Alton starter

Gilesy

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I know there is a lot of information regarding these already but I can't seem to find anything like this. The starter has failed owing to the 3 plastic rods disintegrating
alton starter.jpg
. On inspection there is what appears to be a crude weld holding the shaft into the gear wheel. It has failed, but I'm curious to know its function. It can't be designed to take any force as it is so flimsy. Do you think I could use Loctite 638 retaining compound to secure it. My kit came with 3 spare plastic rods so I could get it going again fairly quickly without having to deal with Alton. The kit came new, but is now out of warranty. It has been great so far. Any help appreciated.
 

Gilesy

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Yes. but more of a 'tack' than a weld.
 
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cliffa

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It does look pretty poor I have to say. I'd take it somewhere and have it welded properly.
 
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I presume the weld is to locate the gear in the correct position on the shaft and, as you say, it doesn't transmit any force so the weld isn't under much stress so is strange that it has failed. A little dab of weld would probably be all it needs to fix it.
Those plastic things are like shear pins and designed to break rather than any mechanical damage occur when some sort of overload condition occurs. Mine were fine for ages but broke when the battery got low so that starter was struggling to turn engine over.

RGM sell some Alton spares and do have the plastic things. They also have that shaft but you have to buy the other part that fits on that shaft with it, which makes it quite expensive.

 

Gilesy

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I presume the weld is to locate the gear in the correct position on the shaft and, as you say, it doesn't transmit any force so the weld isn't under much stress so is strange that it has failed. A little dab of weld would probably be all it needs to fix it.
Those plastic things are like shear pins and designed to break rather than any mechanical damage occur when some sort of overload condition occurs. Mine were fine for ages but broke when the battery got low so that starter was struggling to turn engine over.

RGM sell some Alton spares and do have the plastic things. They also have that shaft but you have to buy the other part that fits on that shaft with it, which makes it quite expensive.

Thanks for that, you have confirmed my suspicions. I think I will use the Loctite, it is amazingly strong in this type of application, certainly stronger than a tack of weld. I will order some more plastic cylinder things, To use 3 or 6, that is the question.
Cheers
 
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"
To use 3 or 6, that is the question.
Cheers"

Isn't it shown in the Alton instructions?

Loctite stronger than a weld? I don't know about that. I've had red loctite fail in simply holding a Norton rear-view mirror onto the OEM Norton mirror mount-unscrewed with vibration.
 

baz

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"
To use 3 or 6, that is the question.
Cheers"

Isn't it shown in the Alton instructions?

Loctite stronger than a weld? I don't know about that. I've had red loctite fail in simply holding a Norton rear-view mirror onto the OEM Norton mirror mount-unscrewed with vibration.
6 in mine from memory
 

baz

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Thanks for that, you have confirmed my suspicions. I think I will use the Loctite, it is amazingly strong in this type of application, certainly stronger than a tack of weld. I will order some more plastic cylinder things, To use 3 or 6, that is the question.
Cheers
I'd definitely weld it
But then I'm a welder!
Where in the country are you?
 
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Thanks for that, you have confirmed my suspicions. I think I will use the Loctite, it is amazingly strong in this type of application, certainly stronger than a tack of weld. I will order some more plastic cylinder things, To use 3 or 6, that is the question.
Cheers
I'd go with welding too.

You should use 3 of those plastic slugs. If something bad happened it's better that they shear rather than destroying something expensive.
 

Derek Wilson

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I would be contacting Alton for a replacement before doing anything. They are pretty good about warranting this type of thing, especially if it looks like a quality issue.

As an aside, the weld does not take any significant torque, it is there to locate the gear on the shaft. Depending on the fit of the shaft in the gear (it should be tight), it may end up being loaded in bending if it is a loose fit.
 

Gilesy

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All back together and working OK. I used the Loctite, the weld came apart when I gently tapped the shaft to split the cups. I stuck an intermediate gear shaft into a crankcase as there was a very small amount of play. Some time later I decided to replace it but there was no way it was coming apart even using a lots of heat and brute force, It is there to this day. Anyway thanks for all your suggestions. Sometimes you think you know the answer but it's always good to ask others what they think.
Cheers
Giles
PS Baz, I am in south Devon.
 
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My tack weld also failed. It really only keeps the shaft from walking out of the gear wheel. I rewelded it and am good to go.
 
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this might be a late add to the thread, but a year or so ago, i thought i read on the fourm that McMaster-Carr had the same polyurethane rod material that's used in the alton starter assembly. i'm somewhat thinking this is what was called out. does any know the diameter of the alton shear pins - 3/8" or 10mm? since the starter is euro sourced, i would think 10mm. can anyone verify? i used my 3 spares, and need replacements. shipping on the 6 from RGM is a bit crazy here to the U.S.

 
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"
To use 3 or 6, that is the question.
Cheers"

Isn't it shown in the Alton instructions?

Loctite stronger than a weld? I don't know about that. I've had red loctite fail in simply holding a Norton rear-view mirror onto the OEM Norton mirror mount-unscrewed with vibration.
This is a statement directly from Paul at Alton.

"We fit normally 3 as standard but some « heavy duty » engines require 4, 5 or 6 inserts (hence the 6 slots)."
 
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can anyone measure the diameter of the poly inserts? are they 3/8" or 10mm diameter?
 
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They are 10 mm diameter and 12mm long
thanks baz - got to eat crow on this one. i didn't have any spares after my two woodruff key failures, so i bought a section of poly rod and fab'd my own. problem is, i used 3/8" rod (.375 ) whereas should have known better and used 10mm (.3937) - that's a difference in diameter of .0187" and enough of a difference, that i ate through those slightly smaller pieces after about a dozen starts. lesson learned, problem is, i've got to tear into the alton assembly again. this will be my third time, and hopefully the third time's a charm! based on brutis61's post, i might try adding a forth shear pin.
 
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Why would those pins continue to fail? Seems as though there must be some issue that is causing excessive stress on them.
 
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