Starter motor rebuild - refitting brushes

[orangebooboobearcrew]

Hi,

Still working through the starter problem on our 1980 2.0l Aircooled and after having replaced the main cable from the battery (slight improvement) decided to strip the starter following posts read on here to see if I could see any internal issues.

There was nothing really obvious on the internals, the commutator was a little dirty, but not too bad, so I cleaned it with a quick sand and also cleaned out the grooves.

There seems plenty of meat on the brushes and the braided wire from the solenoid all looks fine (as I would have hoped as starter only a couple of years old with limited use (reconditioned)).

Now to put it all back together, is there a trick to getting the brushes back over the commutator as I have tried for quite a while now with no success?

Thanks gang,

Chris

[Fudgy666]

Is there a trick to getting the brushes back over the commutator as I have tried for quite a while now with no success?
s

Sorry I'm no help with this I'm afraid, but just a reminder (Only on the off chance it's been overlooked). If you've already got the starter out and it's been giving you problems, remember to replace the starter motor bush in the Bell Housing. Back when I was having starter motor issues I replaced mine and noticed a definite improvement.

[CovKid]

No idea what the fault is but could well be solenoid if its hit and miss. Agree on starter bush too.

[orangebooboobearcrew]

Is there a trick to getting the brushes back over the commutator as I have tried for quite a while now with no success?
s

Sorry I'm no help with this I'm afraid, but just a reminder (Only on the off chance it's been overlooked). If you've already got the starter out and it's been giving you problems, remember to replace the starter motor bush in the Bell Housing. Back when I was having starter motor issues I replaced mine and noticed a definite improvement.

Hi, thanks for your quick response and helpful suggestion. I have indeed purchased the new bush and it is ready for soaking in oil ready for insertion. Got the old one stripped out ready...

No idea what the fault is but could well be solenoid if its hit and miss. Agree on starter bush too.

Hi Covkid - as you are the guru on starters, I was hoping you might have some golden nuggat of knowledge on how to keep the brushes held back so the brush box can be slipped back over the commutator - I have been seriously struggling with it.
Also, is there a way of testing the soleniod or is it worth me trying to find a replacement / is it easy to change?

Cheers Chris

[orangebooboobearcrew]

Also, is it worth me changing the trigger wire whilst I've got the starter off? If so, what is the correct gauge to get for replacement and any idea of length?

[CovKid]

As long as you're getting 12v there and the spade is good or new, I'd leave it be. The downside of rebuilding a starter (and there aren't many to be honest) is if the solenoid needs replacing the screws may not move even with an impact driver. Its a vice job for sure. The solenoid is under £20 but getting the old one off can be troublesome: http://www.ebay.co.uk/sch/i.html?_from= ... d&_sacat=0" onclick="window.open(this.href);return false;

Solenoid faults can vary from 'no go' to 'I'm going but not particularly well' - depending on how much current its able to deliver - in a nutshell. Mind you, a duff starter bush (cheap) can produce similar sluggish results.

Personally I change the solenoid screws for bolts - easier to deal with in future.

You may find this useful: https://www.youtube.com/watch?v=wjguw4n6MBk" onclick="window.open(this.href);return false; - different starter but similar principles.

Finally, DO NOT test the starter off the vehicle. Without it installed and fitted in oilite bush, you run the risk of killing starter bearings.

[colinthefox]

Now to put it all back together, is there a trick to getting the brushes back over the commutator as I have tried for quite a while now with no success?

You can use a hooked piece of wire to pull back the springs one by one and slip them down the side of the brushes to hold them in place in the "raised" position. Then when the brushes are over the commutator, you can put the springs back in the right place.

Easier said than done, I know.

[orangebooboobearcrew]

Quick update.

Firstly thanks for all the quick and very helpful replies.

Tonight I have managed to get the brush box back on! Just used a flat bladed screwdriver and held back each brush in turn so that it was touching the commutator top, then went round again easing them down a bit more, then eventually they all clicked into place.

I also managed to loosen all 3 star bolts (?) on the front of the solenoid so I think it would come off ok if needed.

If it is getting 12v and I can hear it click every time the ignition is switched, does this mean it is ok or could it still be suspect?

My concern is I haven't really found the cause yet. Main wiring change has made a slight difference to my slow starter but not cured it, I've replaced the gearbox / body earth strap, cleaned all connectors, the starter internals didn't show any broken wires, excessively worn brushes or excessively dirty / damaged commutator.

I still have oilite bush to do but the one I removed hasn't been in for more than a couple of years use and I've probably done <10k miles so presume it wouldn't be too worn?

What about the bearing on the 'nose' of the pinion shaft - should this wobble or is this wear to be replaced.

Maybe a tight or partially seized engine so will test that by turning with spark plugs out once starter back on.

I may change battery post terminals and check earth at battery isnt corroded but I presume if it was I would be getting issues with electrical components not earthing correctly as well?

Any thoughts appreciated...

Ta, Chris

[jpennington]

Checking the solenoid.
If you remove it from the starter motor you can do a couple of checks.
1. Apply 12v between the spade terminal and the threaded terminal that was connected to the brushes. You just need to touch a wire onto the spade and the solenoid should activate with a very solid thwack.
You say you can hear it click so I expect this check will work fine.

2. A likely problem is that the main contacts inside the solenoid are corroded. I tested this using a multimeter on ohms to measure the resistance across the two threaded terminals. I pressed the solenoid body in by hand against the spring pressure and noted the resistance. In my case this varied from 20 ohms to about 0.2 ohms. It should, of course, be zero ohms. Try it several times - if you don't get a good contact (0 ohms) every time, then your solenoid may be past it.

Replacements are about £25 on ebay.

See this for pix of my old solenoid https://club8090.co.uk/forum/viewtopic.p ... 6#p8088037" onclick="window.open(this.href);return false;

jp

[orangebooboobearcrew]

Checking the solenoid.
If you remove it from the starter motor you can do a couple of checks.
1. Apply 12v between the spade terminal and the threaded terminal that was connected to the brushes. You just need to touch a wire onto the spade and the solenoid should activate with a very solid thwack.
You say you can hear it click so I expect this check will work fine.

2. A likely problem is that the main contacts inside the solenoid are corroded. I tested this using a multimeter on ohms to measure the resistance across the two threaded terminals. I pressed the solenoid body in by hand against the spring pressure and noted the resistance. In my case this varied from 20 ohms to about 0.2 ohms. It should, of course, be zero ohms. Try it several times - if you don't get a good contact (0 ohms) every time, then your solenoid may be past it.

Replacements are about £25 on ebay.

See this for pix of my old solenoid https://club8090.co.uk/forum/viewtopic.p ... 6#p8088037" onclick="window.open(this.href);return false;

jp

Thanks for this. I will try both test, however I think I do hear it clear every time I turn the key, the issue seems to be more one of the starter not being able or struggling to turn but just need to keep fault finding...

I presume I can't test the solenoid whilst it is still attached to the starter but off the vehicle?

Thanks,

Chris F

[orangebooboobearcrew]

Also, per my earlier post, has anyone had any issue with the 'bearing' on the nose of the armature shaft causing pinion gear engagement issues?

This wobbles quite a lot on mine and spins around freely. Is this likely to be an issue do you reckon?

Thanks,

Chris F

[jpennington]

I presume I can't test the solenoid whilst it is still attached to the starter but off the vehicle?

Correct. You need to remove the braided wire to the brushes, take out the 3 torx screws and unhook the solenoid from the pinion actuating lever.
jp

[Oldiebut goodie]

Surely you can still check it same as on the engine with the power removed - you aren't actuating the starter as long as there is no power to the motor. You are not rotating the motor just actuating the plunger. It is only a solenoid which will work on or off the motor. Off the engine you can check the throw which is an advantage if there is a sticking point on the shaft.

[orangebooboobearcrew]

Surely you can still check it same as on the engine with the power removed - you aren't actuating the starter as long as there is no power to the motor. You are not rotating the motor just actuating the plunger. It is only a solenoid which will work on or off the motor. Off the engine you can check the throw which is an advantage if there is a sticking point on the shaft.

Yes, this was kinda what I was thinking tbh to save dismantling the solenoid from the motor just power up the solenoid only and not the starter terminal...?

[orangebooboobearcrew]

So to be clear, do I put 12v positive on the spade then negative return to battery from the braided terminal?