Starter disengaging too soon

[donradcliffe]

Take it back to the professional and explain your problem. I once had a starter that worked fine in the starter shop and not in the boat. I took it back and told him to spend another hour on it. Problem solved.

[Stu Jackson]

Originally Posted by donradcliffe

Take it back to the professional and explain your problem. I once had a starter that worked fine in the starter shop and not in the boat. I took it back and told him to spend another hour on it. Problem solved.

Have you at the very least called the person who did the work and shared your experience with them?

[deblen]

Originally Posted by ProjectManaia

So with all the feedback my current (best) bet would be this:
The starter was serviced about a week ago, so all was greased and oiled etc. So maybe the little gear simply jumps back too easy. Our starter does not have the "switch solenoid" on the side, there is a solenoid connection on the main cylinder of the starter, so from the drawings I think the momentum of the turn of the starter motor is pushing the gear into place with a worm drive. So that the only reason for it to stop engaging really could be bad contact somewhere, so yesterday I cleaned all contacts nicely and recrimped everything that looked questionable. Since then 4 starts ran without any issues.... yet to be found out if it solved the problem for good though....
Thank you all for the feedback!

I think you may be describing a "Motorcraft" style starter system. The electric solenoid is mounted remotely from the starter motor. The starter motor has a wedge shaped cover over the bendix actuating mechanism. A strong electromagnet pulls this mechanism,which pushes the bendix forward.
Take wedge cover off,temporarily, to see if mechanism is working freely.
A common problem with these starters in 70's-the stud where you connect the heavy pos. cable on motor stretched.The bolt & nut were made of copper.
You had to double nut them. Also,the head of this stud,inside the starter,would melt free of the internal soldered connection.
The best cure is replace the starter.
See attachments:
Cheers/Len
https://www.hemmings.com/stories/art...craft-starters
https://classicbroncos.com/forums/th...ighten.138730/
https://forums.yesterdaystractors.co...arter.1586869/

[Scubaseas]

My $.02 on Motorcraft style starters from way too many years pushing a wrench and in light of you description, my guess would be in order of probability:

1: Bendix (AKA one way gear, sprague gear). Even new ones can be stiff for a few times. Or bushing inside it is worn. also check the "fork" for the bendix being worn. Presume your rebuilder checked these. Take the oval cover off the starter to inspect but ask the rebuilder if it's OK for you to do that without voiding any warranty you have with him.

2: Worn end shaft bushing. There are oilite bushings on both ends of the armature/ starter shaft. Don't know your design but some are in the bell housing. Your symptoms were a common complaint on air cooled VWs that used this setup if the bushing was worn or missing.

3: Damaged tooth/teeth on ring gear. If you have the starter motor out you can check each tooth. There's lots of teeth and you may need a mirror on stick or endoscope. I have videoed the teeth while hand turning the engine, loosen decompression levers if the engine has them or loosen glow plugs or injectors to make it easier to turn over if you need to.

BUT

I'd talk to the guy that rebuilt the starter and ask him if bringing it back in might be possible. Bendix or fork is most likely in light of stated symptoms IMHO.

[IOM]

I think the best is to post a picture of the starter, and the starter" gear" section.
Ford were notorious for having an inertia bendix engagement system which did exactly this, and when the engine never started and ran after the first cylinder fired and the next one failed to fire, the starter carried on running but was no longer engaged to the ringgear.

The solenoid only acted as a motor switch, and had no mechanical connection to the bendix

[bony]

Originally Posted by flightlead404

concur, this does not sound electrical to me.

I have had my share of starter problems.

I wonder if you've ever had the problem I had a few months ago. It was the first time I ever encountered it.

It was a petrol motor and I turned the ignition key to start position, starter motor began to crank the engine, engine fired and ran ok, but when I let go the key the starter kept cranking. I turned the ignition key right off, so no more spark or ingnition in the cylinders, but engine kept turning because starter motor was still engaged and spinning. I had to disconnect the battery to stop engine and starter from spinning.

The problem simply turned out to be dirty contacts in the solenoid points causing an electrical short to keep the starter running and thereby preventing the Bendix gear from retracting. I dismantled the solenoid, cleaned the contacts with sandpaper, and all was good again.

Starter motor solenoid points are most always neglected for years and can do all sorts of crazy things when they get dirty or worn. I wouldn't rule out an electrical issue for the op's problem.