It can be the starter as many said above. However, I would check all wiring making sure they're in good shape inside the insulation jacket, all ground points and connection points.
If you have access to jumper cable and can reach there, maybe try additional cable to see if it spins faster.

If you take it out, bench test it on the road to eliminate everything else, such as wiring, can help isolate the problem. Hook directly to the battery using cable you may have.

If not, I would try to go as close to some garage before tinkering too much. Corroded bolts often break where it clamps in the cable, and that's not good on the road.

If it moves, I wouldn't hit it with a hammer.

The other day, my drill press doesn't turn on because the starting circuit went bad. It's possible that the solenoid of the starter's contact area is burnt or the surface is filled with burnt up oxide layer. Give it some sand paper may help. Last time I open a solenoid, I remember it's very hard since they just hammer the case in. So it's likely destroying it by taking it apart. Maybe it's possible to test, by unhook the solenoid portion, and directly jump it over. I would think you need a very thick cable, and also I am not sure if it's doable under the truck at that high/hard to access place, but check that out if it's possible.

 

The problem does not seem to be uncommon when I look at the description




https://www.ficmrepair.com/index.cfm...rod/prd556.htm

 

Thank you for your reply. Cables are of course in good condition, I maintain the truck. I have a 240A alternator with the extra wiring.
The ground points on the frame are clean and protected with battery pole grease.

 

Interesting find on the Mean Green site.

 

The starter spins the engine at about 230 rpms.
I shorten the vacation. Dismantling the starter on the road involves too much risk, as I can't get a spare part here in the short term.
At the moment I let the truck run the whole day, cold it works without problems.
But now we can't visit anything on our vacation trip, which is of course annoying.

 

Well, if an aftermarket company says it's so ....

 

If it's spinning, the contact in the solenoid has to moving all the way.

I partially took my reman 6.4 starter apart.



The piston that pushes the gears forward.






The lever that pushes the piston forward. Nylon with a steel insert to push against the piston.





Fitment onto the solenoid.




There only is continuity to the starter motor when the solenoid is fully pulled in. So if the starter motor is running, the solenoid has to be moving freely.













So if the starter spins, the solenoid has to be fully engaged.

The rubber plug and metal insert is the pressure side of the levers pivot shaft.






Replacing the lever requires you to hold the flywheel engagement gear in the extended position.






While the plug is a loose fit, it is held in place by the solenoid.



For the lever to have excessive clearance, the screws for the solenoid would have to be backed out.

So maybe the solenoid is loose, or the pivot parts are worn.

Another possibility is an issue with the windings, but that would be the starter motor does not run when the gear is extended and engaged when hot, not enough HP. Hartwig hasn't stated if the starter "stalls" when hot, but has said it spins.

 

Thanks Jack. The starter gear is spinning "as wild" when hot and ignition is in "run" position. Batteries are always fully charged (12,8V-14V before key on, depending on sunlight) because of the photovoltaic system on the camper cabin.
Will try to take a short video tomorrow.

 

I had a 6.4 starter fail and when I took it apart, the white plastic pawl in Jack's picture was broken. I was fortunate that it happened in my shop, I now carry a spare starter and alternator in the camper when I travel.

 

So it sounds as though the gear is not being thrown forward. Maybe. With my solenoid I only got continuity when it was fully retracted. I’ve had solenoids have the contactor engage the starter motor before fully retracted, backed up by a spring. However, I don’t know if mine has a weak spring and has to be fully engaged to work or this is normal for this design.

On long trips I’ve carried an alternator and starter. They don’t take up that much room, although in the states, finding either is not that hard. But I’ve got spares on the shelf, so why not.

 

I was wrong, what broke on mine was the tip off the solenoid, not the pawl.

 

Interesting, your's is white, mine is black. I'll have to take it back apart later and see if it's nylon too.

 

Deleted. Watched video and answered my suggestion.

 

That was a "new" starter from O'Reilly with a lifetime warranty. They didn't offer the new starter any longer so I had to take a rebuilt for the replacement, which they had to order.

I bought this one off Amazon for $110 to get me by. It's still on there and working fine despite the bad reviews 2 1/2 years later and the rebuilt is my spare. The amazon starter spins noticeably faster than the old O'Reilly new unit.

 

I don't want to say that starters from Amazon or elsewhere don't work. But this truck is a vehicle that is used almost exclusively in faraway areas. So of course I try to install only the best spare parts.
The starter cost me a third of my vacation time. I have no intention of following the typical tourist routes.

I made a short video today to show the problem.
Of course, the starter worked today while filming already at the second start attempt , normally I need 4-5 start attempts.
But the last few days I have not turned off the truck during the day to avoid unnecessary start attempts.