Dead spot in starter?

I've had an issue on and off for years with an old Farmall 350. 90-95% of the time you hop in the seat and hit and starter button and after turning the engine over 3 times it fires up and goes. Every once in the while you hit the starter button and the solenoid clicks and thats it. You might hit the button 3-4 times and suddenly the starter kicks in and everything works like it should.

This spring the click and no start issue seemed to be getting worse so I tried a half arsed fix and replaced the starter solenoid (once in the while it would throw sparks when engaged) hoping that would fix the issue. It seemed to fix it but not totally. Saturday it did it again only no amount of coaxing would get it do more than "click". I added the battery power of my truck to the situation (800 cold cranking amps) and got a puff of white smoke out of the starter for my efforts. Wife dropped the starter off at the dealership and they called and said it works just fine. I described the situation to them and the guy said it probably has a "dead spot" where the starter just won't spin and its probably getting worse as time goes by. He said you can run it until it burns out completely or get it rebuilt - something they don't do or buy a new one (on here they are about $213).

Ever hear of a dead spot? It kind of makes sense to me but then I've never heard of it before.
 
Yes they do get dead spots. take the armature out and lay it on something that won"t conduct then get your v o m and go around it (ohms) you will find it if it has a dead spot. sometimes you can solder it at the comutator.
 
Not a ring gear issue (and I was wondering if that wasn't the issue too). I was pleasently surprised how good the gear on the starter and the ring gear looked when I pulled the starter.
 
It sounds like a dead spot on the armature and you might be able to see it if you look close on the commutator bar ends. There will be a burnt spot although I don't know that you could see any sparks on the outside of starter from that, maybe where the field post comes through the side of the starter and attaches to the solenoid.
 
Are all your electrical connections in really good shape? Sparks are a sign of a bad connection. Bad connections will not give you the required voltage all the time.
SDE
 
The dead spot can be caused by a poor solder connection or more likely worn brushes. As the brushes wear down they also cause wear on the commutator bars causing them to get out of round. If a brush has worn enough that it can no longer make good contact it will act as a dead spot.

If your starter is still an original Delco Remy unit you are better off getting it rebuilt rather than exchanging it for a new Asian model or who knows what if you get a rebuilt one.
 
What you need to do is take the starter to an automotive electrical shop, not your CaseIH dealer. Some place that rebuilds starters and alternators for a living.

But before you do that, do like others have said and clean up all your connections. Visible sparks indicate a problem external to the starter.
 
I cleaned up the connections when I replaced the solenoid. The sparks were actually originating in the old solenoid (yeah it was pretty rough looking when I got it off) - not the connections.

The plan is to have it rebuilt, the problem is finding a place that does that kind of work anymore.
 
Dan,For 200, dollars,ill bet if you bite the bullet and replace the starter for a new one youll never be sorry.Agravation is very expensive.I just put out some money on my F14 but now it works perfectly,money well spent

jimmy
 
I bit the bullet and bought a new starter a few years ago because the end cap on mine was cracked and the gear was a bit chewed up. Worked well for two or so years and then all sorts of issues. Now mind you this is not an everyday use machine. Tedded use during hay season send pulling a wagon of wood on the fall. First the brushes wore down to nothing and then intermittent dead spots. Ended up replacing all the internals with the stuff from the old starter. Now it works better than ever. This new stuff has no quality control.
 
Not close to you but I have dealt with them in the past
might give them a call.
Van's Carb & Electric in Indianapolis.
They have done 4 six volt starters for me & many 12 / 24 volt starters & alternators for the company I used to work for.

I would ask some local auto repair shops in your area, they might be able to steer you to someone who specializes in analyzing & repairing older 6 volt systems. Local car show guys are also usually a big help in offering a name for you as well.
 
It should be easy to spot a dead spot on the armature. A bar will be burnt and most likely some thrown solder in the band. I will add to the discussion that ordinarily a dead spot will not respond after several clicks of solenoid. Dead is dead until armature is turned to next bar. Most solenoid problems result from low voltage to the signal terminal from switch to the solenoid after you are sure of all your cables and connections of course, (actually it is a magnetic switch on the 350 as a solenoid is the type that also pulls the drive to engaged position). The easy way to test this is if it clicks, quit using the starter switch and jump directly from the battery cable at starter to the magnetic switch small terminal. If it engages starter you know you have no dead spot, rather you have low voltage through your switch & or wiring. A relay to magnetic switch is often the best solution to those type of problems. Far as rebuilding, where are they getting parts. Most likely China as original Delco parts are not to be had so if you need armature or fields, you are in trouble. I know this because I rebuilt a lot of starters and quality parts are almost nonexistent now days. A rummage through a bunch of old cores and pick the good parts would be the best but that is not an option for me anymore either.
 

Those older starters were simple creatures. Maybe you could try your hand at fixing it yourself. If you post a few good pictures of the commutator end of the armature and also the brushes after you have it apart a bunch of the guys on this site could give you advice. That old starter is well worth fixing and you have nothing to lose. You can't screw it up THAT bad.
 
You will need to give them a call.
Typical rebuild brushes, bearing, bushing back then was around $95. Armature or commutator replacement was up around $225 plus.
That was a decade or so ago so the price seems within reason.
 

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