carmover

25 Buick first start issues

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1 hour ago, Hubert_25-25 said:

Ron, 

       I think the first order is to determine why this broke in the first place.  Possibly the SG unit was not motoring or there was no battery and someone was determined to push down on the starter pedal and it can't handle that if it is not engaged and can mesh thru the gear teeth?   If the rod is lubricated and slides freely, I would guess that is what happened to it.

Repairing castings is always my last resort.  They are hard to fix properly.  First choice would be to either find another one of these forks or to have a new part fabricated from good steel.    Hugh

Hugh, This fork is not my problem as this is a good fix and has been working fine for years.The brush is real close to the commutator so close that it is trying to turn the motor and is sparking.All I have to do is touch it with the wooden rod and the starter comes alive and turns the motor.The shaft is all the way up to the bell housing like it should be I just need a touch more pressure on the brush.

Edited by carmover (see edit history)

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Ron, 

    It sounds like the starter brush is not rotating freely on the shaft.  You can remove the front cover and pull the small cotter pin and spring on the end of the support shaft.  This will allow you to remove the Upper Motor brush and clean and lubricate the pivot point.  Note that the Upper Motor Brush arm spring behind the arm is pushing on a stud, and that stud has an insulator on it, and the insulators are fragile.  Probably now a plastic material but used to be Micarta.    

 Hugh

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40 minutes ago, Hubert_25-25 said:

Ron, 

    It sounds like the starter brush is not rotating freely on the shaft.  You can remove the front cover and pull the small cotter pin and spring on the end of the support shaft.  This will allow you to remove the Upper Motor brush and clean and lubricate the pivot point.  Note that the Upper Motor Brush arm spring behind the arm is pushing on a stud, and that stud has an insulator on it, and the insulators are fragile.  Probably now a plastic material but used to be Micarta.    

 Hugh

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Hugh, The only thing is it works perfectly on the bench, you can even hear it hit the commutator.But when on the car with the tapered shaft it is not making full contact.

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Ron, 

    One other thing that could be causing insufficient spring pressure on the Upper Starter brush is the linkage and spring from the upper generator brush.  I would have to think thru all this, but conceptually it is perhaps more likely that the adjustment on the upper brush is preventing the starter brush from making good contact.   Instead of pushing a wood stick on the starter brush, lift up on the generator brush linkage and try engaging the starter.  Or put paper between the starter commutator and the brush and feel how much drag there is when you pull on it.  Then do the same with the arm lifted to see if it is exerting more pressure on the paper.  

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It may also be a weak spring and/or a brush that is not arced to match the commutator.

 

Get a marker or pencil and cover the face of the brush, then spin the shaft a few times and look at the wear pattern on the brush.

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It looks to me also that the only time the starter brushes are engaged is if the tapered shaft is fully away from the insulating roller.  Perhaps your tapered shaft is not going all the way out and away from the roller.  Maybe that is why it works on the bench and not in the car.  Could the repair to the starter fork be preventing the pointer from moving all the way.

Edited by Hubert_25-25 (see edit history)
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On ‎3‎/‎21‎/‎2018 at 10:33 AM, carmover said:

Well I have found the problem,as it has been suggested I took a wooden dowel and pushed down on the start brush and starter came to life and turned the motor.Now that I know what it is I will try to fix it and let everyone know how it comes out today.

 

How about that. ;) :D

 

Happy for you!

Edited by JerryVan (see edit history)
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1 hour ago, Hubert_25-25 said:

It looks to me also that the only time the starter brushes are engaged is if the tapered shaft is fully away from the insulating roller.  Perhaps your tapered shaft is not going all the way out and away from the roller.  Maybe that is why it works on the bench and not in the car.  Could the repair to the starter fork be preventing the pointer from moving all the way.

Hugh, The strange thing about this whole deal is the shaft is as far back to the bell housing as it can go .I can't see if the roller is touching it or not but looking the best I can it appears that the roller is about half way down the tapered part of the shaft. I don't believe that the fork repair has anything to do with it as it only took up some play at the starter pedal.

Edited by carmover (see edit history)

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If it was a complete rebuild, maybe it's a newer, fatter roller?  Or maybe there's something in the linkage that keeps the shaft from fully retracting.  Is the linkage adjustable?

 

Did you get all the old parts back that were replaced in the rebuild?

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28 minutes ago, KongaMan said:

If it was a complete rebuild, maybe it's a newer, fatter roller?  Or maybe there's something in the linkage that keeps the shaft from fully retracting.  Is the linkage adjustable?

 

Did you get all the old parts back that were replaced in the rebuild?

I checked my records and the rebuilt start/gen was delivered to me April 2017 this whole starter is brand new and the roller is perfect and as I have said many time is it was working perfectly before the rebuild of the engine.Since the brush makes perfect contact to the commutator the shaft is what has to be causing this.I don't think that I got all of the old parts back and I do know the my old roller was worn out.I can't blame the starter itself because it operates like it should off the car and only when the shaft is in there does it cause trouble.

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I now have it working properly although I haven't installed the starter pedal yet.I carefully dressed down and polished the taper on the shaft and it is lifting and dropping the brush as it should.I will keep everyone informed on the results.:)

Edited by carmover (see edit history)
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I am a happy man problem is perfectly solved now!When I step on the starter pedal the starter comes to life and turns the motor perfectly.I did not expect this thread to reach 10 pages but with all of you standing with me and coming up with more and more ideas and helping me solve this mystery, I appreciate it more than words can express.I hope one day I can come to the Nationals and meet you guys face to face!:D

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