John Deere M starter

[hrbburn]

I have an MT that the starter has quick working. It has been fine till yesterday. It has 12v to the lug but when I pull the lever it does nothing. I tried taking the battery hot wire and touching to the copper starter stake "with the switch taken off". The first time I did this it did spark when I touched the wire, now I don't get any sparks or anything and it doesn't try to start at all. I can pull start the tractor just fine. Does anyone have a parts blow up, or a starter repair guide that would help me take this apart and troubleshoot or repair? Any help would be greatly appreciated. Thank you.

 

[jCarroll]

For not much money, and not much work, replace the switch on top of the starter.
It's a common aftermarket switch, don't have to get Mother Deeres switch.

 

[Randy G]

Remove the starter and put it in a vise...TIGHTLY!!. Remove the rear dust band and examine the 4 brushes. May be bad. Hook to a battery. Touch the positive red cable to the contact stud under the button switch and touch the black ground cable to a bare metal spot on the starter. Should spin. While its spinning see if there is alot of sparking under the brushes. There shouldn't be. They are a rather simple thing to work on. Armature may also be bad. If you take apart be sure to mark where the nose, main body and rear brush plate line up together.

 

[Jo Bird]

For a parts diagram /parts list go to the free online JD parts book, search for "M", catalog 848 pg 127/128.

 

[Randy G]

Remove the starter and put it in a vise...TIGHTLY!!. Remove the rear dust band and examine the 4 brushes. May be bad. Hook to a battery. Touch the positive red cable to the contact stud under the button switch and touch the black ground cable to a bare metal spot on the starter. Should spin. While its spinning see if there is alot of sparking under the brushes. There shouldn't be. They are a rather simple thing to work on. Armature may also be bad. If you take apart be sure to mark where the nose, main body and rear brush plate line up together.

 

[James Howell]

Presuming the battery is good, check the ground cable first for a good, clean connection on both ends of the cable/strap.

Check the other battery cable to the staring motor on both ends for a good, clean connection.

Using a test light, check for power at the starter switch.

If there is power to the starter switch, then remove the starter switch.

Take a look at the diagram below.

Note the terminal stud (Key 38).

<font color="#ff0000">[b:654c4848f0][i:654c4848f0]CAUTION: MAKE SURE THE TRACTOR IS OUT OF GEAR.

MAKE SURE THE IGNITION SWITCH IS TURNED OFF.[/i:654c4848f0][/b:654c4848f0]</font>

With the tractor out of gear and the ignition switch turned [b:654c4848f0]OFF[/b:654c4848f0], touch the batter cable to the terminal stud on the starting motor.

If the starting motor turns over, then the starter switch may not be making contact with the terminal stud.

Either the contact terminal on the starter switch may be worn out or the terminal stud on the starting motor may be worn out.

If the starting motor does not turn over, then remove the starting motor and have it tested and/or repaired.

We have replaced several terminal studs on starting motors on our tractors.

It could also have a faulty starter drive.

We have also replaced starter drives on a couple of our tractors.

Hope this helps.

 

[hrbburn]

Gentlemen, Thank you for the help. Randy, I had done as you mentioned, touching the positive cable to the stud, it did nothing. The odd part, is the first time I touched it, sparks flew, which I would expect. But after that I touched it several more times but got no sparks at all. I did clean up the battery terminals including the ground to the tractor. Any explanations for why I don't see any sparks when touching the battery cable to the contact stud?

 

[jd2cylman]

If touching the battery cable directly to the starter stud doesn't do anything, the starter obviously has an open somewhere. Pull it off and let your favorite rebuilder have a whack at it.
That's what I'd do.

Adrian

 

[Randy G]

It may not be sparking because it has no good ground to complete the circuit. Did you check the brushes? You may also have a open circuit inside the starter. Take the rear dust cover off and check continuity between the contact stud and the brushes. 2 should show continuity and 2 should not. If none show, then the starter needs worked on.

 

[Dave H]

I had that deal on a 420, it was the switch like JCarroll referenced.

 

[hrbburn]

Can you give me some help with how the starter comes off. It doesn't look to be bolted on so what is holding

 

[jd2cylman]

There's a setscrew and jam nut on the right side that is into the nosecone of the starter. Loosen the jam nut, back out the setscrew and pull out the starter.

Adrian

 

[hrbburn]

Adrian, Thank you, I thought maybe that was it but didn't want to tear something up if I was wrong. This sight is great with all the people like yourself willing to help out. Since you seem to be familiar with the MT's I will also let you know, I am looking for a set of rear wheels. This tractor was given to my son by his grandpa and he is having a blast with it but also trying to fix it up. The rear wheels are completely rusted out. If you know of a good deal, let me know. I see the going price is around $200 but that is out of his budget.

 

[jd2cylman]

Not to be too modest, but I've only seen a few M's. BUT, they're a lot like my 320 &amp; 420.
What size rims and where are you located? I have a take off set of rims from my 430W. They are 12"x28" with 9 bolt centers for 13.6x28 tires. I don't have any tires though, just the rims. I'm near DeKalb, IL.

Adrian