I just got inside a starter for the first and it went great.
Replaced the brushes on my '63 223 F100 and it transformed the cranking.

Now, my '83 F250 6.9 diesel exhibits the same symptoms and I'd like to get inside the starter and inspect the brushes.
I'm pretty sure the cause of the slow cranking is internal to the starter, electrical, and most likely loss of brush tension due to wear.

It looks trickier than the other one though.
The old starter I just worked on had a removable cover where I was able to inspect the brushes and reset the brush springs after reassembly,
but the 6.9 starter looks like a closed case and I'm kind of afraid to just pull it apart, blind.
I wondered if there are important techniques to use: getting it apart, changing the brushes, and reassembling that someone in this forum might have experience with.

If you believe it is better to replace the starter, you could start a thread to weigh the pros and cons.
I hope to confine this discussion to actually opening these up and doing the work

NAPA tells me they can get the brushes in one day (looks like none are soldered to the motor windings like the 223, thank god)
Thanks,
Dale

 

I was starting to do this on my 7.3 starter and then stopped because I couldn't find the brushes. Do you have a NAPA part number for them? I need to replace the solenoid and some hardware also but I can source all that separately. My brushes were pretty much worn down to nothing and I replaced the starter with a DB unit and was hoping to have this available as a spare.

 

They come apart very easily. Pull the two screws at the back cap on the motor, those old the brush plate to the back cap and are what grounds them to the starter frame and on to the engine. Disconnect the lead from the starter motor to the solenoid, then pull the two long bolts that run down the sides of the starter motor. Some light tapping may be required to separate the back cap from the motor frame, and the motor frame from the reduction housing, but otherwise it just drops apart.
When putting it back together, clean the inside of the back cap and the outer side of the brush plate thoroughly with a wire brush, and maybe put some dielectric grease or conductive anti seize on there. Replace the screws with allen head ones so you can get some actual torque on them and still get it apart next time. I have fixed two starters with just this.
The Napa brushes are Echlin part ECH E511 for the Mitsu starter, and ECH R509 for the direct drive starter. The also have the Nippondenso ones for $170.

 

Excellent! Thank you. Do these get soldered on to the harness they sit in? Any tricks to get it done?
Thanks again.

 

I still had the starter, which is Mitsubishi, coated with solvent when I posted originally.
I cleaned it up this morning and examined it.
Disassembly looked pretty straightforward, so I plunged in.
I detached the motor from the outdrive and removed the brush cap.
Everything looked about as I expected, except I wouldn't call the gear reduction planetary.
It is ring and pinion with internally toothed ring.

I can't tell you the NAPA part number now, but it looks like someone has already.
It is a special order part from here, (Bloomington IN.)
As for soldering, the NAPA brush I saw illustrated would be soldered to the lead.
I found one (by Mitsubishi starter PN) listed on ebay for this application that had a lead, so maybe it is your choice.

I haven't ordered parts because I'm concerned about other observable electrical issues inside my starter.
If rebuilt, the brushes should be replaced, but they aren't worn quite to the point that spring action is impeded.
The operational problem on this one lies elsewhere.
One commutator pole is badly pitted, there is some other small physical damage to the outboard end of another pole, and a couple of small solder spheres stuck to the inboard side, so it may not be rebuildable.

I'm going to press on with it, though, until I'm certain.

Dale