Cracked shaft

[RGilliam]

Anyone ever have this happen? It had a gear box on it. It's on a 16hp vanguard.

 

[palm beach]

I thought I cracked it once but it healed right up in a week. No more superman porn moves for me

 

[RGilliam]

 

[RGilliam]

Guess it didn't post the first time.

 

[Ron Musgraves]

Yeah...Sucks

 

[Christopher]

I wonder if it is cost effective to have someone change out the crankshaft?

 

[Russ Johnson]

That come off a direct drive? Looks like the shaft has been hammering back and forth due to gun on / gun off. That shaft is fine with a long key and a taper lock bushing for a belt drive.

 

[RGilliam]

Came off a gear box. I was going to take it to a friends tomorrow and put it on the mill. Cut a slot on the other side.

 

[Sirocco Jerry]

that kind of damage is almost always from cavitation issues..
tank feeding through limited thorofares,
partially plugged filter,
air leak in feed line, or filterbowl,
o-ring bad under a valve seat, cracked head under a valve seat,
etc.
This effect is MUCH more prevelant in high-speed direct drive pumps,
but as you see above, gear-reduction is NOT immune to "shaft-chatter".

we repair engine-shafts in our service dept. regularly.
..on "other peoples pumps" mostly,
but you HAVE to make sure you ALLways have ..
"the PERFECT water supply"

If you tank-feed.. DUAL-FEED that pump, or encur lots of rapair bills.

come to my Troubleshooting and BulletProofing class..
Iowa is the next one !!

 

[Paul Kassander]

Yes that is something I see on older machines. A good quality full length key can help that from happening and checking it every few years or annually is a good idea. Like Russ said it was hammering in there. The softer keys will get kind of loose or malform and cause that. I have rebuild a few engines like that for customers converting to a belt drive like Russ also mentioned.

 

[Sirocco Jerry]

good call Paul.. those shaft keys..
cut one "as long as will fit"
..and tack-weld the end of it onto the shaft so it won't move as easily..
it's your only hope Obi Wan

 

[Russ Johnson]

The biggest problem with gear drives and most direct drives is that they're made for a "slip fit" if you will. A pulley has a setscrew, a sheave has a tapered bushing, and the AR RKV series has a setscrew to lock the key in place.

 

[tomtucson]

'slip fit' - no good, at least at higher horsepower. Will someone make a positive engagement, attachment for a gear drive?

 

[Russ Johnson]

'slip fit' - no good, at least at higher horsepower. Will someone make a positive engagement, attachment for a gear drive?

You'd have to drill through the gear to put a setscrew in. And the gears are hardened.

You'll notice there's never key damage on the pump. It has a setscrew.
Next best setup would be a gearbelt.

Of course, the pump would have to be mounted to the base, and not hung off the engine.