Starter drive slips

[JimKueneman]

Rebuilt my starter during the restoration. I bought a NOS drive since I have never had good luck with aftermarket. It slipped once in a while from almost the first time I tried starting the engine (last month). Now it slips everytime I crank it over. It spins and I let go of the key and as it decelerates you can here it start to grab and the next time you hit the key it catches. What could degrade in a NOS drive to allow it to slip like that?

 

[mopar 3 B]

Heavy grease

 

[Yatzee]

Rebuilt my starter during the restoration. I bought a NOS drive since I have never had good luck with aftermarket. It slipped once in a while from almost the first time I tried starting the engine (last month). Now it slips everytime I crank it over. It spins and I let go of the key and as it decelerates you can here it start to grab and the next time you hit the key it catches. What could degrade in a NOS drive to allow it to slip like that?

Possibly the clearances of the drive gear to the flywheel. Sounds as if you've taken the edge of the teeth of the Bendix or flywheel. Off the car activate the starter to see what's going on. You can also pull the Bendix out by hand and measure the distance it travels. Don't have power connected when you do it manually. Measure the throw distance of the Bendix and then the distance required for proper engagement ( measured from the starter mounting face on the block) into the teeth of the flywheel. Compare the two and then act accordingly.

 

[JimKueneman]

Possibly the clearances of the drive gear to the flywheel. Sounds as if you've taken the edge of the teeth of the Bendix or flywheel. Off the car activate the starter to see what's going on. You can also pull the Bendix out by hand and measure the distance it travels. Don't have power connected when you do it manually. Measure the throw distance of the Bendix and then the distance required for proper engagement ( measured from the starter mounting face on the block) into the teeth of the flywheel. Compare the two and then act accordingly.

I am sure it is not tooth engagement it is the drive clutch slipping. If I keep spinning it I can hear it trying to grab more and more until it almost tries to turn the motor over. After a few experiments today if I let it slip (before, once it slipped I immediately released the key) and get it "hot" from slipping the next time I hit the key it grabs just fine. It is feeling more like it is (old) heavy grease. If I slip it the grease get warmed it and allows it to work.