The Stovebolt Site Forums The Shop Area The Electrical Bay 6V Starter (with floor pedal)... Time for rebuild?

Bright and early this morning, my truck started with no problem. Later in the day, I go to start it... It makes the initial starting sound, but never cranks the engine. Try again later, and no sound at all! The negative (battery post and battery terminal) had ZERO acid buildup. The positive (battery post and terminal) had some acid buildup, so cleaned them up- with no change. Does this mean it's time for a starter rebuild/replacement?

I was reading some posts, that some starters have brushes... Is this true? Does mine? I get why generators do, but starters... Really?!

You need the special part that Hotrod (Jerry) developed. A plastic Coke cap. It fits over the round button (actuator) at the starter. If you linkage has too much slop, this gets you by until you have time to fix it.

Buoymaker- Will try the Coke cap! But how do I fix the linkage-slop problem, otherwise?

Decades of starts will wear all the pivot points where the linkage moves. You'll need to disassemble things and look for wear grooves, oblong holes, etc. Weld, fabricate bushings, or do whatever it takes to get the linkage moving everything like it did back in the dark ages.

It's also possible that there's a "dead spot" on the starter armature that creates an open circuit when it stops in the wrong place, or worn brushes that aren't seating properly on the armature. Try a few gentle taps with a medium-sized ball peen hammer to the back end of the starter housing and try the pedal again.
Jerry

I was having fun but seriously wear is a lot of what happens. We first need to isolate if it's the linkage or the starter itself.
Put the truck in neutral, apply parking brakes, ignition switch "on" then push down the round starter actuator with something like a screwdriver.
Report back on what happens.

There are plenty of "brushless" electric motors, but they're not used for starting engines, and most of them run on AC current. I serviced them for a lot of years in industrial applications, up to 100 HP or more.
jerry

There are DC brushless motors as well. I have a battery operated impact driver that's brushless. But things like that didn't exist in the '50's, and definitely not for starter motors.

Hotrod Lincoln- I'll check that out. I did tap it with a hammer, but at the front, not the back... No change. I'll try the back this time.

Bartamos- How would I automatically know that the starter has brushes? As far as I knew, all it did (when pushing the floor pedal) was push the pinion shaft to the flywheel, and with supplied electricity- start the motor. Like I said, brushes in the generator make sense, because it's recharging the battery.

Buoymaker- "Wear is a lot of what happens" makes sense. I did try pushing the actuator... I both heard and felt buzzing.

I forgot to mention in my OP, but I measured the voltage in the battery after said discovery. It was just barely above 5 volts. I don't know if that'll change much, but I'm going to charge the battery and try again.

A fully charged battery will make the difference in 6 volt.
Also double check all of your Grounds.
Keep us posted.
Todd

Open circuit (no load) voltage of a fully charged 6V battery should be around 6.3 volts, 2.1V per cell. Try monitoring the voltage at the battery posts while someone else pushes the starter pedal. If it drops below about 4.5 volts under load, you've either got a discharged battery or one that's got an open circuit inside one of the cells and must be replaced. A good 6V battery should be able to crank the engine at normal starting speed for at least 15 seconds without the terminal voltage dropping below 4.5.
Good luck!
Jerry

On 7/21/21 I charged the battery for 30-45 minutes, which was enough for the starter. On the drive home (10-15 min), the gauge indicated charging. Earlier today 7/23/21, I checked the battery, and it was @ 6.3V (not running). So for kicks and giggles, I checked it running... It went from 6.3V up to 8V (because it was still charging).

So at this point in time, I guess it's safe to say it's not the starter, or linkage slop. When I replaced the frame to battery cable (years ago), it still had bare metal, so I doubt it's that ground. I haven't replaced the braided frame to starter ground cable yet, but if its kept up like the former, I doubt it's that ground either. I replaced the battery to starter cable (provided that's the one that HAS to be 1 gauge), years ago, and when I did- I applied Dielectric grease to the starter connections.

So if I read correctly, the truck has since started and is now running. You checked the battery voltage and it is now 6.3V (not running) and 8V charging (running).
Just to be on the safe side, I would take the truck or battery to your local parts store and have them check it with their load tester.
If the starting problem happens again, you can eliminate the battery.

8V is a bit too high. You'll end up boiling the cells dry on a long haul drive. The recommended upper limit for a 6V charging system is 7.5 volts, which is adjusted by changing the spring tension on the set of points behind the "F" terminal of the regulator. Lower tension- - - -lower voltage. Always adjust a regulator against a fully-charged battery- - - -overnight on the charger at least before trying any adjustments.

A quick battery test can be done at home. With the ignition switch off, crank the engine for 15 seconds. Check the battery terminal voltage while still cranking. A good 6V battery should not drop below 4.5 volts after 15 seconds of cranking and it should return to 6 volts or more of terminal voltage when the cranking stops.
Jerry

Buoymaker- Yes, it has since started and ran. And also yes, to the 6.3V and 8V.

Hotrod Lincoln- Will test tomorrow.

Hotrod lincoln- Battery & starter are good, even after 2 tests. Both times, never dropped below 5V. And even after the second test, it dropped from 6.3V to 6V (not cranking).

I have started my 1950 3600 from under the hood. With the key set to on, truck in neutral with the parking brake on, then use a pry bar to depress the button on the starter from under the hood. This will identify if you have slop in the linkage or perhaps the contacts in the starter mounted switch have eroded away enough to require a bit more travel than the worn linkage can provide.