Tandem disc; can I remove discs to make it narrower?

[patmajia]

I have a Bush Hog 30-400 disc with 24 discs in 4 gangs, with 7.5" spacing.
I want each gang to be just a bit narrower where it contacts the soil. Can I just remove the nuts, take off one disc, and put the nuts back? I don't see how that would cause any problems. Also, other than just setting the disc down deep in soil, is there a good way to hold it from turning while I loosen the nut?

 

[BTDT]

I don't see that it would hurt a thing. Try it, and if it works, fine, if not, well, maybe someone else will have some ideas. As far as holding it, try clamping vice grips to it real tight, rotate it till it contacts something solid (frame, ground, etc) then wrench the nut off. If that doesn't work, might torch a hole in disc toward center, and insert a bar. Drastic, maybe, but will probably let you get nut off. May end up having to buy new nut anyway, so might be quicker to just torch it off to begin with.

 

[California]

I recently used a big pipe wrench wedged against the ground to hold the opposite end of the disc's axle.

That opposite end is welded to a 4 inch square washer, which was easy to grip with the pipe wrench.

 

[Farmwithjunk]

I have a Bush Hog 30-400 disc with 24 discs in 4 gangs, with 7.5" spacing.
I want each gang to be just a bit narrower where it contacts the soil. Can I just remove the nuts, take off one disc, and put the nuts back? I don't see how that would cause any problems. Also, other than just setting the disc down deep in soil, is there a good way to hold it from turning while I loosen the nut?

You can disassemble each axle and remove the outer disc blade, then re assemble. That'll leave 8" or 9" of axle, nut, and spool to stick out on each corner.

OR.....

Disassemble, cut down axles, reassemble as a smaller disc. You will need to be handy with a welder or a forge to re-form and/or weld the axle end to replicate end that you cut off.

BTDT and here's the pictures. Massey Ferguson #25 disc. First pic is 8'-10" 2 and 3 are the cut-down 7'-6" version. Took about 3 hours start to finish.


Best way I've ever found to loosen/tighten disc axles is with BIG impact wrench.

 

[California]

OR.... trade down.

The disc I got with my Yanmar was claimed to be matched to it - but that was for a flat flood-irrigated walnut orchard. I can't pull it uphill with reasonable speed and adding ballast to make it dig, buries the tractor.

For using it on my slopes I considered removing the outer pans, and operating with the chassis and axles extending beyond the tilled path. But I thought in the orchard I couldn't disc close to the trees without gouging them.

Finally I found the next smaller disc on craigslist for $200. 'Brand New', it said.

I got out there and found it was new pans on a used chassis. 'Thoroughly greased by the dealer then only used once', she told me. After I paid and started loading it, I discovered 1/8" slop in every bearing. There must be various degrees of 'new'.

I got home and found this model (Leinbach 95 or 96) should have 16" pans but this one had been rebuilt with 18" pans, same as my larger disc. (Leinbach 97). So it really is a cut down equivalent of my first disc.

I suppose it is worthwhile even with that much bearing wear, because I won't put many hours on it. The orchard is operated commercially by a neighbor, and my tinkering is just to keep down the Jimson weed and clean up the area near the house, and cross-till some spots his rig is too big to get into.

As I hoped, this smaller disc is just right for 24 hp on land that is not just sloping, but often requires climbing up small terraces between rows.

At this point I'm experimenting with ballast. About 350 lbs makes it dig well and I can still pull it easily uphill as well as downhill. I may still use the larger disc (5'9" vs 3'9") for the final pass to clean up closer to the trees.

I'm still trying to figure out how to set it up to run offset to one side, to get me and the tractor away from the tree branches.

I'm learning about this stuff by trial and error - any comments are welcome.

 

[patmajia]

Did it.
Used a large pipe wrench to keep the whole gang of discs from turning. Used a large crescent wrench on the nut along with a 6' pipe for leverage. Was able to remove one disc from each gang. No problems. Tested out on a few acres without complication.