Sign in to follow this  
Followers 0

520-H Onan PTO Whining/Whistling Noise

6 posts in this topic

I have a 520-H with the P220 Onan motor. For a while it's been whining/whistling when i engage the pto, but as soon as the pto's fully engaged, the noise goes away. This weekend however, the nose persisted for about 10 minutes while i was finishing mowing. It did the whining in the winter with my 2-stage blower hooked up (again, just while it was being engaged, but once fully engaged it was ok). So this weekend the noise became 'permanent' - and i'm afraid it's a bearing that's gonna require a rebuild. It also gets louder with engine speed. Seems the more load is on the pto, the louder and more pronounced it gets.

Is there something I can look at or try to get this to go away without pulling the crank shaft and bearing out? I really dont want to replace the motor.

Thanks in advance!


Share this post

Link to post
Share on other sites

I highly doubt it is the main bearing in the engine. When you push the pto lever forward to engage the pto. The pto cone which the belt rides on has 2 bearings in it. There is a needle bearing, and a regular ball bearing. I recently picked up a 418A and at first I thought it was the deck, so I changed the decks and it still persisted. I turned off the tractor and touched the pto cone by the engine it was warm, and I touched it by the stud which connects to the hoop by a pin and burnt my fingers. My recommendation is to take off the pto cone and see if the ball bearing on the end which is held in my snap clips is shot by spinning it with your fingers. You will know its bad if its loose, makes noise when turning it, or is hard to turn. If it is okay it should have extremely little to no play, and also be smooth and quiet.


Share this post

Link to post
Share on other sites

I pulled the pto cone off today and greased the needle bearings, even though they spun just fine. The other bearing where the pto hook pushed on the pto when its engaged turned but grinded a bit when i spun it. I sprayed every sort of grease and lubricant i could find around it and let it sit for a while. When i put it back, the pto still whined when i engaged it but it wasn't consistently whining while it was running. So i'm pretty confident that if i just got a new cone it would be fine.

Thanks! So glad it's not engine - related :)

Share this post

Link to post
Share on other sites

No problem, it is easier to just replace the outer bearing it comes out by removing the big snap ring, but I would remove the little one first that holds in the stub shaft.

Share this post

Link to post
Share on other sites

Can i get the bearing out by myself without a press? I have a bottle jack and could probably rig something up to make a press. Would the bearing come out just by hitting it enough times strategically with a hammer?

Share this post

Link to post
Share on other sites

So i replaced the ball bearing, and i still have some whining coming out of the pto. I'm wondering if now its the clutch plate behind the bell housing? Also, i picked up a 2nd 520-H and it's got the same issue, so i can't swap parts... Should i look at the clutch plate next? Maybe replace it? The needle bearings look / feel fine to me. Should i also just replace that to do it?


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content
    • GT14 Air Cleaner Adapter Intake
      By VinsRJ
      Hello, looking for a GT14 air filter adapter/intake, specifically the aluminum intake that kicks the air filter outside of the hood.
      Please let me know if you would part with one. PM appreciated.
      Thank, Vince
    • Kohler K301A Rebuilt Engine
      By rgrottk
      Kohler Heavy Duty all Cast Iron Block, 12HP (K301A) Horizontal 1" Shaft Tractor Engine.
      Uses battery (point) ignition Delco Remy Gen/Starter. Engine has Full Power, Starts easily (has compression release) and does not smoke. Engine completely re-built new piston, rings (chrome), the cylinder cast iron bore was honed to specs, new Head Gasket and Pan gasket. Carburetor rebuilt with new, seals, seat and needle valve. Delco Remy Generator and Voltage Circuit is good. Came out of a Cub Cadet (127) Tractor and comes with the mounted Drive Take Off. Engine can be installed on many tractors which use a Horizontal shaft engine, John Deere, Cub Cadet, Bolen, Wheel Horse and Sears Suburban etc. Test Gas Tank and muffler do not come with the unit.

      Engine can be seen, run at my home in Brewster NY and is sold as is. Must be picked-up too heavy to ship.

      If you are seriously interested send me your e-mail address and I will send you a .MP4 file which demonstrates how well it starts and runs.

    • 417A - full of GUNK
      By Kegler
      Acquired locally a 417A with a bunch (3000+) hrs on the meter, but a jump got it running and for $200 I drove it  home. Came with a blade too.    Thought the price was right considering it had a 48" deck mounted that looks to be in much better shape than the rest of the tractor. As I said I did drive it the few blocks home with an occasional pop or crack from the motor that I attributed to possibly a sticking valve or even just some old gas. Parked it and tossed a tarp half over it until I could get a chance to work on it, which turned out to be longer than expected. Anyway, to the problem, I went out a couple of days ago and put a charger on it for a while and tried to start it and it turned over about a quarter turn and locked up, so I pulled the spark plugs and tried the starter again and the worst looking junk I had ever seen in a motor came squirting out of the plug holes. Whats up with that? How would a motor fill up with GUNK, even setting outside? Shot a bunch of PB Blaster in both plug holes to try to loosen up any rust or junk in the cylinders but would like to figure out where it got into the cylinders, in the first place, before I go any further with trying to save it. Motor appears to have all the tin, air cleaner and muffler on it.
    • WANTED: Working Kohler K181
      By mr_speegs
      I'm looking for a working Kohler K181 of any variant that has good compression and little/no smoking on start up. I do not necessarily need a carb, generator, or fuel tank.
      Cosmetics are not a consideration.
      I would be interested in picking up the engine at the PA show in June (or any other reasonable or local arrangement).
      Please PM me with any pictures/video and your asking price. Evidence of good compression/no smoke would be much appreciated. Thanks!

    • C121 will not crank
      By kcuttuck
      My 1978 C121 will not start. It will not crank over. The voltage at the battery post on the key switch is 12.3 volts. When I turn the key to the run position the voltage at the battery post on the key switch drops off.
      I tested the clutch switch. good
      Replaced the key switch.
      Seat switch is bypassed. 
      I am suspecting the PTO interlock switch but I have no idea how it works and how to test it. I am very mechanically inclined but I have never seen a switch like that before. 
      Help Please.