460 oiling problem

[Hillbilly Rick]

Today while logging with stihl 460 w/20" bar I noticed the oil tank was half full when I refueled. I normally run 1:1. I cleaned the oil port and everything under the cover and went back to work, the next thing I know the chain is dry. I removed the bar and started the saw and it wasn't oiling. Went to the shop, cleaned the tank well, had some sawdust in it, then cleaned the filter.Used the air compressor to try to blow out the port, refilled with oil and fired up the saw and still no oil. I hope it's not the oil pump. If so what does it take to fix it?
Any help is greatly appreciated.

 

[TonyRumore]

A few things here. The worm gear drive hook may have broken off. That's a quick cheap fix provided you can pull the clutch yourself. The plastic worm gear may be stripped. That is cheap and quick as well. However, either problem could have been caused by the old pump shaft seizing up in the pump. If that is the case, you can fix the worm gear/drive and then pull the oil pump shaft out of the pump and see if there are some debris, tree pitch, etc, jamming up the shaft. You may be able to just clean it up and get the shaft rotating again. It also needs to move back and forth under it's own spring pressure as well. If the end of the shaft broke off, where it goes into the bronze bushing, you'll have to replace it.

All pretty simple provided you can pull the clutch yourself.

Tony

 

[M-tooth]

All you need to pull the clutch is a piston stop and a socket...dont know the size of the socket off the top of my head. A clean piece of rope with a half dozen knots can also be used as a piston stop in a pinch.

 

[Cody@SPE]

I agree with Tony. Ive worked on a bunch of these saws. With proper maintanance, the oil pump should last a long time. In my opinion, id say the worm gear was shot. Get the whole assemble. You can buy the worm and the gear seperately but replace both and you should be in business!

 

[TonyRumore]

But make sure the oil pump shaft is turning. If it's seized and you put a new worm gear in there, it will just destroy it in short order.

Tony

 

[Cody@SPE]

The socket for the clutch is either a 3/4 or 11/16. Pretty sure its the 3/4

 

[RAMROD48]

Use the black plastic piston stop that came with your saw, and a 19mm socket on a 3/8 drive ratchet. A short length of pipe on the ratchet will turn the clutch off pretty easily (turn to the right). Now pull clutch completly off and remove the cover washer. Inspect the worm gear wire make sure its not broken. Then the plastic gear for stripped threads. Lastly check that the pump is turning free. Then pull the pump out (2 torx 27 screws) make sure the feed hose is open and oil flows free. Now look at the pump, and make sure that the hole that the hose matches up to is not plugged. At this point you are sure everything is clear. Reassemble and make sure the notch in the clutch drum catches the end of the worm gear. Run the saw. Not oiling? Replace the pump. you have exactly 30 minutes with test run time....

GO!:msp_wink:

 

[TonyRumore]

The clutch has left hand threads.

If the oil pump shaft is seized in the body, you'll need a 2mm diameter punch to drift out the pin that retains the oil regulating adjuster (screw). Pull that out, then grab onto the bronze bushing that supports the front of the shaft and turn it while you pull it out. With the bronze bushing out, the oil pump shaft will come out along with it's spring and two washers on each end. Run a 22 caliber brass brush up in the bore and clean it out. Spray it good with some contact cleaner. If the shaft is scored, you can polish it out with some 600 grit sand paper. Then reassemble and check to see if it's turning freely and moving back and forth under it's own spring pressure.

 

[Hillbilly Rick]

Thanks Guys,
My coworker and I are cutting for a sawmill operator and he's supplying the saws (2, 460 mags) So since this requires parts it goes to the shop. I have my own 460 mag though, and will need this info when I need to work on my own saws.
Thanks again,
Rick

 

[Hillbilly Rick]

OK, good news and bad news, My 460 needs a piston and head, so I scavenged the worm gear and hook and put it in the 460 I'm using on the job. The hook was broken but it works now.
Thanks to all who replied,
Rick