig. 14-Brush Pin HoleTo connect the slip ring end frame assembly to the rotor and drive end frame assembly, insert a pin through the hole (Fig. 14) to hold the brushes up. Remove the tape over the slip ring end bearing and make sure the shaft is perfectly clean. Carefully install the shaft in the slip ring end frame assembly to avoid seal damage. After tightening through bolts, remove the brush retaining pin.Mount alternator on electrical servicer. Make connections shown in Fig. 15 using an AR55283 Delcotron