Bush Hog pan fell off!

[daveinnh]

I bought a used Bush Hog 306 rotary mower last Sept. While mowing fields last week, I hit some rocks, heard a commotion behind the Kubota tractor, and saw that the pan with blades fell off.

My wife has a horse (I'm the Asst. manure manager) so I used his magnetic floor magnet to fit the nut & washer in the grass. (we use it to find nails after the farrier leaves).

Two topics:

1. However, the nut is just a large standard item - not a castle -type with cotter pin to ensure mount retainage. I saw a thread elsewhere that recommended a tack weld to retain the nut position.
2. I saw a small "key" from Messick's for about $16 / ea. for 3/8 x 3/8 x 1.25". If I wanted to buy bar stock and cut-to-fit: what grade(s) steel would be appropriate?

Any other options to tack weld?

Thanks,
daveinnh

 

[Semper Paratus]

1018 steel would probably be appropriate. The strength of the 1018 key will be pretty close to that of the bush hog shaft and stunp jumper disk. You might try your autoparts store to see if they have a front wheel spindle castle nut of the appropriate size and pitch...of course that means a drilled hole through the shaft for the cotter pin. Non permanent medium strength lock tite might be something to consider. Another option would be to drill and tap, through the nut flats for a 10-24 or 1/4"-20 set screw and install that with non permanent lock tite once the main nut is set and torqued. If I was going to tack weld it I would tack the flat of the nut to the stump jumper disk instead of tacking the nut to the shaft less risk of irreversible damage to the threaded portions of the shaft...Just my humble opinion.

 

[ruffdog]

I'm not a fan of tack welding. I would rather use lock-tite. Common key stock is either 1018-1045 low carbon steel or 4140 for tougher applications.

McMaster-Carr

 

[WranglerX]

Manual says to torque nut to 600FT-LBS (on page 11) ..... Should not need tac weld or locktite...

https://bushhog.com/wp-content/uploads/2020/02/BHRotaryCutter305-306OM-03.pdf

 

[cathy liebchen]

Bush Hog sells all the parts for that model just call them they are in Selma Al or use the online parts lookup

 

[LD1]

306 is a darn good and tough cutter. Had one for years.

For the key.....just get a piece of key-stock the right size. Cut whatever length you need. Napa should stock the stuff.

As to the nut....I also am not a fan of tack welding. I dont know your capabilities.....but several ideas come to mind to retain the nut...

Loctite (red), lock washer, drill and tap the nut for a set screw to lock onto the threads and if the nut is thick enough....double set-screw to prevent it from backing out, drill all the way through the nut .....thread it on and drill all the way through the shaft and use a cotter, you can also take a punch and chisel and stake the threads or nut, if you can measure the nut and thread pitch, you can get a lock nut

Those are just a few examples of various ways I have seen nuts captured before

But I'd check the shaft and stump jumper (pan) out real good. IT would be pretty odd for the nut to back all the way off and drop the pan all at once. So I fear it may have been loose for awhile. Those are usually a tapered shaft.....so with a loose nut and pan it could have did some wollering out of the shaft/bore/keyway. Make sure things look good and fit snug.