Air Shut off

[ArtGill]

We had the blower shaft out and the drive gear and didn't see any damage.  When we rolled the drive shaft with our fingers the blower turned smooth.  Also, there was no metal chips.  It is from my old memory, but I think it is more likely my shaft is a 24 spline shaft. 

Do you think it will show up again in a short drive?

Thanks, Art

[Geoff]

There is a world of difference between the two quill shafts.  The 48 spline is a fine thread while the 24 tooth is chunky.  I am going from memory here on the exact spline count, but the two different splines are like night and day.  You have to have a lot of experience to tell if the fine spline shaft is worn out enough to cause slipping, but there isn't anything else that can cause the problems you describe.

[ArtGill]

I confirmed with my mechanic that the shaft had course spline.   It acted, except the noise, that I ran out of fuel for a moment and it sucked some air.  My parking spot is concrete and level.  But the forward motion could have pulled the fuel away from the dip tube.  According to my mileage since fill up, I should have half of tank.  But the coach was at a shop for 6 weeks.  So, my next project is going to be a confirmation of fuel level.  I really hope it is an low fuel problem instead of being an unknown problem that will reappear at the worst time.

Art

[sledhead]

maybe some kind of locking fuel cap might solve the problem ?

dave

[luvrbus]

Could be the yoke on the fuel pump drive is starting to round out

[Geoff]

The first post said  it tried to start wouldn't catch, and had black smoke.  And this after a "loud snap".  I'm back to the alternator drive.  The drive could have broken and fallen into the gear train and wiped it out throwing​ the timing off.

Not good.

--Geoff

[Geoff]

Double post.
--Geoff

[luvrbus]

He can check for a broken alternator drive with a volt meter can he not,those heavy 50D alternators will snap a cam,he says it running good now. It is a DDEC engine a Pro/Link would show timing problems 

[ArtGill]

I'm at a loss also.  I may check the fuel pump yoke before I bolt down the DDEC and exhaust pipes.  The alternator is charging and the engine is running good.  I need to go and get a NC safety inspection and will need to go over a steep bridge over the ICW.  This will tell me if I have a power problem.  But first I'm going to confirm I don't have a low fuel problem. 

I don't like not knowing what the original problem was/is? 

Art

[buswarrior]

Focus on the NC Safety, nothing worse than being sidelined mechanically, AND administratively!

Quite the insult to get a ticket for expired tags while trying to roadtest problems...

happy coaching!
buswarrior

[Iceni John]

Whether this recent issue was fuel-related or not, it may be a good time to consider installing trustworthy fuel level and fuel pressure gauges, and maybe also a fuel filter restriction gauge.   They make troubleshooting much easier, or at least quickly eliminate wrong assumptions.   Does the DDEC show any new codes?

John