Can a starter motor get "weak"?

Well because of work and other pressing obligations I put off changing the starter, but when I got stranded at Home Depot today I wasted no time after getting a jump to pass by O'Reilly's on the way home and pick up a rebuilt, while I left the engine running and sure enough, the starter was the problem. The guy from AAA told me the battery was fully charged and it barely cranked enough to start with his battery pack hooked up. I knew all the connections were clean, so by this time there was little doubt, actually, none.

Well, anyway after wrestling the old one out and installing the rebuilt I put all the tools away, cleaned the grime off my hands and went out to savor the joy of a fast cranking, quick starting engine. Bingo! it started right up! Only problem was the starter kept cranking. I turned the engine off but the starter kept cranking! SH#T!!! I popped the hood and tried to yank off a battery cable, but I had cinched them both down tight. I ran inside to get the 1/2 inch wrench to loose the bolt on the cable. By this time it's dark and I didn't bring out the flashlight, so I'm fumbling around doing this by feel. Finally got it loose and pulled the cable off the post and the starter stopped spinning. whew!

So I put the cable back on the post, not knowing what to expect, but nothing happened. I leave the hood up and the cable loose on the post and go to try again, being ready to sprint back to the battery to pull the cable if necessary, but this time the starter motor disengaged. I tried it several more times with no drama. The engine started and the starter disengaged every time. Cool, but not cool. I disconnect the battery cable so as not to have to worry about the starter spontaneously starting.

I go to Google and look up 'starter motor keeps cranking' and found this not to be an entirely uncommon problem. The possible cause that appealed to me the most was that a new or rebuilt starter has tolerances that are tight, causing the solenoid not to disengage. This problem, I was lead to believe, can work itself out as the starter does its work . I thought maybe the minute and half that this one was cranking while I fumbled to pull the battery cable might have done just that. I'm hoping that's the case because that would mean no more work. But it seems just as likely from the symptoms that the starter relay was stuck. But this has never happened before, so I'm leaning toward the rebuilt starter as the source of the problem. But tomorrow I will pull the relay and pop it open to inspect the contacts for any sign of weld spots.

I'm assuming that the starter was cranking the engine after I turned the key off and not just spinning. The fact that it continued for so long cranking at a good solid rpm tells me I should have no starting problems for quite a while. But I am going to disconnect the battery at night until I feel comfortable that it won't spontaneously start :-)

I also see that this thread seemed to take on a life of its own after my last post. I have some catch-up reading to do!

Jack

Reply to
Jack
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You remember earlier when people were warning you about crappy chain store rebuilds? This is why.

--scott

Reply to
Scott Dorsey

I'm not familiar with an '87 Dakota in particular, does it have a solenoid mounted on the starter, or is the solenoid remote and the pinion engagement governed by a centrifugal style "Bendix" mechanism?

nate

Reply to
Nate Nagel

I knew that at least one incompetent clown would make that spurious claim wholly irrespective of ANY issue whatsoever that you might experience in the lifetime of the vehicle.

But had he a clue, he would have first informed you to check a couple of items first before indicting the starter as the issue, not that there is any better a guarantee that a more expensive unit (be it new or rebuilt) would undoubtedly be free of any problem.

Verify that there isn't an issue with either the start circuit being continuously energized, and also that the starter drive isn't binding and unable to disengage with the ring gear indicating that shims may be required. In any case, if the motor achieved speeds above idle (for whatever reason), I'd seriously consider returning the starter for warranty replacement as armature winding can begin to bloom (expand) when driven at too high an rpm.

Reply to
Gene

One other thing, when possible (and feasible), so as to save myself some unnecessary labor, I always bench test (and of course verify exact replacement of) an item before installing.

Reply to
Gene

Solenoid is integral and directly engages the pinion gear. I just finished removing the starter relay for inspection. It looked as if it might have experience a spot welding episode, although what I saw may have just been the result of normal operation. In any case I buffed the contacts with wet/dry sandpaper, reinstalled it and gave the engine a couple of starts with no problem. I will assume that this was a one time event unless and until it happens again. In the meantime I am leaving one battery cable loose.

Reply to
Jack

The fact that this has never happened before in the 26 years I have owned this truck, and that it happened on the first start with a new rebuilt starter points strongly to either the starter or the installation. This is the 3th or 4th starter I have installed since this truck was new in about 130,000 miles. I don't know what the average lifespan of a starter is on this truck, whether this is par or not, but I have always just swapped out the old for the new with no problem until now.

I don't know if this new rebuilt starter is turning the engine faster than idle, but it sure as heck is turning it faster than than the old one, and that is what I was looking for. So far it seems to be a one time problem, as the engine has started up normally several times after this episode, but I'm leaving the battery cable loose just in case.

Jack

Reply to
Jack

You can be sure I will keep that in mind if the need to change the starter ever comes up again :-)

Reply to
Jack

I must not have been clear. What I meant was that after the engine, started, if the engine was reved much above idle, starters don't like that and the armature windings can, given a high enough speed and long enough period of time, expand radially and then bind with internals such as the field coils.

Reply to
Gene

Ah... I see. Well, only time will tell, but so far so good. The engine is starting up fine at present. I didn't rev the engine when this event happened, but the carb was on fast idle. The starter seems to have survived. It's the lifetime warranty Ultima starter from O'Reilly's, so if it goes south I'll just get another.

Jack

Reply to
Jack

Hard to say whether it's an electrical or mechanical issue... just keep an eye on it.

Had the same thing happen on a starter on my '55 Stude (don't remember what starter though, it was a 12V starter I know that because I'd converted it, forget if Delco or Prestolite) problem ended up being a bad ignition switch! sounded like a turbo screaming but it was the starter staying engaged...

Not applicable to your situation but when bench testing starters with a "Bendix" drive (actually a misnomer - I'm referring to the later "Folo-Thru" design but still commonly called a Bendix by mechanics because it looks identical) the gear will not retract after it kicks out

- it needs the overrun of being driven by an engine that's started to kick it back in. So there really is no good way to test one of those

100% without a running engine...

nate

Reply to
Nate Nagel

After reading up on this starter in the shop manual for the truck, I find it is a "reduction gear overrunning clutch type with a solenoid mounted on starter motor". The overrunning clutch would prevent the flywheel of a running engine from turning the armature windings at a higher speed than than they turn under normal starting operation if the pinion gear fails to disengage, so there should be no danger of the armature windings expanding radially and then binding with internals.

Jack

Reply to
Jack

For what it's worth, the shop manual describes the starter thusly, "Starter motor drive is a reduction gear overrunning clutch type with a solenoid mounted on starter motor." Isn't this a different design than a Folo-Thru drive and therefore could be successfully bench tested for the failure to disengage condition?

Jack

Reply to
Jack

Absolutely. The type you have should retract as soon as the "control" voltage is removed from the solenoid.

nate

Reply to
Nate Nagel

Ah, right... you DID post that the info on the Folo-Thru was not applicable to my situation. That didn't register the first time I read it.

Reply to
Jack

Yes, that will not occur in a normally functioning starter, but it can and does happen. If you don't believe me, ask any experienced mechanic whether they've ever seen a "blossomed" armature. If they respond that they haven't, they're either insufficiently experienced, or a prevaricator.

Reply to
Gene

I don't think that's what was meant, he's referring to the nature of the one way, sprag clutch, not the spring which, via linkage, pulls the starter out of mesh when the solenoid is de-energized in that specific application.

Reply to
Gene

But I am not dealing with a "normally functioning starter". I am dealing with one that failed to disengage the first time was used. The point I am trying to nail down is that this "blossomed armature" problem should not occur in an overrunning clutch type starter, which is what I have, if it fails to disengage, for whatever reason, and the overrunning clutch functions as it should. Am I right or wrong on this, in your opinion? Since you warned me that "if the motor achieved speeds above idle (for whatever reason), I'd seriously consider returning the starter for warranty replacement as armature winding can begin to bloom (expand) when driven at too high an rpm," I need to know this so I can calibrate the amount of time I spend worrying about it.

Jack

Reply to
Jack

I wouldn't worry about it if you don't notice a slowly running, or any noise from a, dragging starter A fast idle alone, particularly for a non-extended period of time, is very unlikely to precipitate this issue.

Reply to
Gene

It sounds like, from reading the thread, you already purchased a "lifetime warranty" starter, and that changing the starter on this particular vehicle is not that terribly onerous a task. If both of those are the case I probably would just ensure that I kept the receipt for your current starter and stop worrying about it unless you continue to have issues with it. Personally I prefer to know that everything is perfect, but at some point you just have to accept that it's working and move on.

nate

Reply to
Nate Nagel

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