FORD FLATHEAD 6 Volt STARTER MOTOR REBUILD

By David O’Neill

This repair article is intended to freshen up old flathead starter motors.

For a more comprehensive break down of diagnostic testing repair refer to the factory Ford service manual or the Motors manual.

NOTES:

1. Do not run a DC series motor(starter) without a load. It can damage it.

2. Do not undercut the mica on the commutator like on generators.

3. Field resistance is low, current is high, 65 amps, torque is high.

4. With brushes out there should be no continuity from batt. post to ground.

 

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 COMPLETE 6V FORD
STARTER MOTOR

 

STEP 1) REMOVE SCREW (ARROW) THAT HOLDS THE BRUSH COVER ON. INSPECT THE BRUSHES AND COMMUTATOR FOR WEAR.

 

REMOVE NUTS AND BOLTS THAT HOLD CASE TOGETHER. NUTS KEEP IT TOGETHER WHILE WORKING ON IT.

 

REMOVE BRUSHES FROM END PLATE BY LIFTING UP ON SPRING END

 

HOMEBREW PULLER

 

 

IF THE END PLATE BUSHING
IS BAD YOU CAN DREMIL IT THIN AND USE A PULLER TO REMOVE. I MADE ONE OUT OF PIPE AND A SOCKET.

 

WHEN PRESSING NEW BUSHING IN
USE WD40 AND IT WILL SLIDE RIGHT IN

 

 

STEP 6) INSPECT THE COMMUTATOR. IF ITS SMOOTH. CLEAN IT ELECTRICAL CLEANER AND LEAVE IT ALONE. IF SCORED YOU WILL NEED TO USE A COMMUTATOR LATHE. SEE BELOW.

 

I BOUGHT THIS LATHE ON EBAY FOR $20. IT TURNS THE COMMUTATOR AND UNDERCUTS THE MICA (INSULATORS THAT GO BETWEEN THE COPPER PLATES)

NOTE*** IF YOU GET ONE OF THESE LATHES DON'T UNDERCUT THE MICA ON A STARTER MOTOR-ONLY FAST SPINNING COMMUTATORS LIKE GENERATORS.

REASON BEING IS THAT THE BRUSH DUST COLLECTS BETWEEN THE POLES AND COULD SHORT OUT THE COMMUTATOR BECAUSE THE STARTER SPINS SLOW AND CAN'T EJECT THE DEBRIS. 

 

 

AFTER INSTALLING THE ARMATURE AND END PLATE - INSTALL THE NEW BRUSHES. TWO ARE SCREWED TO THE CASE AND TWO ARE CRIMPED AND SOLDERED. USE 300+WATT SOLDERING GUN TO UNSOLDER.

 

REMOVE THE TWO SCREWS THAT HOLDS THE BENDIX ON.

 

COMPLETELY CLEAN THE GREASE AND DIRT OFF OF THIS MECHANISM.

 

CLEAN THE FRONT SHAFT ALSO.

 

PRESS IN NEW FRONT BEARING IF NEEDED.

ASSEMBLE THE FRONT PLATE AND CASE BOLTS. FRONT AND BACK PLATES SHOULD HAVE A LOCKING DETENT THAT FITS INTO THE CASE. INSTALL THE BENDIX AND SPRING AND YOU ARE READY TO GO.

 

IF YOU WISH TO BE BRAVE AND REPLACE THE FIELD COILS THE FOLLOWING INSTRUCTIONS SHOW YOU HOW TO DO IT. YOU MUST HAVE AT LEAST A 300WATT SOLDERING GUN TO WORK ON THE FIELD COILS. THE PICTURE ABOVE SHOWS HOW TO REMOVE THE FIELD SHOE SCREWS.

 

 

THE FIELD COILS WERE PURCHASED FROM MACS AUTOPARTS FOR $39 2011 PRICES. TRIM THE COPPER CONNECTORS AND MAKE SURE THEY FIT INTO THE BATTERY CABLE STUD. THE TWIST IN THE COPPER CONNECTOR IS FOR CLEARANCE FOR THE CASE BOLT.

 

CHECK ALL POINTS OF THE
FIELD COIL WITH A METER AND
MAKE SURE THERE IS NO
CONTINUITY TO THE CASE. REASSEMBLE THE STARTER.

 

300 WATT WELLER
SOLDERING GUN
       

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