51 lincoln starter problem??

I was met with a wonderful surprise today after work when my 51 lincoln wouldn't start. I diagnosed the problem and narrowed it down to the starter motor.
I removed the motor and cleaned up the armature/commutator. then put the motor back together. now it spins but seems to have no torque.

I later read the dealer repair manual and it said "DO NOT USE EMERY CLOTH TO CLEAN THE ARM/COMM."..."Use a lathe, and #00 sandpaper"


did i screw up the arm by sanding it to clean it up?

 

Assuming that when you say "now it spins but seems to have no torque" you mean it starts but seems to to turn over slow. It could be nothing more than bad battery and starter connections.

 

Do not use emery cloth because the left overs can get caught in the micah and can conduct electricity. Common tan colored sand paper will not. The old guys would take a broken hack saw blade and grind both sides to narrow it. Use that tool to undercut and clean between each segment of the armature.

 

sounds like one of the brushes aren't hitting, or hitting lightly!! where they worn?
JimV

 

yeah, brushes were worn a lot. I took the armature to a shop to be turned and checked on a growler, and bought and installed new brushes, now the motor only seems to lock in place when i apply power. I checked that the windings weren't grounding. I am confused as to what to do next.

 

The shop wired the insides wrong if its "locking" in place when power is applied. The armature and field are wired incorrectly.

 

I am not sure what you mean when you say they wired it incorrectly. there is only one stud that connects to the field coils, then to the insulated brush holders on the brush plate. then there are two non-insulated brush holders, and those brusher are connected to the case.


as of tonight, still no start even with new brushes and a turned arm. seems to have zero torque. it will spin until it engages the flywheel, then stop. I have also checked that the motor is not locked up.

Also, I have given it 12v, and cleaned all of the connections.




thanks HAMB!

 

Ok, so the starter will motor, but not enough umph to turn the engine over, correct? Hows the charge on your battery?

 

good, I have 5.98v on the 6v batt in the car, and i have tested it with a good 12v batt as well.

 

With a 12v battery it should spin that starter plenty hard.

When you bench test the starter with a 12v battery, does it spin fast with NO wobble or irregularity in the cycle of the motor? If so then I think either the armature or fields are needing replaced.

 

i've got to go and pull it and re-test. I had it at an automotive electrical shop, and the guy told me that it didn't work on my original bench test because it didn't have the through bolts tightened against the bellhousing or some nuts. "they need to be tightened against something otherwise they won't work"...


I'll update when i can.

 

Yea, throw some nuts on the backside of the case and tighten the case bolts down. Then lock it in a vice and test it again.

 

Hi Nick, It's been awhile since You found the 51.

Listen to the Doc, I think He's got You on the road to recovery. Good Luck, Rich