Mystery random grinding sound

[cummins90]

This happens if cold or hot, running for a minute or after hours of use.

Kubota L245DT grinding sound.

youtube.com

Shutting the engine down and restarting stops the grinding whirling noise. Maybe it's starter related.

 

[DustyRusty]

Sounds like the Bendix spring isn't releasing from the flywheel occasionally.

 

[cummins90]

It's odd that it will start up and run fine then randomly start making the sound.

The starter needs to be serviced anyways. I takes a few times to get the starter to actually spin.

 

[DustyRusty]

It's odd that it will start up and run fine then randomly start making the sound.

The starter needs to be serviced anyways. I takes a few times to get the starter to actually spin.

While it is out, check the flywheel all the way around for any worn or broken teeth. You can usually remove the lower flywheel cover and use a large flat-blade screwdriver to slowly turn the flywheel. Just mark the starting point with chalk or crayon. It only takes one broken tooth to mess up your day when the starter hits just that one spot and the engine won't crank. It happened on an old 6-cylinder Chevy that I had, and the only way to fix it was to put the car into gear and rock it a little to move the flywheel.

 

[North Idaho Wolfman]

Throw out bearing!

 

[cummins90]

Next time it happens I'll work the clutch to see if it changes.

 

[DustyRusty]

Throw out bearing!

If he throws out the bearing what is the clutch going to ride on? This was the thread that I was having problems responding to.

 

[rbargeron]

I agree it sounds like a dry throw out bearing. Try adjusting the clutch so it has about 1-1/2" of free play at the top. If the pto won't disengage, try 1-1/4". Post back if adjusting it affects the noise.

 

[cummins90]

I checked the free play and it's about 1.5 inch so I left it. I've been running the machine almost everyday for hours at a time. The sound has not happened since I posted about it so probably just a dry bearing.

 

[cummins90]

Kubota l245dt shot water pump

youtube.com

May have found the source of the grinding sound. Replaced it with a Keba? Brand pump. It has a plastic impeller but the machine work looked good enough and it fit.

 

[D2Cat]

Kubota l245dt shot water pump

youtube.com

May have found the source of the grinding sound. Replaced it with a Keba? Brand pump. It has a plastic impeller but the machine work looked good enough and it fit.

Yes, a bit too much play. It's nice to know what the problem is before beginning to throw parts at it. Much better results!

 

[rbargeron]

Good doing !! Its surprising the water pump bearing could be that worn without coolant spewing out too. Its testimony to the design priorities of Kubota - engine preservation is at the top, failure of a water pump bearing doesn't immediately take out its seal.

High build quality is the reason so many older Kubotas are still functioning - and have a following of young buyers these days.

 

[GeoHorn]

re: plastic impeller in a water pump: I have a JD 4239 engine in a compactor/roller…. which started overheating. It was a long discovery process….changed thermostat… changed suspected collapsed hoses…cleaned radiator…. yada yada yada…

..then one day discovered no water movement in the radiator despite the removed thermostat…Hmmnn…

Pulled the water pump. Plastic/Phenolic impeller…. spins on the steel shaft. I.E., the pulley and shaft spins…. so does the impeller…. except the impeller doesn’t spin at the same speed as the shaft…and with Zero Force to move water.

Changed that pump to one with a cast-iron impeller…. No More Problem!

It’s my belief that the plastic/phenolic impeller hasn’t the “grip” onto the shaft that all-metal pumps have…..as the plastic and the metal shaft have different expansion-rate properties when things heat up….and continuous vibration…..eventually that impeller loses it’s grip.

 

[cummins90]

The plastic impeller is bolted on. The original cast impeller was pressed on.