Hi
when upgrading my starter wires I managed to snap the +v connection bolt!!!
Badly rusted nut that despite heat, cutting the nut etc it still snapped the shaft and as it turned wrecked all the insulation.

a tip, put a hole in the black rubber cover so when water gets in it can drip out and prevent the nut rusting to the shaft. He also said paint over the connection to seal out water.

Now I have a new bush and shaft, but the insulation to prevent it earthing to the starter body is a problem. I will have to make some but I ask why not just solder a suitable thick wire to the new bush wire and then join the starter wire to it out side the casing? then seal up the hole to stop water etc.

So to clarify, an insulated wire will come out of the starter body and then is connected [nut & bolt] to the starter wire from the solenoid.

The advantage is that I would not have to make up some insulation solution for the +v bolt

The auto elec was not happy with that idea and said the +v bolt had to be tightly fixed to the starter body, but would not say why my idea wouldn't work.

Nigel this post might help you

viewtopic.php?f=3&t=3140&hilit=starter+motor+earth

thanks, yes I have read that thread.

Not sure if I agree with having to put a dedicated earth from the plate to the starter body.
It would seem that the earths are either dirty or not large enouge, or enough of them if this earth stap is needed.
Perhaps the bush plate is not touching the starter body enough.

I am using 4g power direct from battery and will also enlarge the earth straps, the one from the back of the motor and I may add another one.

I am into car audio and these are mods I have done to my car. [Along with many others!!] My mechanic is amazed at my earths, but so many times I read stories about cars misfiring etc ad its traced to poor earths.

Anyway i have put some shrink insulation over the bolt shaft, 4 layers, so I guess I am going to secure the bolt to the body end cap. I will use some of those red fibre washers and the auto elec gave me some insulation paper [quite thick] to silastic inside as well.

With new bushes as well, the old ones were nearly toast [worn out] after 40,000km, so hopefully the hesitation when I push the starter button will be banished for good.