New Starter Shredded

[Mentone22]

This starter on my Massey Ferguson 50 has only been on the tractor since September.
It was a fairly cheap starter but seemed to be working fine until today when it wouldn't do anything.
Upon taking the starter apart it was obvious why. The entire insides were pretty much shredded.

The only thing I can figure is maybe the gear got stuck against the flywheel the last time I ran it and it was spinning the starter the whole time I was mowing.

Funny thing is the gears look fine.

Has anybody had this happen or know why?

 

[Bob Bancroft]

This starter on my Massey Ferguson 50 has only been on the tractor since September.
It was a fairly cheap starter but seemed to be working fine until today when it wouldn't do anything.
Upon taking the starter apart it was obvious why. The entire insides were pretty much shredded.

The only thing I can figure is maybe the gear got stuck against the flywheel the last time I ran it and it was spinning the starter the whole time I was mowing.

Funny thing is the gears look fine.

Has anybody had this happen or know why?
View attachment 135110

Did the screw come out of one of the positive brushes, or did the brush break? I can't for sure see what all is missing, but if a brush was flailing around in there I suppose it could cause damage.

 

[GChief]

but if a brush was flailing around in there I suppose it could cause damage.

I'm thinking it would probably be beat into carbon dust before it did that kind of damage, but could be wrong

Can't tell much from the pics, looks like a bunch of carbon dust in the bottom of the first pic.

Just noticed the blurry stuff at 1100.

 

[Mentone22]

Did the screw come out of one of the positive brushes, or did the brush break? I can't for sure see what all is missing, but if a brush was flailing around in there I suppose it could cause damage.

It was so chewed up in there that I really can't tell. Then again I'm no expert and would have to have a new one to look at to try to put the puzzle together.
Whatever that part to the right is called is supposed to have those 1/8" copper wires around the top and bottom but that section at the bottom are all stripped off.
The electric wire you can see is chewed all up
I don't know where the screw lying on the bench came from but it was loose in there.

 

[GChief]

Need better resolution and in focus pics.

Edit: If I had it in my hands (I wish for my job) I could probably tell you. Below is one of motors (MGT) I often refurbish and do failure analysis on. Pic from a Google search.

 

[Mentone22]

I'm thinking it would probably be beat into carbon dust before it did that kind of damage, but could be wrong

Can't tell much from the pics, looks like a bunch of carbon dust in the bottom of the first pic.

Just noticed the blurry stuff at 1100.

Yeah it was pretty much full of carbon looking dust and pieces of copper wire and wire insulation off of that other wire that is ripped in half,
Plus that screw and unrecognizable stuff.

I ordered another starter but if possible I would like to find the cause so it doesn't happen again. Gears sticking in the flywheel is the only thing that makes sense to me, but I would have figured the gear would be messed up too.

 

[joeysmith]

Well a wood screw normally shouldn't be in a starter
Probably been in there loose chewing things up since you got it
Finally did enough damage it wouldn't work

 

[Mentone22]

Well a wood screw normally shouldn't be in a starter
Probably been in there loose chewing things up since you got it
Finally did enough damage it wouldn't work

I was surprised to see a screw that looked like that in there but I never took a starter apart before.
I've replaced some starters over the years but never rebuilt one.

 

[rustred]

first time i have seen what looks like a sheet metal screw in a starter. so i would presume the screw came loose and the brush must have turned then fell apart . where is the other brush ? like to see that. looks like your right it is a cheap starter.

 

[rustred]

Yeah it was pretty much full of carbon looking dust and pieces of copper wire and wire insulation off of that other wire that is ripped in half,
Plus that screw and unrecognizable stuff.

I ordered another starter but if possible I would like to find the cause so it doesn't happen again. Gears sticking in the flywheel is the only thing that makes sense to me, but I would have figured the gear would be messed up too.

if the drive stayed engaged it would have thrown the armature windings off.

 

[used red MN]

Did the screw come out of one of the positive brushes, or did the brush break?

Unfortunately for you I would say Bob has you answer. My guess is the “wood screw” is a self threading screw that threads itself into the plastic positive brush holder but didn’t hold sufficiently or cracked/broke it. Very likely a “land of almost right” shortcut assembly process. That’s what I’m seeing. Someone with a little experience, with the proper replacement parts and the ability to solder could probably resurrect it.

 

[Bob Bancroft]

Well a wood screw normally shouldn't be in a starter
Probably been in there loose chewing things up since you got it
Finally did enough damage it wouldn't work

I can't remember what type of screw holds the live brush to the plastic. I don't remember if it is a machine screw or a type of self tapper. I should know because I've had plenty of them apart. But it's been 40 plus years, so I don't know. Regardless, it wouldn't be all that difficult to strip out the plastic, or force the wrong screw in there, spread and crack the plastic. It's a machine screw which holds the ground brush to the metal holder. It goes through a thin enough piece that I suppose it wouldn't be all that difficult to mess that up too.

 

[Mentone22]

I found a matching screw like the one that was loose. I holds a copper lug where the insulated wire attaches.
I don't know for sure it it coming loose was a cause or effect of damage.
You can also see the pin that holds that arm is badly bent.

 

[Mentone22]

This is where those swirling copper wires were ripped off and shredded up.

 

[MM-TX]

I found a matching screw like the one that was loose. I holds a copper lug where the insulated wire attaches.
I don't know for sure it it coming loose was a cause or effect of damage.
You can also see the pin that holds that arm is badly bent.

Welcome to YT. I think it's pretty obvious that screw came loose. I've never seen brushes connected that way. I've only done Farmall and old car starters but that kind of screw for that connection seems like it couldn't last. I don't know where you got that starter from but that looks like a refund to me.

 

[Bob Bancroft]

I found a matching screw like the one that was loose. I holds a copper lug where the insulated wire attaches.
I don't know for sure it it coming loose was a cause or effect of damage.
You can also see the pin that holds that arm is badly bent.
View attachment 135131

That is either a metal screw or a wood screw. Either way, it's not correct. I remember that much.

 

[used red MN]

This is where those swirling copper wires were ripped off and shredded up.
View attachment 135132

Scratch my comment about it being fixable, well it actually is but probably would cost more than a rebuilt one. I also noticed later the insulation is all ripped off of the field coils in the OP left photo.

 

[Hobo,NC]

I can't remember what type of screw holds the live brush to the plastic. I don't remember if it is a machine screw or a type of self tapper. I should know because I've had plenty of them apart. But it's been 40 plus years, so I don't know. Regardless, it wouldn't be all that difficult to strip out the plastic, or force the wrong screw in there, spread and crack the plastic. It's a machine screw which holds the ground brush to the metal holder. It goes through a thin enough piece that I suppose it wouldn't be all that difficult to mess that up too.

At 16.23 that's the way I remember them on a Delco starter.