Starter motor not kicking back apon startup

[VTSSDUDE]

Hi All,
Having an issue with starter motor in my VS 5L litre.
I can wind the motor over no troubles, but when the motor starts, it's like the starter cog isn't being thrown back down hard enough and makes that squarking sound as if you were trying to start it when the motor is already running.
I have removed the starter motor, works fine when it is on the bench. I have pulled apart the reduction drive, didn't seem to be clogged up, but I cleaned it out and oil it all.
Still the same problem.
Funny thing is, two weeks ago it started doing this, I removed the start motor and oiled the shaft the cog is on, put it back in and it worked fine until a few days ago. After yesterday when I removed the starter motor, pulled it all apart and cleaned it, it started no problems for a while then the noise came back.
No major burrs on the flywheel and the cog looks okay.
Any ideas anyone?

Thanks,

 

[hako]

Make sure the nose of the pinion gear isn't worn where it first meshes with the ring gear...it should be nice and smooth so it meshes....no broken squared off shoulders - the shaft the pinion slides on should not be oiled as it attracts dust/dirt and sticks/jams - check there isn't an adustment for the throw of the solenoid which adjusts how far the pinion slides before it makes electrical contact and the starter spins - check the ring gear is not loose on the flywheel and the ring gear teeth are not worn - check the small connector to the top of the solenoid is not loose...it needs to be tight.

The above you've probably checked already my prime guess would be the oil on the shaft.....as well as attracting dust/dirt the oil will rapidly dry out as it's in a hot environment leaving a sticky residue.
Hope this helps. Good Luck.

 

[VTSSDUDE]

Thanks for the tips, the pinion cog doesn't look worn, but it the edges are rounded. I will remove the oil off the shaft, I didn't think about attracting dirt.

 

[markovr]

I had a similar drama with my vp after I changed the battery...pulled everything apart and it all looked good but the drama persisted....as a long shot after pulling it apart again I put a smear of graphite grease on the gear teeth....never had any dramas since and that was years ago.

 

[VTSSDUDE]

Mmm, makes sense. Thank you, I will give that shot.

 

[hako]

Another possibility is that the starter motor is not properly seated into the bell housing....slightly cocked - can cause jamming as the pinion meshes with the ring gear at an angle.
Re the edges of the pinion being rounded - check a new one as I think they have a definite angle chamfered on them designed to help it mesh.

found this at northatlan.com:
A starter drive includes a pinion gear set that meshes with the flywheel ring gear on the engine's crankshaft.To prevent damage to the pinion gear or the ring gear, the pinion gear must mesh with the ring gear before the starter motor rotates. To help assure smooth engagement, the end of the pinion gear is tapered.