Please see here 6 photos of a Lucas Starter Motor for a Massey 3090 Tractor. Partly disassembled and in the condition pictured. Starter intermittently failed - used lots of amps - and failed in the end. All four brushes are relatively stuck and the copper part they are meant to contact is dirty. This is the first starter motor I have pulled apart out of necessity. What advice can you give in relation to what procedures to follow in cleaning it up and what not to do? The field coils inside the cylinder have bits of plastic falling off and lots of rust on the surface??? Should I remove them? How would I clean them? What surface treatment should I give if anything at all? Obviously brushes need to be freed up and some protective surface given - just fish oil or gal paint??? Any advice/experience gratefully received. MX45
Photo 6
I have successfully rebuilt my own starters and alternators for years but I doubt have ever worked on one exactly like yours. As a rule the windings in the stator and rotor are coated with epoxy and if you see the coating breaking down you need the services of a rebuild shop. Could that be the bits of plastic that you see flaking off? All of the connections to the battery, ground and the solenoid are the first to check. Batteries can fail in many different ways and can fool you. If that one were mine I would probably replace the brush holder because it looks terrible and the starter drive by routine. The bushings if needed. If the windings overheated and shed epoxy, rebuild shop. I have never owned a megger to check windings. I am guessing that worn out and stuck brushes are your main problem.
Clean it all up, sand paper, wire brush, a cleaning fluid that dries. The brushes look to be sticking out both ends of the holders so they are not worn. What you do nee to do is clean out the insulation in between the segments where the brushes run on the armature. This can be a pain in the but depending on how hard the stuff is. How i do it is to grind a hacksaw blade to act like a single ripper tine. Then tape the blade so it does not hurt my hand. Then with the armature in a vice then you have to rip out about .5mm of that insulation. At the moment the brushes are running on the insulation and not the copper of the armature. It is copper so you need to be careful, your little ripper need to have a cutting edge the width of the hacksaw blade not a point or it will just dig into but not rip out the stuff. As the armature segments are copper if the insulation is hard your tool will want to slip off and dig into the copper so be careful. You may need to get the armature put in a lathe and clean up the segments. Tried to explain as best I can , hope it makes some sense. For the insulation on the field windings i would just clean it after you have cleaned it up. If you need field or armature I would be going a new unit.
Result! Well fellas thanks for your input. Cleaned up the brush plate with wire brush, screwdriver and treated with fish oil and gal paint. Kept clear of the two insulated plates for the two insulated brushes. Just blew out the coils inside the armature and clipped off the plastic - I am certain it is the plastic insulation as the starter is circa 1989! Insulated with RTV the exposed wires I could see. Brushed rust and treated with fish oil. Filed the rust away inside the brush holders - all were rusted tight - quite a trick to get them out without breaking them but some patience and WD Rust breaker worked. Removed springs and soaked in fish oil and again treated with cold gal paint. Biggest source of problem seemed to be the failed seals on each end of the starter which allowed water in or condensation??? I sealed with RTV Silicone to keep it clean. Never stored under cover by previous owner so probably inherited the problem. Cleaned brush rotary end of starter with emery cloth and scraped insulation with point of a fine file.
OH and it works at least twice as well as what it did before so all that solenoid repair and new battery was not the cause of my problems as advised by Auto Electricians????? So if you have a starter problem simply pull it and look at it - it could be like mine, Regards, MX45
Good job, If you take a starter or alternator into a Auto sparky these days they pull it apart and tell you it is stuffed. then the try to sell you a new aftermarket one out of there catalog which will not quite fit . sandy
They always say "solenoid and bendix", and if you listen a minute you can hear that they don't know a solenoid from a starter drive. It seems a starter drive is one of the great mysteries of the mechanical world. I'm lucky, for the time being I have access to a well stocked, good old fashioned starter and alternator repair shop whose owner sells me reasonably priced parts. I guess it is a rare thing these days. Nice work on that brush plate.
Good work MX45! Most sparkies would take one look at those first pics & say "it's not worth fixing". That's what I even thought.......
Well my starting point was the starter motor was not working and likely would need reconditioning/new - which is lots of money. So the worst that could happen was that the starter motor would not work after I had a go at fixing it - so nothing to lose except some time and effort! Thanks for the responses. I think I was told quite a few hundred dollars to look at it - plus parts - and lots of stuff made today is not as good as that made yesterday and meant to be serviced - disposable stuff - so worth it to have something tried and true. There was no money to be had as a young fella and so you fix it or you dont have it! As much as I would like not to have skinned knuckles and filthy hands there is a certain pleasure in not being ripped off! Regards MX45
What are you calling fish oil? We called fork oil from old japanese motorcycles "fish oil". Some people take fish oil pills, like vitamins. No fish oil for cleaning parts here.
Fish Oil is a common antirust supply in Australia that comes in cans or spray cans and is applied as an agent to soak into the metal land provide a protective surface coating. I usually apply cold gal paint (zinc rich) to provide protection. If it were an outside piece to be protected I would then epoxy over the top and mix some fish oil in the epoxy paint. I have found this to work as a preventative for returning rust so long as the surface preparation has been done well. I am guessing it is exactly what they say it is - fish oil! MX45