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Is it possible to have a starter motor that binds under load?
My starter motor and I have certainly had our issues in the past. This problem started with some grinding noise as it started. So pulled the starter and seemed to work perfectly on the bench. Put in a shim and started with out a problem for 2 weeks. Now has a grinding (irrespective of shims) and the engine will not turn over. Looking at it underneath the drive gear engages onto the flywheel but won't turn. No the engine is not seized and the stater still works on the bench
If the solenoid is going away, the motor won't get enough current to work properly. Same if you have a bad ground (earth-I see you're in Perth). Some of the solenoids can be opened up and the positive post rotated, and the contactor disc cleaned up. Or just replace the solenoid.
That was another saga. While getting starter out the bakerlyte top on the solenoid fell apart. It was only $30 more to buy the whole solenoid than to just buy top so have a new solenoid. had bad earth problems about a year ago so that is well and truly fixed
Keep in mind that GM did install a support bracket that holds the end of your armature housing. It keeps the starter from moving or tweaking when it is put under power.
IF your armature housing is moving when the starter is being used...and you do not ahve the support brace...then you can have a problem.
ok have pulled the solenoid apart and it is working. To get round bad earth problem, disconnected battery, connected fully charged battery to the starter motor. drive gear engaged turned flywheel slightly then stopped. So there was a support bracket. No indication there has been one on mine anyone have a picture of this? well I guess it's pull apart starter motor time as I have nothing to loose!!
On your starter...at the end of the armature housing. The cover is held in with 2 bolts...and one of those bolts has a threaded stud made onto it. THAT is where the brace will attach...and then there is a threaded hole in the engine block where the brace gets bolted to the block.
Thanks for everyone's help. The ground wasn't as good as it should have been, so have rectified that. Like the idea of the bracket and I'm going to make something up just for good measure. Have started pulling apart with the aid of this video
While you have the starter apart, change the motor brushes, if the car has significant miles on it. You can find them at some of the better car parts stores or order them over the internet. Pretty easy change and puts starter back in like-new condition.
I used to rebuild these starters when I was only 20 years old, very simple to do and did not cost a lot to do. Mostly cleaning up things, you can take apart the solenoid and clean it up, takes just a few minutes to do and makes a big difference.
that film is not for the starter that the corvette uses.
Last edited by lvmyvt76; Jan 24, 2018 at 06:35 PM.
Finally I have had success!! As has been suggested, pulling the starter motor apart wasn't a problem and the video was a little over kill. Anyway, there was a lot of wear on the commutator where the brushes contact it. The lines between the commutator bars were visible but even running my nails over it, they couldn't be felt.
I don't have a lathe, so drilled a hole in piece of wood for one end of shaft and attached a drill to the other end. Now using a file I was able to remove the ridge along the inner edge of the commutator and smooth the rest of the commutator. I scratched out the gap between the commutator bars and reassembled.
Unfortunately, it was still the same in the beast of a car. I am getting quick and efficient at getting the stater motor in and out of the car. So pulled apart again, video said the depth between the commutator bars should be 1mm. Mine was barely below the surface, so broke a fine hacksaw blade and took them down to 1mm.
Reinstalled and she starts wonderfully. I realize this is wear, but hopefully I won't have to buy a new starter for a while yet.
and taking a very good look at the the bushing at both ends of where the armature fits into the end cover and the front snout.
IF these bushings are worn...it will cause the armature not to spin true...and if it is bad enough....it can cause problems due to the armature...when turning...can actually hit the field coils in the armature case. And this action can really be magnified when the bendix engages into the flywheel teeth and now the armature is pushing against it and can move and wear more and more.
So...sometimes bench testing one does not confirm that it is really good to go.
starter motor binding ?
and taking a very good look at the the bushing at both ends of where the armature fits into the end cover and the front snout.