Motor Testing

[yurtle]

Clean the commutators, which are where the brushes make contact, with a ScotchBrite or very fine sandpaper (emory cloth). Then check continuity on the rotor and stator terminals. Also test to make sure they don't have continuity between each other.

[Z71mtr]

OK I tore the motor apart and found that the brushes are stuck in the little retainer. I got one of them to move but I could not pull the rotor out....I am assuming it is because the end bearing is seized up in the bell of the motor. Does anybody have an idea how I can brake the brushes free from the retainer clip holding them in place? Something I can spray on it?

Everything else in the motor is in great shape. It doesn't look very dirty or have much carbon buildup. I watched a video on YouTube where a guy hooked up A1 to S1 and then A2 to S2.....he then hooked up a booster with the positive being on A2 and the negative being on A1. The motor ran.....is this the correct way to achieve a motor test?

[rib33024]

Do not hook power to the motor if it's not bolted to the rear end

[Z71mtr]

OK why?

[Z71mtr]

Sorry I read that wrong. It was bolted to the rear end when I did the test

[cgtech]

Thats how to test a "sepex"motor (only briefly). "Series" motor, connect any "S" terminal to a "A" terminal with a short cable, connect your other 2 unconnected terminals to a solid 12v source (car battery).as was noted, only while mounted to an axle.

[Z71mtr]

Again I can't get the rotor out of the housing. Can anybody tell me a trick to this?

[JohnnieB]

Attached are diagrams showing how to test Series and SepEx motors.

The motor shaft only has a bearing on one end, so if you try to run it without being attached to the differential, the armature will rub on the stators and bad thing$ will happen.

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You mentioned that you tore down the motor far enough to the brushes were stuck. Did you get the end cap off?

The armature shaft bearing is press fit into the end cap and the other end of the armature shaft has a coupler that attached to the input shaft of the differential. The splines in the coupler are probably rusted together.

If you have the end cap off, unbolt the motor housing from the differential and slide the housing off the armature. The you can get some penetrating oil on the coupler.

[Z71mtr]

I got the motor off the diff. I also took the end cap off with the rotor attached to it. So I have the end cap and the rotor stuck together. Are u saying that this is pressed in? I need to get the rotor out of the end cap so I can remove the brushes and clean the commutator.

[JohnnieB]

Originally Posted by Z71mtr

I got the motor off the diff. I also took the end cap off with the rotor attached to it. So I have the end cap and the rotor stuck together. Are u saying that this is pressed in? I need to get the rotor out of the end cap so I can remove the brushes and clean the commutator.

The bearing is pressed into the end cap, but not tightly.

Some guys have R&R'd the bearing by heating the end cap with a heat gun or hair dryer.

Getting the bearing off and on the motor shaft takes a little more oomph, but I understand it is doable without a bearing press.

I've never done either myself.