A really eff'd up ISB issue

Alex Bruene · April 22, 2013

Here's the deal... We have a customer with a 2011 F-650 with an ISB Cummins. Every few months, he will tow it in as a no-crank. The starter does not engage. All you hear is the relay clicking. If you bar the engine over a c*nt-hair, then it will work perfectly fine, and continue to work perfectly fine for months. We have verified the starter drive is not engaged to the flywheel. Does anybody have guess as to what might be happening to cause this, and what turning the crank pulley does to make it crank again?

Buddy_M · April 22, 2013

Bad(flat) spot on the ring gear teeth in a spot so the drive/ring gear so the ring gear/drive are hitting and not engaging completely? Barring it over allows the drive to fall inbetween two ring gear teeth instead of hitting head on maybe? If it were me, I'd inspect every tooth on the ring gear and possibly hang a new starter suspecting a drive or solenoid problem.

Alex Bruene · April 23, 2013

I was sort of wondering if something with the ring gear causing an issue, but it really doesn't feel like the starter is doing anything (with my hand on the starter) at all when then no-crank issue is present. ISB engines DO have a recall on the flywheel. We may have to look in to that.

Keith Browning · April 23, 2013

I was sure that the FLYWHEEL is actually a FORD componant or at least at wit Cat engines it was as stupid as that sounds. A few years back I had a 750 with a broken ring gear. Cat did not pay for it nor did Allison. Finally got the claim paid by ford after a long battle.

Just thought I would mention this - Cummins might be different and I am betting they are if there is a recall which i heard about last week but have found nothing on Ford's site on it. Maybe later I can check the Cummins site... Got the engine serial number?

Keith Browning · April 23, 2013

I doubt there is any relation between this issue and the recall but I am attaching the bulletin for you to read. If the starter is not energizing then why would you suspect the flywheel? Sounds electrical to me. Why does barring the engine correct the concern? Beats me but what ware you disturbing to do that?

Alex Bruene · April 23, 2013

Keith, I don't know if the starter is energizing when it won't start, and right now, the concern is no longer present. I am getting my info from the tech working on it. I just can't see what else can have any relation to the engine turning. You can easily get to the crank pulley without touching anything at all, so I imagine nothing else has been disturbed. I have QSOL access, and from what I can determine, the flywheel belongs to Cummins.